120 results on '"Veron V"'
Search Results
2. Water exchange rate in RAS and dietary inclusion of micro-minerals influence growth, body composition and mineral metabolism in common carp
- Author
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Antony Jesu Prabhu, P., Kaushik, S.J., Geurden, I., Stouten, T., Fontagné-dicharry, S., Veron, V., Mariojouls, C., Verreth, J.A.J., Eding, E.H., and Schrama, J.W.
- Published
- 2017
- Full Text
- View/download PDF
3. Optimization of embryonic thermal programming confirms increased liver fattening in mule ducks and changes in lipid metabolism
- Author
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Andrieux, C., primary, Marchand, M., additional, Larroquet, L., additional, Veron, V., additional, Biasutti, S., additional, Morisson, M., additional, Coustham, V., additional, Panserat, S., additional, and Houssier, M., additional
- Published
- 2023
- Full Text
- View/download PDF
4. A plant-based diet differentially affects the global hepatic methylome in rainbow trout depending on genetic background
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Marandel L, Heraud C, Véron V, Laithier J, Marchand M, Quillet E, Callet T, Dupont-Nivet M, and Médale F
- Subjects
isogenic lines ,dna methylation intermediates ,hplc-uv ,5-hydroxymethyl-cytosine ,5-carboxycytosine ,5-formylcytosine ,5-methylcytosine ,Genetics ,QH426-470 - Abstract
Replacing fish meal and oil in trout diets with plant-derived ingredients is a contemporary challenge to move towards more sustainable aquaculture practices. However, such dietary replacement causes hepatic metabolic changes that have not yet been elucidated. Here, we aimed to decipher the effect of a 100% plant-based diet on the hepatic global DNA methylation landscape in trout and assess whether changes depend on fish genetic background. We analysed the global methylome and the expression of DNA (de)methylation-related genes of three isogenic lines that exhibit similar growth when fed a marine resource-based diet (M diet), but differ in their responses to a plant-based diet (V diet). Our results revealed that the V diet induced a decrease in 5-cytosine combined with an increase in 5-hydroxymethylcytosine in two of the three analysed lines. For one of these 2 affected lines, when fed the M diet but at the same feed intake of the V diet (MR), no methylome differences were highlighted between M and MR or between MR and V-fed trout whereas for the other affected line, M fed trout displayed a divergent methylome profile from MR and V fed fish. DNA (de)methylation-related genes were also affected by the V or MR diets. Our findings showed that the global hepatic methylome of trout is affected by a V diet, depending on genetic background. This latter effect seems to be due to either a decreased feed intake alone or combined with the effect of the dietary composition per se.
- Published
- 2022
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- View/download PDF
5. Molecular diversity of arbuscular mycorrhizal fungi associated with some plant species in New Caledonian serpentine and non-serpentine ecosystems
- Author
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Gensous, S., Amir, H., VERON, V., Cavaloc, Y., BUNC, Pole ID, Laboratoire Insulaire du Vivant et de l'Environnement (LIVE), and Université de la Nouvelle-Calédonie (UNC)
- Subjects
[SDV] Life Sciences [q-bio] ,[SDV]Life Sciences [q-bio] - Published
- 2014
6. High or low dietary carbohydrate: protein ratios during first-feeding affect glucose metabolism and intestinal microbiota in juvenile rainbow trout
- Author
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Geurden, I., Mennigen, J., Plagnes-juan, E., Veron, V., Cerezo, T., Mazurais, David, Zambonino-infante, Jose-luis, Gatesoupe, Joel, Skiba-cassy, S., Panserat, S., Geurden, I., Mennigen, J., Plagnes-juan, E., Veron, V., Cerezo, T., Mazurais, David, Zambonino-infante, Jose-luis, Gatesoupe, Joel, Skiba-cassy, S., and Panserat, S.
- Abstract
Based on the concept of nutritional programming in mammals, we tested whether an acute hyperglucidic-hypoproteic stimulus during first feeding could induce long-term changes in nutrient metabolism in rainbow trout. Trout alevins received during the five first days of exogenous feeding either a hyperglucidic (40% gelatinized starch + 20% glucose) and hypoproteic (20%) diet (VLP diet) or a high-protein (60%) glucose-free diet (HP diet, control). Following a common 105-day period on a commercial diet, both groups were then challenged (65 days) with a carbohydrate-rich diet (28%). Short-and long-term effects of the early stimuli were evaluated in terms of metabolic marker gene expressions and intestinal microbiota as initial gut colonisation is essential for regulating the development of the digestive system. In whole alevins (short term), diet VLP relative to HP rapidly increased gene expressions of glycolytic enzymes, while those involved in gluconeogenesis and amino acid catabolism decreased. However, none of these genes showed persistent molecular adaptation in the liver of challenged juveniles (long term). By contrast, muscle of challenged juveniles subjected previously to the VLP stimulus displayed downregulated expression of markers of glycolysis and glucose transport (not seen in the short term). These fish also had higher plasma glucose (9 h postprandial), suggesting impaired glucose homeostasis induced by the early stimulus. The early stimulus did not modify the expression of the analysed metabolism-related microRNAs, but had short-and long-term effects on intestinal fungi (not bacteria) profiles. In summary, our data show that a short hyperglucidic-hypoproteic stimulus during early life may have a long-term influence on muscle glucose metabolism and intestinal microbiota in trout.
- Published
- 2014
- Full Text
- View/download PDF
7. High or low dietary carbohydrate:protein ratios during first-feeding affect glucose metabolism and intestinal microbiota in juvenile rainbow trout
- Author
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Geurden, I., primary, Mennigen, J., additional, Plagnes-Juan, E., additional, Veron, V., additional, Cerezo, T., additional, Mazurais, D., additional, Zambonino-Infante, J., additional, Gatesoupe, J., additional, Skiba-Cassy, S., additional, and Panserat, S., additional
- Published
- 2014
- Full Text
- View/download PDF
8. First results on the behavior of young stages of allis shad Alosa alosa
- Author
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Veron, V., Philippe Jatteau, Bardonnet, A., Institut National de la Recherche Agronomique (INRA), Ressources aquatiques continentales (UR RABX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), ENSAR RENNES, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Ecobiologie et qualité des hydrosystèmes continentaux (EQHC), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure Agronomique de Rennes, Station d'hydrobiologie, and Irstea Publications, Migration
- Subjects
[SDE] Environmental Sciences ,[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience; Experiments were performed to investigate the use of space by larvae of allis shad Alosa alosa (also known as allice shad) under experimental conditions. Soon after hatching, larvae swam actively toward the surface and sank down passively to swim up again once they reached the bottom. After this phase, most of the larvae swam in the first cm below the water surface. This general pattern of water column use was observed with and without water current and irrespective of the size of the bottom substrate material. The ontogeny of larval swimming behavior has been studied in an artificial stream.The first experimental work on allis shad larval behavior, suggests a pelagic larval mode immediately after hatching. Because of a high proportion of drifting fish, most larvae would undergo a large downstream dispersal in the wild.
- Published
- 2003
9. International study to evaluate PCR methods for detection of Trypanosoma cruzi DNA in blood samples from Chagas disease patients.
- Author
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Schijman,AG, Bisio,M, Orellana,L, Sued,M, Duffy,T, Mejia Jaramillo,AM, Cura,C, Auter,F, Veron,V, Qvarnstrom,Y, Deborggraeve,S, Hijar,G, Zulantay,I, Lucero,RH, Velazquez,E, Tellez,T, Sanchez Leon,Z, Galvão,L, Nolder,D, Monje Rumi,M, Levi,JE, Ramirez,JD, Zorrilla,P, Flores,M, Jercic,MI, Crisante,G, Añez,N, De Castro,AM, Gonzalez,CI, Acosta Viana,K, Yachelini,P, Torrico,F, Robello,C, Diosque,P, Triana Chavez,O, Aznar,C, Russomando,G, Büscher,P, Assal,A, Guhl,F, Sosa Estani,S, DaSilva,A, Britto,C, Luquetti,A, Ladzins,J, Schijman,AG, Bisio,M, Orellana,L, Sued,M, Duffy,T, Mejia Jaramillo,AM, Cura,C, Auter,F, Veron,V, Qvarnstrom,Y, Deborggraeve,S, Hijar,G, Zulantay,I, Lucero,RH, Velazquez,E, Tellez,T, Sanchez Leon,Z, Galvão,L, Nolder,D, Monje Rumi,M, Levi,JE, Ramirez,JD, Zorrilla,P, Flores,M, Jercic,MI, Crisante,G, Añez,N, De Castro,AM, Gonzalez,CI, Acosta Viana,K, Yachelini,P, Torrico,F, Robello,C, Diosque,P, Triana Chavez,O, Aznar,C, Russomando,G, Büscher,P, Assal,A, Guhl,F, Sosa Estani,S, DaSilva,A, Britto,C, Luquetti,A, and Ladzins,J
- Abstract
A century after its discovery, Chagas disease still represents a major neglected tropical threat. Accurate diagnostics tools as well as surrogate markers of parasitological response to treatment are research priorities in the field. The purpose of this study was to evaluate the performance of PCR methods in detection of Trypanosoma cruzi DNA by an external quality evaluation.
- Published
- 2011
10. Upstream migration and reproductive patterns of a population of allis shad in a small river (L'Aulne, Brittany, France)
- Author
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Acolas, M, Veron, V, Jourdan, H, Begout, Marie-laure, Sabatie, M, Bagliniere, J.l., Acolas, M, Veron, V, Jourdan, H, Begout, Marie-laure, Sabatie, M, and Bagliniere, J.l.
- Abstract
The characteristics and activity of adult allis shad [Alosa alosa (L.)] were analysed during the last part of their upstream migration in the L'Aulne, a small river in Brittany, and during reproduction on a unique spawning ground downstream of an insurmountable dam. The age of the spawners ranged front three to seven years, females being larger and older than males. Population-level migration and reproduction were studied by counting the number of migrating fish, by estimating the sex ratio, and by counting the number of nocturnal spawning acts for three consecutive years starting in 2000. The influence of the environment, especially water temperature and discharge, was highlighted: temperature during migration may supplant the influence of water flow, although high flow could allow passage over the dam. Such factors partly explain the annual pattern of migration and reproduction during the spawning season. The study showed that the biological features and characteristics of this Population of allis shad in a small river were similar to those of western Atlantic stocks in large rivers. (c) 2005 International Council for the Exploration of the Sea.
- Published
- 2006
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11. Fine-scale genetic structure and gene dispersal inferences in 10 Neotropical tree species
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Hardy, Olivier J., Maggia, L., Bandou, E, Breyne, P., Caron, H, Chevallier, MH, Doligez, A, Dutech, C., Kremer, Jan Am, Latouche-Hallé, C., Troispoux, V, Veron, V, Degen, B, Hardy, Olivier J., Maggia, L., Bandou, E, Breyne, P., Caron, H, Chevallier, MH, Doligez, A, Dutech, C., Kremer, Jan Am, Latouche-Hallé, C., Troispoux, V, Veron, V, and Degen, B
- Abstract
The extent of gene dispersal is a fundamental factor of the population and evolutionary dynamics of tropical tree species, but directly monitoring seed and pollen movement is a difficult task. However, indirect estimates of historical gene dispersal can be obtained from the fine-scale spatial genetic structure of populations at drift-dispersal equilibrium. Using an approach that is based on the slope of the regression of pairwise kinship coefficients on spatial distance and estimates of the effective population density, we compare indirect gene dispersal estimates of sympatric populations of 10 tropical tree species. We re-analysed 26 data sets consisting of mapped allozyme, SSR (simple sequence repeat), RAPD (random amplified polymorphic DNA) or AFLP (amplified fragment length polymorphism) genotypes from two rainforest sites in French Guiana. Gene dispersal estimates were obtained for at least one marker in each species, although the estimation procedure failed under insufficient marker polymorphism, limited sample size, or inappropriate sampling area. Estimates generally suffered low precision and were affected by assumptions regarding the effective population density. Averaging estimates over data sets, the extent of gene dispersal ranged from 150 m to 1200 m according to species. Smaller gene dispersal estimates were obtained in species with heavy diaspores, which are presumably not well dispersed, and in populations with high local adult density. We suggest that limited seed dispersal could indirectly limit effective pollen dispersal by creating higher local tree densities, thereby increasing the positive correlation between pollen and seed dispersal distances. We discuss the potential and limitations of our indirect estimation procedure and suggest guidelines for future studies., FLWIN, info:eu-repo/semantics/published
- Published
- 2006
12. An assessment of the upstream migration and reproductive behaviour of allis shad (Alosa alosa L.) using acoustic tracking
- Author
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Acolas, Ml, Begout Anras, Marie-laure, Veron, V, Jourdan, H, Sabatie, Mr, Bagliniere, Jl, Acolas, Ml, Begout Anras, Marie-laure, Veron, V, Jourdan, H, Sabatie, Mr, and Bagliniere, Jl
- Abstract
We provide a detailed description of the migratory and reproductive behaviour of allis shad (Alosa alosa L.), a species that is in decline in Europe. Adult swimming behaviour during the last part of upstream migration and on a spawning ground downstream of an insurmountable dam was studied in detail and its main features identified. "characterized" in this context. Mobile telemetry and a fixed telemetry system were used to record fish positions and to monitor 23 acoustically tagged individuals (17 females and six males) during the 2001 and 2002 reproductive seasons. Allis shad showed considerable exploratory behaviour, and a rest area was observed 1.5 km downstream of the spawning ground. Thirteen individuals were observed on the spawning area, though both males and females spent most of their time (70-99%) away from it. Male and female residency times on the spawning area were, respectively, 1-11 days and 1-7 days, and females were observed during both day and night on the spawning ground. In 2002, an analysis of the 3D swimming behaviour on the spawning ground of six individuals allowed us to estimate the number of spawning events per fish. Males participated in more spawning acts (up to 60) than females (0-2). (C) 2004 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All tights reserved.
- Published
- 2004
- Full Text
- View/download PDF
13. Gene flow and mating system of the tropical tree Sextonia rubra
- Author
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Veron, V., primary, Caron, H., additional, and Degen, B., additional
- Published
- 2005
- Full Text
- View/download PDF
14. High or low dietary carbohydrate:protein ratios during firstfeeding affect glucose metabolism and intestinal microbiota in juvenile rainbow trout.
- Author
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Geurden, I., Mennigen, J., Plagnes-Juan, E., Veron, V., Cerezo, T., Mazurais, D., Zambonino-lnfante, J., Gatesoupe, J., Skiba-Cassy, S., and Panserat, S.
- Subjects
RAINBOW trout ,LOW-calorie diet ,FISH feeds ,CARBOHYDRATES in animal nutrition ,PROTEINS in animal nutrition ,GLUCOSE metabolism ,GUT microbiome ,GENE expression in fishes - Abstract
Based on the concept of nutritional programming in mammals, we tested whether an acute hyperglucidic-hypoproteic stimulus during first feeding could induce long-term changes in nutrient metabolism in rainbow trout. Trout alevins received during the five first days of exogenous feeding either a hyperglucidic (40% gelatinized starch + 20% glucose) and hypoproteic (20%) diet (VLP diet) or a high-protein (60%) glucose-free diet (HP diet, control). Following a common 105- day period on a commercial diet, both groups were then challenged (65 days) with a carbohydrate-rich diet (28%). Short- and long-term effects of the early stimuli were evaluated in terms of metabolic marker gene expressions and intestinal microbiota as initial gut colonisation is essential for regulating the development of the digestive system. In whole alevins (short term), diet VLP relative to HP rapidly increased gene expressions of glycolytic enzymes, while those involved in gluconeogenesis and amino acid catabolism decreased. However, none of these genes showed persistent molecular adaptation in the liver of challenged juveniles (long term). By contrast, muscle of challenged juveniles subjected previously to the VLP stimulus displayed downregulated expression of markers of glycolysis and glucose transport (not seen in the short term). These fish also had higher plasma glucose (9 h postprandial), suggesting impaired glucose homeostasis induced by the early stimulus. The early stimulus did not modify the expression of the analysed metabolism-related microRNAs, but had short- and long-term effects on intestinal fungi (not bacteria) profiles. In summary, our data show that a short hyperglucidic-hypoproteic stimulus during early life may have a long-term influence on muscle glucose metabolism and intestinal microbiota in trout. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
15. PREMIÈRE CARACTÉRISATION MORPHOLOGIQUE, BIOLOGIQUE ET GÉNÉTIQUE DES POPULATIONS DE GRANDE ALOSE (ALOSA ALOSA) ET D’ALOSE FEINTE (ALOSA FALLAX SPP.) DE LA CHARENTE (FRANCE).
- Author
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VÉRON V., SABATIÉ R., BAGLINIÈRE J. L., and ALEXANDRINO P.
- Subjects
Alosa alosa ,Alosa fallax ,Charente ,France ,morphology ,biology ,ecology ,genetics ,Aquaculture. Fisheries. Angling ,SH1-691 - Abstract
Les deux espèces d’aloses atlantiques (Alosa alosa et A. fallax) colonisent la Charente mais leurs populations n’ont jamais été décrites à la différence de celles des grands fleuves français voisins. Les propriétés physiques du bassin sont présentées en terme de qualité de l’eau, d’habitats et d’obstacles à la migration. Les grandes aloses colonisent la Charente jusqu’en amont d’Angoulême (171 km) lorsque les conditions hydrauliques des mois d’avril et mai effacent les 21 barrages situés en aval. Des frayères actives ont été localisées sur cette portion du fleuve. Les aloses feintes sont bloquées plus en aval par le barrage de Crouin (102 km, aval de Cognac) et une seule frayère active a été repérée. L’abondance de ces deux stocks d’alose ne peut pas être estimée car les seules données disponibles, faute de dispositifs de contrôle des migrations, proviennent des captures faites par pêche professionnelle et à la ligne. La caractérisation morphologique et génétique des deux espèces a été faite à partir de comptages méristiques, de mesures morphométriques et de prélèvements (écaille, tissus et sang) réalisés en 1997 et 1998. Le nombre total moyen de branchiospines du premier arc branchial gauche chez les grandes aloses est de 125 contre 42 chez les feintes. Quelle que soit l’espèce et à âge égal, les femelles ont une taille moyenne supérieure à celle des mâles. Les femelles de grande alose sont âgées en moyenne de 5 ans et les mâles de 4 ans, aucun des poissons échantillonnés ne présentant de marques de reproduction antérieure. Les femelles et les mâles d’alose feinte sont âgés en moyenne de 3 ans, 12,5 % des femelles se sont déjà reproduites une fois et 3,5 % deux fois. Chez les mâles, 40 % se sont déjà reproduits une fois. La plage temporelle de reproduction a été déterminée par suivi de terrain et enquête. Celle des grandes aloses se situe entre la première quinzaine de mai et la première quinzaine de juin. Celle des aloses feintes au cours de la seconde quinzaine de mai et la première quinzaine de juin. La comparaison de leurs caractéristiques à celle des populations déjà étudiées montre qu’elles restent assez proches des stocks ligériens. La caractérisation génétique des deux stocks a été effectuée par électrophorèse des protéines (8 locus). Celle des grandes aloses de la Charente présente des distributions de fréquences alléliques relativement proches de celles des populations caractérisées antérieurement mais se distingue par des taux d’hétérozygotie plus faible et par un plus grand nombre de locus hétérozygotes. Globalement, les aloses feintes de la Charente apparaissent beaucoup moins polymorphes que celles de l’ensemble des populations atlantiques étudiées. La comparaison globale des populations françaises, portugaises et marocaines par l’analyse des distances génétiques confirme le caractère très peu polymorphe des populations de grande alose par rapport à celles d’alose feinte.
- Published
- 2001
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16. Genetic diversity of msp3α and msp1_b5 markers of Plasmodium vivax in French Guiana
- Author
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Carme Bernard, Simon Stéphane, Volney Béatrice, Yrinesi Joséphine, Legrand Eric, and Véron Vincent
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Reliable molecular typing tools are required for a better understanding of the molecular epidemiology of Plasmodium vivax. The genes msp3a and msp1_block5 are highly polymorphic and have been used as markers in many P. vivax population studies. These markers were used to assess the genetic diversity of P. vivax strains from French Guiana (South America) and to develop a molecular typing protocol. Methods A total of 120 blood samples from 109 patients (including 10 patients suffered from more than one malaria episode, samples were collected during each episode) with P. vivax infection were genotyped. All samples were analysed by msp3a PCR-RFLP and msp1_b5 gene sequencing was performed on 57 samples. Genotyping protocol applied to distinguish between new infection or relapse from heterologus hypnozoites and treatment failure or relapse from homologus hypnozoites was based on analysing first msp3a by PCR-RFLP and secondly, only if the genotypes of the two samples are identical, on sequencing the msp1_b5 gene. Results msp3a alleles of three sizes were amplified by PCR: types A, B and C. Eleven different genotypes were identified among the 109 samples analysed by msp3a PCR-RFLP. In 13.8% of cases, a mixed genotype infection was observed. The sequence of msp1_b5 gene revealed 22 unique genotypes and 12.3% of cases with mixed infection. In the 57 samples analysed by both methods, 45 genotypes were found and 21% were mixed. Among ten patients with two or three malaria episodes, the protocol allowed to identify five new infections or relapses from heterologous hypnozoites and six treatment failures of relapses from homologous hypnozoites. Conclusion The study showed a high diversity of msp3a and msp1_b5 genetic markers among P. vivax strains in French Guiana with a low polyclonal infection rate. These results indicated that the P. vivax genotyping protocol presented has a good discrimination power and can be used in clinical drug trials or epidemiological studies.
- Published
- 2009
- Full Text
- View/download PDF
17. Unique Gene Expression Profiles within South Africa Are Associated with Varied Chemotherapeutic Responses in Conventional Osteosarcoma.
- Author
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Mthethwa PG, Arumugam T, Ramsuran V, Gokul A, Rodseth R, and Marais L
- Abstract
Background: We determined the predictive gene expression profiles associated with chemo-response in conventional osteosarcomas (COS) within South Africa., Materials and Methods: In 28 patients, we performed an RNA extraction, cDNA synthesis, and quantitative analysis using the RT-PCR 2
-∆∆CT method to determine the fold change in gene expression alongside GAPDH (housekeeping gene)., Results: We observed a significant downregulation in the mRNA expression profiles of ABCB1-p-glycoprotein ( p = 0.0007), ABCC3 ( p = 0.002), ERCC1 ( p = 0.007), p-53 ( p = 0.007), and RFC1 ( p = 0.003) in the COS patients compared to the healthy donors. Furthermore, ABCB1-p-glycoprotein ( p = 0.008) and ABCC3 ( p = 0.020) exhibited a significant downregulation in the COS tumour tissues when compared to the healthy donors. In our univariate logistic regression, the predictors of chemotherapeutic response comprised ERCC1 [restricted cubic spline (RCS) knot: OR -0.27; CI -0.504 to -0.032; p = 0.036]; osteoblastic subtype [OR -0.36; CI -0.652 to -0.092; p = 0.026); fibroblastic subtype [OR 0.91; CI 0.569 to 1.248; p < 0.001]; and mixed subtype [OR 0.53; CI 0.232 to 0.032; p = 0.032]. In our multivariable logistic regression, the significant predictors of chemotherapeutic response comprised age [RCS knot: OR -2.5; CI -3.616 to -1.378; p = 0.022]; ABCC3 [RCS knot: OR 0.67; CI 0.407 to 0.936, p = 0.016]; ERCC1 [RCS knot: OR 0.57; CI 0.235 to 0.901; p = 0.044]; RFC1 [RCS knot: OR -1.04; CI -1.592 to -0.487; p = 0.035]; chondroblastic subtype [OR -0.83; CI -1.106 to -0.520; p = 0.012]; and osteoblastic subtype [OR -1.28; CI -1.664 to -0.901; p = 0.007]., Conclusions: In this South African cohort, we observed the unique gene expression profiles of osteosarcoma tumourigenesis and chemotherapeutic responses. These may serve as prognostication and therapeutic targets. Larger-scale research is needed on the African continent.- Published
- 2024
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18. Variation within the non-coding genome influences genetic and epigenetic regulation of the human leukocyte antigen genes.
- Author
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Arumugam T, Adimulam T, Gokul A, and Ramsuran V
- Subjects
- Humans, Gene Expression Regulation, Polymorphism, Single Nucleotide, Genetic Variation, RNA, Untranslated genetics, MicroRNAs genetics, Epigenesis, Genetic, DNA Methylation, HLA Antigens genetics
- Abstract
Variation within the non-coding genome may influence the regulation and expression of important genes involved in immune control such as the human leukocyte antigen (HLA) system. Class I and Class II HLA molecules are essential for peptide presentation which is required for T lymphocyte activation. Single nucleotide polymorphisms within non-coding regions of HLA Class I and Class II genes may influence the expression of these genes by affecting the binding of transcription factors and chromatin modeling molecules. Furthermore, an interplay between genetic and epigenetic factors may also influence HLA expression. Epigenetic factors such as DNA methylation and non-coding RNA, regulate gene expression without changing the DNA sequence. However, genetic variation may promote or allow genes to escape regulation by epigenetic factors, resulting in altered expression. The HLA system is central to most diseases, therefore, understanding the role of genetics and epigenetics on HLA regulation will tremendously impact healthcare. The knowledge gained from these studies may lead to novel and cost-effective diagnostic approaches and therapeutic interventions. This review discusses the role of non-coding variants on HLA regulation. Furthermore, we discuss the interplay between genetic and epigenetic factors on the regulation of HLA by evaluating literature based on polymorphisms within DNA methylation and miRNA regulatory sites within class I and Class II HLA genes. We also provide insight into the importance of the HLA non-coding genome on disease, discuss ethnic-specific differences across the HLA region and provide guidelines for future HLA studies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Arumugam, Adimulam, Gokul and Ramsuran.)
- Published
- 2024
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19. High Resolution Class I HLA -A, -B , and - C Diversity in Eastern and Southern African Populations.
- Author
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Banjoko AW, Ng'uni T, Naidoo N, Ramsuran V, Hyrien O, and Ndhlovu ZM
- Abstract
Africa remains significantly underrepresented in high-resolution Human Leukocyte Antigen (HLA) data, despite being one of the most genetically diverse regions in the world. This critical gap in genetic information poses a substantial barrier to HLA-based research on the continent. In this study, Class I HLA data from Eastern and Southern African populations were analysed to assess genetic diversity across the region. We examined allele and haplotype frequency distributions, deviations from Hardy-Weinberg Equilibrium (HWE), linkage disequilibrium (LD), and conducted neutrality tests of homozygosity across various populations. Additionally, the African HLA data were compared to those of Caucasian and African American populations using the Jaccard index and multidimensional scaling (MDS) methods. The study revealed that South African populations exhibited 50.4% more genetic diversity within the Class I HLA region compared to other African populations. Zambia showed an estimated 36.5% genetic diversity, with Kenya, Rwanda and Uganda showing 35.7%, 34.2%, and 31.1%, respectively. Furthermore, an analysis of in-country diversity among different tribes indicated an average Class I HLA diversity of 25.7% in Kenya, 17% in Rwanda, 2.8% in South Africa, 13.6% in Uganda, and 6.5% in Zambia. The study also highlighted the genetic distinctness of Caucasian and African American populations compared to African populations. Notably, the differential frequencies of disease-promoting and disease-preventing HLA alleles across these populations emphasize the urgent need to generate high-quality HLA data for all regions of Africa and its major ethnic groups. Such efforts will be crucial in enhancing healthcare outcomes across the continent., Competing Interests: DECLARATION OF INTERESTS The authors declare no competing interests.
- Published
- 2024
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20. HLA-B and C Expression Contributes to COVID-19 Disease Severity within a South African Cohort.
- Author
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Naidoo L, Arumugam T, and Ramsuran V
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, Cohort Studies, RNA, Messenger genetics, RNA, Messenger metabolism, South Africa epidemiology, COVID-19 genetics, COVID-19 virology, COVID-19 ethnology, HLA-B Antigens genetics, HLA-C Antigens genetics, SARS-CoV-2, Severity of Illness Index
- Abstract
Globally, SARS-CoV-2 has negatively impacted many lives and industries due to its rapid spread, severe outcomes, and the need for the implementation of lockdown strategies across the world. SARS-CoV-2 disease severity varies among different populations. Host genetics have been associated with various diseases, and their ability to alter disease susceptibility and severity. In addition, Human Leukocyte Antigen ( HLA ) expression levels and alleles vary significantly among ethnic groups, which might impact the host's response to SARS-CoV-2. Our previous study highlighted that HLA-A might have an effect on COVID-19 disease severity across ethnicities. Therefore, in this study, we aim to examine the effect of HLA-B and C expression levels on COVID-19 disease severity. To achieve this, we used real-time PCR to measure the HLA mRNA expression levels of SARS-CoV-2-infected individuals from a South African cohort and compared them across ethnic groups, disease outcomes, gender, comorbidities, and age. Our results show (1) that the effect of HLA-B mRNA expression levels was associated with differences in disease severity when we compare symptomatic vs. asymptomatic ( p < 0.0001). While HLA-C mRNA expression levels were not associated with COVID-19 disease severity. (2) In addition, we observed that HLA-B and HLA-C mRNA expression levels were significantly different between South African Black individuals and South African Indian individuals ( p < 0.0001, p < 0.0001). HLA-B mRNA expression levels among symptomatic South African Black individuals were significantly higher than symptomatic South African Indian individuals ( p < 0.0001). In addition, the HLA-B mRNA expression levels of symptomatic South African Black individuals were significantly higher than asymptomatic South African Black individuals ( p > 0.0001). HLA-C mRNA expression levels among symptomatic South African Black individuals were significantly higher than among symptomatic South African Indian individuals ( p = 0.0217). (3) HLA-C expression levels were significantly different between males and females ( p = 0.0052). In addition, the HLA-C expression levels of asymptomatic males are higher than asymptomatic females ( p = 0.0375). (4) HLA-B expression levels were significantly different between individuals with and without comorbidities ( p = 0.0009). In addition, we observed a significant difference between individuals with no comorbidities and non-communicable diseases ( p = 0.0034), in particular, hypertension ( p = 0.0487). (5) HLA-B expression levels were significantly different between individuals between 26-35 and 56-65 years ( p = 0.0380). Our work is expected to strengthen the understanding of the relationship between HLA and COVID-19 by providing insights into HLA-B and C expression levels across ethnic populations in South Africa among COVID-19-symptomatic and asymptomatic individuals. Our results highlight that HLA-B mRNA expression levels contribute to COVID-19 severity as well as variation in ethnicities associated with COVID-19. Further studies are needed to examine the effect of HLA expression levels across various ethnic groups with contributing factors.
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- 2024
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21. Narrative Review Explaining the Role of HLA-A , -B , and -C Molecules in COVID-19 Disease in and around Africa.
- Author
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Naidoo L, Arumugam T, and Ramsuran V
- Abstract
The coronavirus disease 2019 (COVID-19) has left a devasting effect on various regions globally. Africa has exceptionally high rates of other infectious diseases, such as tuberculosis (TB), human immunodeficiency virus (HIV), and malaria, and was not impacted by COVID-19 to the extent of other continents Globally, COVID-19 has caused approximately 7 million deaths and 700 million infections thus far. COVID-19 disease severity and susceptibility vary among individuals and populations, which could be attributed to various factors, including the viral strain, host genetics, environment, lifespan, and co-existing conditions. Host genetics play a substantial part in COVID-19 disease severity among individuals. Human leukocyte antigen (HLA) was previously been shown to be very important across host immune responses against viruses. HLA has been a widely studied gene region for various disease associations that have been identified. HLA proteins present peptides to the cytotoxic lymphocytes, which causes an immune response to kill infected cells. The HLA molecule serves as the central region for infectious disease association; therefore, we expect HLA disease association with COVID-19. Therefore, in this narrative review, we look at the HLA gene region, particularly, HLA class I, to understand its role in COVID-19 disease.
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- 2024
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22. Effects of Intranasal Dantrolene Nanoparticles on Brain Concentration and Behavior in PS19 Tau Transgenic Mice.
- Author
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Vera R, Hong N, Jiang B, Liang G, Eckenhoff MF, Kincaid HJ, Browne V, Chellaraj V, Gisewhite D, Greenberg M, Ranjan S, Zhu G, and Wei H
- Subjects
- Mice, Animals, Mice, Transgenic, Dantrolene pharmacology, Administration, Intranasal, Acrolein, Mice, Inbred C57BL, Brain metabolism, tau Proteins metabolism, Disease Models, Animal, Alzheimer Disease drug therapy, Tauopathies drug therapy
- Abstract
Background: Repurposing dantrolene to treat Alzheimer's disease has been shown to be effective in amyloid transgenic mouse models but has not been examined in a model of tauopathy., Objective: The effects of a nanoparticle intranasal formulation, the Eagle Research Formulation of Ryanodex (ERFR), in young adult and aged wild type and PS19 tau transgenic mice was investigated., Methods: The bioavailability of intranasal ERFR was measured in 2 and 9-11-month-old C57BL/6J mice. Blood and brain samples were collected 20 minutes after a single ERFR dose, and the plasma and brain concentrations were analyzed. Baseline behavior was assessed in untreated PS19 tau transgenic mice at 6 and 9 months of age. PS19 mice were treated with intranasal ERFR, with or without acrolein (to potentiate cognitive dysfunction), for 3 months, beginning at 2 months of age. Animal behavior was examined, including cognition (cued and contextual fear conditioning, y-maze), motor function (rotarod), and olfaction (buried food test)., Results: The dantrolene concentration in the blood and brain decreased with age, with the decrease greater in the blood resulting in a higher brain to blood concentration ratio. The behavioral assays showed no significant changes in cognition, olfaction, or motor function in the PS19 mice compared to controls after chronic treatment with intranasal ERFR, even with acrolein., Conclusions: Our studies suggest the intranasal administration of ERFR has higher concentrations in the brain than the blood in aged mice and has no serious systemic side effects with chronic use in PS19 mice.
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- 2024
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23. Host Genetic Impact on Infectious Diseases among Different Ethnic Groups.
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Naidoo L, Arumugam T, and Ramsuran V
- Abstract
Infectious diseases such as malaria, tuberculosis (TB), human immunodeficiency virus (HIV), and the coronavirus disease of 2019 (COVID-19) are problematic globally, with high prevalence particularly in Africa, attributing to most of the death rates. There have been immense efforts toward developing effective preventative and therapeutic strategies for these pathogens globally, however, some remain uncured. Disease susceptibility and progression for malaria, TB, HIV, and COVID-19 vary among individuals and are attributed to precautionary measures, environment, host, and pathogen genetics. While studying individuals with similar attributes, it is suggested that host genetics contributes to most of an individual's susceptibility to disease. Several host genes are identified to associate with these pathogens. Interestingly, many of these genes and polymorphisms are common across diseases. This paper analyzes genes and genetic variations within host genes associated with HIV, TB, malaria, and COVID-19 among different ethnic groups. The differences in host-pathogen interaction among these groups, particularly of Caucasian and African descent, and which gene polymorphisms are prevalent in an African population that possesses protection or risk to disease are reviewed. The information in this review could potentially help develop personalized treatment that could effectively combat the high disease burden in Africa., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. Advanced Genetics published by Wiley Periodicals LLC.)
- Published
- 2023
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24. The association of host genes with specific sexually transmitted infections.
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Bovungana Q, Arumugam T, and Ramsuran V
- Abstract
Sexually transmitted infections (STIs) are hazardous to human health worldwide. STIs have a direct influence on sexual and reproductive health and can increase the chances of HIV. Globally, more than 1 million STIs are acquired every day and the majority are asymptomatic. Approximately, 374 million cases of STIs have been reported annually. The most prevalent STIs include chlamydia, gonorrhoea, syphilis, and trichomoniasis. These STIs are caused by Chlamydia trachomatis , Neisseria gonorrhoeae , Treponema pallidum and Trichomonas vaginalis. The major factor that contributes to the susceptibility and prognosis of infectious diseases is genetic variation. Host genes play a huge role in STIs and immune response. The production of host factors is stimulated by a variety of bacteria, viruses and parasites and the host factors can play a role in increasing host vulnerability to infection and pathogen persistence. Genetic variation or polymorphisms within certain host genes can influence the course of pathogen infection and disease progression. Polymorphisms can contribute to changes in gene expression and or changes in the protein structure. which may either contribute to/or protect against infection. This review discusses the role of host genes in influencing the susceptibility of the most prevalent STIs caused by Chlamydia trachomatis , Trichomonas vaginalis, Treponema pallidum and Neisseria gonorrhoeae . We evaluate polymorphisms associated pathogen recognition signalling pathway of these diseases. These polymorphisms may be used as biomarkers to infer risk to specific STIs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Bovungana, Arumugam and Ramsuran.)
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- 2023
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25. Polymorphisms within the SARS-CoV-2 Human Receptor Genes Associate with Variable Disease Outcomes across Ethnicities.
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Adimulam T, Arumugam T, Naidoo A, Naidoo K, and Ramsuran V
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- Humans, Ethnicity genetics, Angiotensin-Converting Enzyme 2 genetics, Peptidyl-Dipeptidase A genetics, Peptidyl-Dipeptidase A metabolism, South Africa epidemiology, SARS-CoV-2 genetics, SARS-CoV-2 metabolism, COVID-19 genetics
- Abstract
The contribution of human genes to the variability of disease outcomes has been shown to be important across infectious diseases. Studies have shown mutations within specific human genes are associated with variable COVID-19 outcomes. We focused on the SARS-CoV-2 receptors/co-receptors to identify the role of specific polymorphisms within ACE2 , TMPRSS2 , NRP1 and CD147 . Polymorphisms within ACE2 (rs2285666), TMPRSS2 (rs12329760), CD147 (rs8259) and NRP1 (rs10080) have been shown to associate with COVID-19 severity. Using cryopreserved samples from COVID-19-positive African, European and South Asian individuals within South Africa, we determined genotype frequencies. The genetic variant rs2285666 was associated with COVID-19 severity with an ethnic bias. African individuals with a CC genotype demonstrate more severe COVID-19 outcomes (OR = 7.5; 95% CI 1.164-80.89; p = 0.024) compared with those with a TT genotype. The expressions of ACE2 and SARS-CoV-2 viral load were measured using droplet digital PCR. Our results demonstrate rs2285666 and rs10080 were significantly associated with increased SARS-CoV-2 viral load and worse outcomes in certain ethnicities. This study demonstrates two important findings. Firstly, SARS-CoV-2 viral load is significantly lower in Africans compared with individuals of European and South Asian descent ( p = 0.0002 and p < 0.0001). Secondly, SARS-CoV-2 viral load associates with specific SARS-CoV-2 receptor variants. A limited number of studies have examined the receptor/co-receptor genes within Africa. This study investigated genetic variants within the SARS-CoV-2 receptor/co-receptor genes and their association with COVID-19 severity and SARS-CoV-2 viral load across different ethnicities. We provide a genetic basis for differences in COVID-19 severity across ethnic groups in South Africa, further highlighting the importance of further investigation to determine potential therapeutic targets and to guide vaccination strategies that may prioritize specific genotypes.
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- 2023
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26. Single-nucleotide polymorphisms in ABC drug transporters alter expression and circulating tenofovir in healthy South African women exposed to pre-exposure prophylaxis.
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Zondo NM, Sobia P, Sivro A, Ngcapu S, Mansoor LE, Mahomed S, Lewis L, Ramsuran V, and Archary D
- Subjects
- Humans, Female, Tenofovir therapeutic use, Polymorphism, Single Nucleotide genetics, ATP-Binding Cassette Transporters genetics, South Africa, RNA, Messenger, HIV Infections drug therapy, HIV Infections genetics, HIV Infections prevention & control, Pre-Exposure Prophylaxis, Anti-HIV Agents therapeutic use
- Abstract
Aim: We investigated if single-nucleotide polymorphisms (SNPs) in ATP-binding cassette (ABC) drug transporters alter gene expression and tenofovir disposition in South African women taking Truvada
® for HIV prevention. Materials & methods: In 393 women, real-time PCR was used to determine the associations between six SNPs in ABC transporter genes, mRNA expression and circulating-tenofovir. Results: Univariable and multivariable analyses showed that CT and TT relative to CC genotypes for the ABCC4 (3463C/T) SNP had significantly higher tenofovir levels. In contrast, the AA genotype for the ABCC4 (4976A/G) SNP showed significantly less tenofovir, while mRNA expression was increased. Conclusion: SNPs in the ABCC4 gene may differentially affect gene expression and circulating tenofovir. Their impact may inform on low pre-exposure prophylaxis efficacy and discern effective drugs in clinical trials of African women enriched for certain genotypes.- Published
- 2023
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27. Comparison between qPCR and RNA-seq reveals challenges of quantifying HLA expression.
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Aguiar VRC, Castelli EC, Single RM, Bashirova A, Ramsuran V, Kulkarni S, Augusto DG, Martin MP, Gutierrez-Arcelus M, Carrington M, and Meyer D
- Subjects
- Humans, RNA-Seq, HLA-C Antigens genetics, Polymerase Chain Reaction, Genome-Wide Association Study, Histocompatibility Antigens Class I genetics
- Abstract
Human leukocyte antigen (HLA) class I and II loci are essential elements of innate and acquired immunity. Their functions include antigen presentation to T cells leading to cellular and humoral immune responses, and modulation of NK cells. Their exceptional influence on disease outcome has now been made clear by genome-wide association studies. The exons encoding the peptide-binding groove have been the main focus for determining HLA effects on disease susceptibility/pathogenesis. However, HLA expression levels have also been implicated in disease outcome, adding another dimension to the extreme diversity of HLA that impacts variability in immune responses across individuals. To estimate HLA expression, immunogenetic studies traditionally rely on quantitative PCR (qPCR). Adoption of alternative high-throughput technologies such as RNA-seq has been hampered by technical issues due to the extreme polymorphism at HLA genes. Recently, however, multiple bioinformatic methods have been developed to accurately estimate HLA expression from RNA-seq data. This opens an exciting opportunity to quantify HLA expression in large datasets but also brings questions on whether RNA-seq results are comparable to those by qPCR. In this study, we analyze three classes of expression data for HLA class I genes for a matched set of individuals: (a) RNA-seq, (b) qPCR, and (c) cell surface HLA-C expression. We observed a moderate correlation between expression estimates from qPCR and RNA-seq for HLA-A, -B, and -C (0.2 ≤ rho ≤ 0.53). We discuss technical and biological factors which need to be accounted for when comparing quantifications for different molecular phenotypes or using different techniques., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2023
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28. Intraductal papillary mucinous neoplasm of the intrahepatic bile duct: a review of literature and a rare case report.
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Zibari L, Naseer MS, Patel H, Shokouh-Amiri H, Wellman G, Dies D, Browne V, and Zibari GB
- Abstract
Background: Intraductal papillary neoplasm of the bile duct is a rare variant of bile duct tumors, which is characterized by papillary or villous growth inside the bile duct. Having papillary and mucinous features such as those found in pancreatic intraductal papillary mucinous neoplasm (IPMN) is extremely rare. We report a rare case of intraductal papillary mucinous neoplasm of the intrahepatic bile duct., Case Report: A 65-year-old male Caucasian with multiple comorbidities presented to the emergency room with moderate constant pain at the right upper quadrant (RUQ) abdomen for the last several hours. On physical examination, he was found to have normal vital signs, with icteric sclera and pain on deep palpation at the RUQ region. His laboratory results were significant for jaundice, elevated liver function tests and creatinine, hyperglycemia, and leukocytosis. Multiple imaging studies revealed a 5 cm heterogeneous mass in the left hepatic lobe that demonstrated areas of internal enhancement, mild gall bladder wall edema, dilated gall bladder with mild sludge, and 9 mm common bile duct (CBD) dilatation without evidence of choledocholithiasis. He underwent a CT-guided biopsy of this mass, which revealed intrahepatic papillary mucinous neoplasm. This case was discussed at the hepatobiliary multidisciplinary conference, and the patient underwent an uneventful robotic left partial liver resection, cholecystectomy, and lymphadenectomy., Conclusion: IPMN of the biliary tract may represent a carcinogenesis pathway different from that of CBD carcinoma arising from flat dysplasia. Complete surgical resection should be performed whenever possible because of its significant risk of harboring invasive carcinoma., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Zibari, Naseer, Patel, Shokouh-Amiri, Wellman, Dies, Browne and Zibari.)
- Published
- 2023
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29. Genetic Variants within SARS-CoV-2 Human Receptor Genes May Contribute to Variable Disease Outcomes in Different Ethnicities.
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Adimulam T, Arumugam T, Gokul A, and Ramsuran V
- Subjects
- Humans, Angiotensin-Converting Enzyme 2 genetics, Disease Susceptibility, Ethnicity, SARS-CoV-2 genetics, COVID-19 genetics
- Abstract
The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into a global pandemic, with an alarming infectivity and mortality rate. Studies have examined genetic effects on SARS-CoV-2 disease susceptibility and severity within Eurasian populations. These studies identified contrasting effects on the severity of disease between African populations. Genetic factors can explain some of the diversity observed within SARS-CoV-2 disease susceptibility and severity. Single nucleotide polymorphisms (SNPs) within the SARS-CoV-2 receptor genes have demonstrated detrimental and protective effects across ethnic groups. For example, the TT genotype of rs2285666 (Angiotensin-converting enzyme 2 (ACE2)) is associated with the severity of SARS-CoV-2 disease, which is found at higher frequency within Asian individuals compared to African and European individuals. In this study, we examined four SARS-CoV-2 receptors, ACE2, Transmembrane serine protease 2 (TMPRSS2), Neuropilin-1 (NRP1), and Basigin (CD147). A total of 42 SNPs located within the four receptors were reviewed: ACE2 (12), TMPRSS2 (10), BSG ( CD147 ) (5), and NRP1 (15). These SNPs may be determining factors for the decreased disease severity observed within African individuals. Furthermore, we highlight the absence of genetic studies within the African population and emphasize the importance of further research. This review provides a comprehensive summary of specific variants within the SARS-CoV-2 receptor genes, which can offer a better understanding of the pathology of the SARS-CoV-2 pandemic and identify novel potential therapeutic targets.
- Published
- 2023
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30. Effects of intranasal dantrolene nanoparticles on brain concentration and behavior in PS19 tau transgenic mice.
- Author
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Vera R, Hong N, Jiang B, Liang G, Eckenhoff MF, Kincaid HJ, Browne V, Chellaraj V, Gisewhite D, Greenberg M, Ranjan S, Zhu G, and Wei H
- Abstract
Background: Repurposing dantrolene as a potential disease-modifying treatment for Alzheimer's disease has been shown to be effective in amyloid transgenic mouse models but has not been examined in a model of tauopathy., Objective: The effects of a nanoparticle intranasal formulation, the Eagle Research Formulation of Ryanodex (ERFR), in young adult and aged wild type and PS19 tau transgenic mice was investigated., Methods: The bioavailability of intranasal ERFR was measured in 2 months and 9-12 month old C57BL/6J male mice. Mice received a single intranasal dose of ERFR and, after 20 min, blood and brain samples were collected. Dantrolene concentrations in the plasma and brain were analyzed by High Performance Liquid Chromatography. Animal behavior was examined in PS19 tau transgenic mice, with/without acrolein treatment to exacerbate cognitive deficits. Behavioral tests included cognition (cued and contextual fear conditioning, y-maze), motor function (rotarod), and olfaction (buried food test)., Results: Dantrolene concentration in the blood and brain decreased with age, though the decrease was greater in the blood resulting in a higher brain to blood concentration ratio. The behavioral assays showed no significant changes in cognition, olfaction or motor function in the PS19 mice compared to controls after chronic ERFR treatment even with acrolein treatment., Conclusion: Our studies suggest that while we did not find PS19 mice to be a reliable Alzheimer animal model to test the therapeutic efficacy of dantrolene, the results suggest a potential for ERFR to be an effective chronic therapy for Alzheimer's disease and that further studies are indicated., Competing Interests: Conflict of Interest Drs. Huafeng Wei, Maryellen Eckenhoff and Ge Liang are listed as inventors of patent application entitled “Intranasal Administration of Dantrolene for Treatment of Alzheimer’s Disease” in multiple countries by The Trustees of the University of Pennsylvania. Drs. Veron Browne, Vinolia Chellaraj, Douglas Gisewhite, Michael Greenberg, Sudhir Ranjan, and Gaozhong Zhu own stock options in Eagle Pharmaceuticals along with patents/royalties of the ryanodex drug used in this study. They are all full-time employees of Eagle Pharmaceuticals. All other authors have no conflicts of interest.
- Published
- 2023
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31. A Systematic Review of the Heterogenous Gene Expression Patterns Associated with Multidrug Chemoresistance in Conventional Osteosarcoma.
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Mthethwa PG, Marais LC, Ramsuran V, and Aldous CM
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- Animals, Humans, Drug Resistance, Neoplasm genetics, Drug Resistance, Multiple genetics, Gene Expression, Tumor Microenvironment, Osteosarcoma drug therapy, Osteosarcoma genetics, Bone Neoplasms drug therapy, Bone Neoplasms genetics
- Abstract
Multidrug chemoresistance (MDR) remains the most significant obstacle to improving survival in osteosarcoma patients. Heterogeneous genetic alterations characterise the tumour microenvironment, and host molecular markers have been associated with MDR. This systematic review examines the genetic alterations of molecular biomarkers associated with multidrug chemotherapy resistance in genome-wide analysis of central high-grade conventional osteosarcoma (COS). We systematically searched MEDLINE, EMBASE, Web of Science, Wiley online library and Scopus. Only human studies involving genome-wide analysis were included, while candidate gene, in vitro and animal studies were excluded. The risk of bias of the studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. The systematic search identified 1355 records. Following the screening, six studies were included in the qualitative analysis. There were 473 differentially expressed genes (DEGs) associated with chemotherapy response in COS. Fifty-seven of those were associated with MDR in osteosarcoma. The heterogeneous gene expressions were related to the mechanism of MDR in osteosarcoma. The mechanisms include drug-related sensitivity genes, bone remodelling and signal transduction. Complex, variable and heterogenous gene expression patterns underpin MDR in osteosarcoma. Further research is needed to identify the most relevant alterations for prognostication and to guide the development of possible therapeutic targets.
- Published
- 2023
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32. Genetic Ethnic Differences in Human 2'-5'-Oligoadenylate Synthetase and Disease Associations: A Systematic Review.
- Author
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Gokul A, Arumugam T, and Ramsuran V
- Subjects
- Humans, Adenine Nucleotides, Oligoribonucleotides, SARS-CoV-2, COVID-19
- Abstract
Recently, several studies have highlighted a skewed prevalence of infectious diseases within the African continent. Furthermore, a growing number of studies have demonstrated unique genetic variants found within the African genome are one of the contributing factors to the disease severity of infectious diseases within Africa. Understanding the host genetic mechanisms that offer protection against infectious diseases provides an opportunity to develop unique therapeutic interventions. Over the past two decades, several studies have linked the 2'-5'-oligoadenylate synthetase (OAS) family with a range of infectious diseases. More recently, the OAS-1 gene has also been associated with disease severity caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which led to a global pandemic. The OAS family serves as an antiviral factor through the interaction with Ribonuclease-Latent (RNase-L). This review explores the genetic variants observed within the OAS genes and the associations with various viral infections and how previously reported ethnic-specific polymorphisms drive clinical significance. This review provides an overview of OAS genetic association studies with a particular focus on viral diseases affecting individuals of African descent.
- Published
- 2023
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33. Slow progression of pediatric HIV associates with early CD8+ T cell PD-1 expression and a stem-like phenotype.
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Vieira V, Lim N, Singh A, Leitman E, Dsouza R, Adland E, Muenchhoff M, Roider J, Marin Lopez M, Carabelli J, Giandhari J, Groll A, Jooste P, Prado JG, Thobakgale C, Dong K, Kiepiela P, Prendergast AJ, Tudor-Williams G, Frater J, Walker BD, Ndung'u T, Ramsuran V, Leslie A, Kløverpris HN, and Goulder P
- Subjects
- Humans, CD4-Positive T-Lymphocytes, CD8-Positive T-Lymphocytes, Phenotype, HIV Infections, Programmed Cell Death 1 Receptor metabolism
- Abstract
HIV nonprogression despite persistent viremia is rare among adults who are naive to antiretroviral therapy (ART) but relatively common among ART-naive children. Previous studies indicate that ART-naive pediatric slow progressors (PSPs) adopt immune evasion strategies similar to those described in natural hosts of SIV. However, the mechanisms underlying this immunophenotype are not well understood. In a cohort of early-treated infants who underwent analytical treatment interruption (ATI) after 12 months of ART, expression of PD-1 on CD8+ T cells immediately before ATI was the main predictor of slow progression during ATI. PD-1+CD8+ T cell frequency was also negatively correlated with CCR5 and HLA-DR expression on CD4+ T cells and predicted stronger HIV-specific T lymphocyte responses. In the CD8+ T cell compartment of PSPs, we identified an enrichment of stem-like TCF-1+PD-1+ memory cells, whereas pediatric progressors and viremic adults had a terminally exhausted PD-1+CD39+ population. TCF-1+PD-1+ expression on CD8+ T cells was associated with higher proliferative activity and stronger Gag-specific effector functionality. These data prompted the hypothesis that the proliferative burst potential of stem-like HIV-specific cytotoxic cells could be exploited in therapeutic strategies to boost the antiviral response and facilitate remission in infants who received early ART with a preserved and nonexhausted T cell compartment.
- Published
- 2023
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34. Fasting/refeeding: an experimental model to study the impact of early thermal manipulation on hepatic metabolism in mule ducks.
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Andrieux C, Marchand M, Larroquet L, Veron V, Biasutti S, Barrieu J, Morganx P, Morisson M, Coustham V, Panserat S, and Houssier M
- Subjects
- Animals, Liver metabolism, Fasting, Models, Theoretical, Ducks metabolism, Fatty Liver genetics
- Abstract
An increase in egg incubation temperature was previously shown to enhance the metabolism of mule ducks and increase liver fattening after overfeeding, through a metabolic programming mechanism. Here, we examined whether fasting (F) followed by refeeding (RF) in 11-wk-old mule ducks could become an accelerated model to study the mechanisms of metabolic programming following embryonic thermal manipulation. This study investigated the hepatic response of mule ducks subjected to 23 h of fasting and 1 h of refeeding, in control or thermally programmed animals (with an increase of 1°C, 16 h per day from days 13 to 27 of embryogenesis). Liver weight and energy composition, hepatocyte structure, plasma parameters, and gene expression levels were measured at 1, 2, and 4 h after RF. All these parameters were strongly affected by RF, whereas significant impacts of embryonic programming were measured in cell size (+1 µm on average), lipid composition (+4.2% of saturated fatty acids 4 h after the meal), and relative gene expressions (including HK1 , SCD1 , ELOVL6 , and FASN ). In addition to confirming previously identified molecular targets of thermal manipulation, this study revealed new ones, thanks to kinetic sampling after RF. Finally, the detailed description of the impact of the F/RF challenge on the liver structure, composition, and gene expression, but also on plasma parameters allowed us to draw a parallel with these same traits measured during overfeeding. This comparative analysis suggests that this protocol could become a pertinent model to study the mechanisms involved in embryonic liver thermal programming, without overfeeding.
- Published
- 2023
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35. Evaluation of Various Alternative Economical and High Throughput SARS-CoV-2 Testing Methods within Resource-Limited Settings.
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Duma Z, Ramsuran V, Chuturgoon AA, Edward VA, Naidoo P, and Mkhize-Kwitshana ZL
- Subjects
- Humans, COVID-19 Testing, Laboratories, Real-Time Polymerase Chain Reaction, SARS-CoV-2 genetics, COVID-19 diagnosis
- Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak posed a challenge for diagnostic laboratories worldwide, with low-middle income countries (LMICs) being the most affected. The polymerase chain reaction (PCR) is the gold standard method for detecting SARS-CoV-2 infection. However, the challenge with this method is that it is expensive, which has resulted in under-testing for SARS-CoV-2 infection in many LMICs. Hence, this study aimed to compare and evaluate alternative methods for the mass testing of SARS-CoV-2 infection in laboratories with limited resources to identify cost-effective, faster, and accurate alternatives to the internationally approved kits. A total of 50 residual nasopharyngeal swab samples were used for evaluation and comparison between internationally approved kits (Thermo Fisher PureLink™ RNA Isolation Kit and Thermo Fisher TaqPath™ COVID-19 Assay Kit) and alternative methods (three RNA extraction and four commercial SARS-CoV-2 RT-PCR assay kits) in terms of the cost analysis, diagnostic accuracy, and turnaround time. In terms of performance, all of the alternative RNA extraction methods evaluated were comparable to the internationally approved kits but were more cost-effective (Lucigen QuickExtract™ RNA Extraction Kit, Bosphore EX-Tract Dry Swab RNA Solution and Sonicator method) and four commercial SARS-CoV-2 RT-PCR assay kits (Nucleic Acid COVID-19 Test Kit (SARS-CoV-2), abTES
TM COVID-19 qPCR I Kit, PCL COVID19 Speedy RT-PCR Kit, and PCLMD nCoV One-Step RT-PCR Kit) with a sensitivity range of 76-100% and specificity of 96-100%. The cost per sample was reduced by more than 50% when compared to internationally approved kits. When compared to the Thermo Fisher PureLink™ Kit and Thermo Fisher TaqPath™ COVID-19 Assay Kit, the alternative methods had a faster turnaround time, indicating that laboratories with limited resources may be able to process more samples in a day. The above-mentioned cost-effective, fast, and accurate evaluated alternative methods can be used in routine diagnostic laboratories with limited resources for mass testing for SARS-CoV-2 because these were comparable to the internationally approved kits, Thermo Fisher PureLink™ Kit and Thermo Fisher TaqPath™ COVID-19 Assay Kit. The implementation of alternative methods will be the most cost-effective option for testing SARS-CoV-2 infection in LMICs.- Published
- 2022
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36. Editorial: Epigenetics of infectious diseases.
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Kulkarni S, Arumugam T, Chuturgoon A, An P, and Ramsuran V
- Subjects
- Humans, Epigenesis, Genetic, Epigenomics, Communicable Diseases genetics
- Abstract
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Published
- 2022
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37. Assessment of Antibiotic Resistance and Efflux Pump Gene Expression in Neisseria Gonorrhoeae Isolates from South Africa by Quantitative Real-Time PCR and Regression Analysis.
- Author
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Mitchev N, Singh R, Ramsuran V, Ismail A, Allam M, Kwenda S, Mnyameni F, Garrett N, Swe Swe-Han K, Niehaus AJ, and Mlisana KP
- Abstract
Introduction: Treatment of gonorrhoea infection is limited by the increasing prevalence of multidrug-resistant strains. Cost-effective molecular diagnostic tests can guide effective antimicrobial stewardship. The aim of this study was to correlate mRNA expression levels in Neisseria gonorrhoeae antibiotic target genes and efflux pump genes to antibiotic resistance in our population., Methods: This study investigated the expression profile of antibiotic resistance-associated genes ( penA , ponA , pilQ , mtrR , mtrA , mtrF , gyrA , parC , parE , rpsJ , 16S rRNA , and 23S rRNA ) and efflux pump genes ( macAB , norM, and mtrCDE ), by quantitative real-time PCR, in clinical isolates from KwaZulu-Natal, South Africa. Whole-genome sequencing was used to determine the presence or absence of mutations., Results: N. gonorrhoeae isolates, from female and male patients presenting for care at clinics in KwaZulu-Natal, South Africa, were analysed. As determined by binomial regression and ROC analysis, the most significant ( p ≤ 0.05) markers for resistance prediction in this population, and their cutoff values, were determined to be mtrC ( p = 0.024; cutoff <0.089), gyrA ( p = 0.027; cutoff <0.0518) , parE ( p = 0.036; cutoff <0.0033) , rpsJ ( p = 0.047; cutoff <0.0012), and 23S rRNA ( p = 0.042; cutoff >7.754)., Conclusion: Antimicrobial stewardship includes exploring options to conserve currently available drugs for gonorrhoea treatment. There is the potential to predict an isolate as either susceptible or nonsusceptible based on the mRNA expression level of specific candidate markers, to inform patient management. This real-time qPCR approach, with few targets, can be further investigated for use as a potentially cost-effective diagnostic tool to detect resistance., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Nireshni Mitchev et al.)
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- 2022
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38. Pharmacogenomics of drug transporters for antiretroviral long-acting pre-exposure prophylaxis for HIV.
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Zondo NM, Sobia P, Sivro A, Ngcapu S, Ramsuran V, and Archary D
- Abstract
The use of antiretrovirals (ARVs) as oral, topical, or long-acting pre-exposure prophylaxis (PrEP) has emerged as a promising strategy for HIV prevention. Clinical trials testing Truvada
® [tenofovir disoproxil fumarate (TDF)/tenofovir (TFV) and emtricitabine (FTC)] as oral or topical PrEP in African women showed mixed results in preventing HIV infections. Since oral and topical PrEP effectiveness is dependent on adequate drug delivery and availability to sites of HIV infection such as the blood and female genital tract (FGT); host biological factors such as drug transporters have been implicated as key regulators of PrEP. Drug transporter expression levels and function have been identified as critical determinants of PrEP efficacy by regulating PrEP pharmacokinetics across various cells and tissues of the blood, renal tissues, FGT mucosal tissues and other immune cells targeted by HIV. In addition, biological factors such as genetic polymorphisms and genital inflammation also influence drug transporter expression levels and functionality. In this review, drug transporters and biological factors modulating drug transporter disposition are used to explain discrepancies observed in PrEP clinical trials. This review also provides insight at a pharmacological level of how these factors further increase the susceptibility of the FGT to HIV infections, subsequently contributing to ineffective PrEP interventions in African women., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Zondo, Sobia, Sivro, Ngcapu, Ramsuran and Archary.)- Published
- 2022
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39. Genetic variation that determines TAPBP expression levels associates with the course of malaria in an HLA allotype-dependent manner.
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Walker-Sperling V, Digitale JC, Viard M, Martin MP, Bashirova A, Yuki Y, Ramsuran V, Kulkarni S, Naranbhai V, Li H, Anderson SK, Yum L, Clifford R, Kibuuka H, Ake J, Thomas R, Rowland-Jones S, Rek J, Arinaitwe E, Kamya M, Rodriguez-Barraquer I, Feeney ME, and Carrington M
- Subjects
- Binding Sites, Genetic Variation, Humans, MicroRNAs metabolism, Peptides immunology, RNA, Messenger genetics, Transcription Factor AP-2 metabolism, Histocompatibility Antigens Class I immunology, Malaria, Falciparum genetics, Malaria, Falciparum immunology, Malaria, Falciparum parasitology, Membrane Transport Proteins genetics, Membrane Transport Proteins metabolism, Plasmodium falciparum immunology
- Abstract
HLA class I (HLA-I) allotypes vary widely in their dependence on tapasin (TAPBP), an integral component of the peptide-loading complex, to present peptides on the cell surface. We identified two single-nucleotide polymorphisms that regulate TAPBP messenger RNA (mRNA) expression in Africans, rs111686073 ( G / C ) and rs59097151 (A / G) , located in an AP-2α transcription factor binding site and a microRNA (miR)-4486 binding site, respectively. rs111686073G and rs59097151A induced significantly higher TAPBP mRNA expression relative to the alternative alleles due to higher affinity for AP-2α and abrogation of miR-4486 binding, respectively. These variants associated with lower Plasmodium falciparum parasite prevalence and lower incidence of clinical malaria specifically among individuals carrying tapasin-dependent HLA-I allotypes, presumably by augmenting peptide loading, whereas tapasin-independent allotypes associated with relative protection, regardless of imputed TAPBP mRNA expression levels. Thus, an attenuated course of malaria may occur through enhanced breadth and/or magnitude of antigen presentation, an important consideration when evaluating vaccine efficacy.
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- 2022
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40. The Effect of miRNA Gene Regulation on HIV Disease.
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Chinniah R, Adimulam T, Nandlal L, Arumugam T, and Ramsuran V
- Abstract
Over many years, research on HIV/AIDS has advanced with the introduction of HAART. Despite these advancements, significant gaps remain with respect to aspects in HIV life cycle, with specific attention to virus-host interactions. Investigating virus-host interactions may lead to the implementation of novel therapeutic strategies against HIV/AIDS. Notably, host gene silencing can be facilitated by cellular small non-coding RNAs such as microRNAs paving the way for epigenetic anti-viral therapies. Numerous studies have elucidated the importance of microRNAs in HIV pathogenesis. Some microRNAs can either promote viral infection, while others can be detrimental to viral replication. This is accomplished by targeting the HIV-proviral genome or by regulating host genes required for viral replication and immune responses. In this review, we report on 1) the direct association of microRNAs with HIV infection; 2) the indirect association of known human genetic factors with HIV infection; 3) the regulation of human genes by microRNAs in other diseases that can be explored experimentally to determine their effect on HIV-1 infection; and 4) therapeutic interactions of microRNA against HIV infection., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chinniah, Adimulam, Nandlal, Arumugam and Ramsuran.)
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- 2022
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41. Hypermethylation at the CXCR5 gene locus limits trafficking potential of CD8+ T cells into B-cell follicles during HIV-1 infection.
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Ogunshola FJ, Smidt W, Naidoo AF, Nkosi T, Ngubane T, Khaba T, Baiyegunhi OO, Mahlobo B, Rasehlo S, Ngema N, Jajbhay I, Dong KL, Ramsuran V, Pansegrouw J, Ndung'u T, Walker BD, Oliveria T, and Ndhlovu ZM
- Subjects
- B-Lymphocytes metabolism, CD8-Positive T-Lymphocytes metabolism, Humans, Receptors, CXCR5 genetics, Receptors, CXCR5 metabolism, HIV Infections genetics, HIV-1
- Abstract
CD8+ T cells play an important role in HIV control. However, in human lymph nodes (LNs), only a small subset of CD8+ T cells express CXCR5, the chemokine receptor required for cell migration into B-cell follicles, which are major sanctuaries for HIV persistence in individuals on therapy. Here, we investigate the impact of HIV infection on follicular CD8+ T cell (fCD8) frequencies, trafficking patterns, and CXCR5 regulation. We show that, although HIV infection results in a marginal increase in fCD8s in LNs, the majority of HIV-specific CD8+ T cells are CXCR5- (non-fCD8s) (P < .003). Mechanistic investigations using Assay for Transposase-Accessible Chromatin using sequencing showed that non-fCD8s have closed chromatin at the CXCR5 transcriptional start site (TSS). DNA bisulfite sequencing identified DNA hypermethylation at the CXCR5 TSS as the most probable cause of closed chromatin. Transcriptional factor footprint analysis revealed enrichment of transforming growth factors (TGFs) at the TSS of fCD8s. In vitro stimulation of non-fCD8s with recombinant TGF-β resulted in a significant increase in CXCR5 expression (fCD8s). Thus, this study identifies TGF-β signaling as a viable strategy for increasing fCD8 frequencies in follicular areas of the LN where they are needed to eliminate HIV-infected cells, with implications for HIV cure strategies., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)
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- 2022
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42. The challenges of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing in low-middle income countries and possible cost-effective measures in resource-limited settings.
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Duma Z, Chuturgoon AA, Ramsuran V, Edward V, Naidoo P, Mpaka-Mbatha MN, Bhengu KN, Nembe N, Pillay R, Singh R, and Mkhize-Kwitshana ZL
- Subjects
- COVID-19 Testing, Cost-Benefit Analysis, Developing Countries, Humans, COVID-19, SARS-CoV-2
- Abstract
Diagnostic testing for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection remains a challenge around the world, especially in low-middle-income countries (LMICs) with poor socio-economic backgrounds. From the beginning of the pandemic in December 2019 to August 2021, a total of approximately 3.4 billion tests were performed globally. The majority of these tests were restricted to high income countries. Reagents for diagnostic testing became a premium, LMICs either cannot afford or find manufacturers unwilling to supply them with expensive analytical reagents and equipment. From March to December 2020 obtaining testing kits for SARS-CoV-2 testing was a challenge. As the number of SARS-CoV-2 infection cases increases globally, large-scale testing still remains a challenge in LMICs. The aim of this review paper is to compare the total number and frequencies of SARS-CoV-2 testing in LMICs and high-income countries (HICs) using publicly available data from Worldometer COVID-19, as well as discussing possible interventions and cost-effective measures to increase testing capability in LMICs. In summary, HICs conducted more SARS-CoV-2 testing (USA: 192%, Australia: 146%, Switzerland: 124% and Canada: 113%) compared to middle-income countries (MICs) (Vietnam: 43%, South Africa: 29%, Brazil: 27% and Venezuela: 12%) and low-income countries (LICs) (Bangladesh: 6%, Uganda: 4% and Nigeria: 1%). Some of the cost-effective solutions to counteract the aforementioned problems includes using saliva instead of oropharyngeal or nasopharyngeal swabs, sample pooling, and testing high-priority groups to increase the number of mass testing in LMICs., (© 2022. The Author(s).)
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- 2022
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43. High-Resolution Melting Analysis to Detect Antimicrobial Resistance Determinants in South African Neisseria gonorrhoeae Clinical Isolates and Specimens.
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Mitchev N, Singh R, Ramsuran V, Ismail A, Allam M, Kwenda S, Mnyameni F, Garrett N, Swe-Han KS, Niehaus AJ, and Mlisana KP
- Abstract
Background: Antimicrobial resistance is limiting treatment options for Neisseria gonorrhoeae infections. To aid or replace culture and the syndromic management approach, molecular assays are required for antimicrobial susceptibility testing to guide appropriate and rapid treatment., Objective: We aimed to detect single-nucleotide polymorphisms and plasmids associated with antimicrobial resistance from N. gonorrhoeae isolates from a clinic population in South Africa, using real-time PCR as a rapid test for AMR detection., Methods: N. gonorrhoeae isolates, from female and male patients presenting for care at a sexually transmitted infections clinic in Durban, South Africa, were analysed using phenotypic and genotypic methods for identification and antibiotic susceptibility testing (AST). Real-time PCR and high-resolution melting analysis were used to detect porA pseudogene (species-specific marker) and resistance-associated targets. Whole-genome sequencing was used as the gold standard for the presence of point mutations., Results: The real-time porA pseudogene assay identified all N. gonorrhoeae -positive isolates and specimens. Concordance between molecular detection (real-time PCR and HRM) and resistance phenotype was ≥92% for bla
TEM (HLR penicillin), rpsJ_V57M (tetracycline), tetM (tetracycline), and gyrA_S91F (ciprofloxacin). Resistance determinants 16SrRNA_C1192U (spectinomycin), mtrR_G45D (azithromycin), and penA_D545S, penA_mosaic (cefixime/ceftriaxone) correlated with the WHO control isolates., Conclusions: Eight resistance-associated targets correlated with phenotypic culture results. The porA pseudogene reliably detected N. gonorrhoeae . Larger cohorts are required to validate the utility of these targets as a convenient culture-free diagnostic tool, to guide STI management in a South African population., Competing Interests: The authors have no conflicts of interest., (Copyright © 2022 Nireshni Mitchev et al.)- Published
- 2022
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44. Deciphering DNA Methylation in HIV Infection.
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Arumugam T, Ramphal U, Adimulam T, Chinniah R, and Ramsuran V
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- Animals, Biomarkers, DNA Methylation, Epigenesis, Genetic, Humans, Genetic Therapy trends, HIV Infections genetics, HIV-1 physiology
- Abstract
With approximately 38 million people living with HIV/AIDS globally, and a further 1.5 million new global infections per year, it is imperative that we advance our understanding of all factors contributing to HIV infection. While most studies have focused on the influence of host genetic factors on HIV pathogenesis, epigenetic factors are gaining attention. Epigenetics involves alterations in gene expression without altering the DNA sequence. DNA methylation is a critical epigenetic mechanism that influences both viral and host factors. This review has five focal points, which examines (i) fluctuations in the expression of methylation modifying factors upon HIV infection (ii) the effect of DNA methylation on HIV viral genes and (iii) host genome (iv) inferences from other infectious and non-communicable diseases, we provide a list of HIV-associated host genes that are regulated by methylation in other disease models (v) the potential of DNA methylation as an epi-therapeutic strategy and biomarker. DNA methylation has also been shown to serve as a robust therapeutic strategy and precision medicine biomarker against diseases such as cancer and autoimmune conditions. Despite new drugs being discovered for HIV, drug resistance is a problem in high disease burden settings such as Sub-Saharan Africa. Furthermore, genetic therapies that are under investigation are irreversible and may have off target effects. Alternative therapies that are nongenetic are essential. In this review, we discuss the potential role of DNA methylation as a novel therapeutic intervention against HIV., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Arumugam, Ramphal, Adimulam, Chinniah and Ramsuran.)
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- 2021
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45. An HLA-I signature favouring KIR-educated Natural Killer cells mediates immune control of HIV in children and contrasts with the HLA-B-restricted CD8+ T-cell-mediated immune control in adults.
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Vieira VA, Adland E, Malone DFG, Martin MP, Groll A, Ansari MA, Garcia-Guerrero MC, Puertas MC, Muenchhoff M, Guash CF, Brander C, Martinez-Picado J, Bamford A, Tudor-Williams G, Ndung'u T, Walker BD, Ramsuran V, Frater J, Jooste P, Peppa D, Carrington M, and Goulder PJR
- Subjects
- Adolescent, Child, Child, Preschool, Cohort Studies, HIV Infections metabolism, HIV Infections virology, Humans, Lymphocyte Activation, CD8-Positive T-Lymphocytes immunology, HIV Infections immunology, HIV-1 immunology, HLA-B Antigens immunology, Histocompatibility Antigens Class I immunology, Killer Cells, Natural immunology, Receptors, KIR3DL1 metabolism
- Abstract
Natural Killer (NK) cells contribute to HIV control in adults, but HLA-B-mediated T-cell activity has a more substantial impact on disease outcome. However, the HLA-B molecules influencing immune control in adults have less impact on paediatric infection. To investigate the contribution NK cells make to immune control, we studied >300 children living with HIV followed over two decades in South Africa. In children, HLA-B alleles associated with adult protection or disease-susceptibility did not have significant effects, whereas Bw4 (p = 0.003) and low HLA-A expression (p = 0.002) alleles were strongly associated with immunological and viral control. In a comparator adult cohort, Bw4 and HLA-A expression contributions to HIV disease outcome were dwarfed by those of protective and disease-susceptible HLA-B molecules. We next investigated the immunophenotype and effector functions of NK cells in a subset of these children using flow cytometry. Slow progression and better plasma viraemic control were also associated with high frequencies of less terminally differentiated NKG2A+NKp46+CD56dim NK cells strongly responsive to cytokine stimulation and linked with the immunogenetic signature identified. Future studies are indicated to determine whether this signature associated with immune control in early life directly facilitates functional cure in children., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
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46. SARS-CoV-2 and helminth co-infections, and environmental pollution exposure: An epidemiological and immunological perspective.
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Naidoo P, Ghazi T, Chuturgoon AA, Naidoo RN, Ramsuran V, Mpaka-Mbatha MN, Bhengu KN, Nembe N, Duma Z, Pillay R, Singh R, and Mkhize-Kwitshana ZL
- Subjects
- Animals, Environmental Pollution, Humans, SARS-CoV-2, COVID-19, Coinfection, Helminths
- Abstract
Soil-transmitted helminths infect billions of people globally, particularly those residing in low- and middle-income regions with poor environmental sanitation and high levels of air and water pollution. Helminths display potent immunomodulatory activity by activating T helper type 2 (Th2) anti-inflammatory and Th3 regulatory immune responses. The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus that causes Coronavirus disease 2019 (COVID-19), can exacerbate Th1/Th17 pro-inflammatory cytokine production in humans, leading to a cytokine storm. Air pollutants (particulate matter, oxygen radicals, hydrocarbons and volatile organic compounds) and water pollutants (metals and organic chemicals) can also intensify Th1/Th17 immune response and could exacerbate SARS-CoV-2 related respiratory distress and failure. The present review focused on the epidemiology of SARS-CoV-2, helminths and fine particulate matter 2.5 µm or less in diameter (PM
2.5 ) air pollution exposure in helminth endemic regions, the possible immunomodulatory activity of helminths against SARS-CoV-2 hyper-inflammatory immune response, and whether air and water pollutants can further exacerbate SARS-CoV-2 related cytokine storm and in the process hinder helminths immunomodulatory functionality. Helminth Th2/Th3 immune response is associated with reductions in lung inflammation and damage, and decreased expression levels of angiotensin-converting enzyme 2 (ACE2) receptors (SARS-CoV-2 uses the ACE2 receptors to infect cells and associated with extensive lung damage). However, air pollutants are associated with overexpression of ACE2 receptors in the epithelial cell surface of the respiratory tract and exhaustion of Th2 immune response. Helminth-induced immunosuppression activity reduces vaccination efficacy, and diminishes vital Th1 cytokine production immune responses that are crucial for combating early stage infections. This could be reversed by continuous air pollution exposure which is known to intensify Th1 pro-inflammatory cytokine production to a point where the immunosuppressive activities of helminths could be hindered. Again, suppressed activities of helminths can also be disadvantageous against SARS-CoV-2 inflammatory response. This "yin and yang" approach seems complex and requires more understanding. Further studies are warranted in a cohort of SARS-CoV-2 infected individuals residing in helminths and air pollution endemic regions to offer more insights, and to impact mass periodic deworming programmes and environmental health policies., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2021
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47. Antimicrobial Resistance Mechanisms, Multilocus Sequence Typing, and NG-STAR Sequence Types of Diverse Neisseria gonorrhoeae Isolates in KwaZulu-Natal, South Africa.
- Author
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Mitchev N, Singh R, Allam M, Kwenda S, Ismail A, Garrett N, Ramsuran V, Niehaus AJ, and Mlisana KP
- Subjects
- Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Ceftriaxone, Drug Resistance, Bacterial genetics, Humans, Microbial Sensitivity Tests, Multilocus Sequence Typing, South Africa epidemiology, Gonorrhea drug therapy, Gonorrhea epidemiology, Neisseria gonorrhoeae genetics
- Abstract
Antimicrobial resistance (AMR) is a major challenge to managing infectious diseases. Africa has the highest incidence of gonorrhoea, but there is a lack of comprehensive data from sparse surveillance programs. This study investigated the molecular epidemiology and AMR profiles of Neisseria gonorrhoeae isolates in KwaZulu-Natal province (KZN), South Africa. Repository isolates from patients attending public health care clinics for sexually transmitted infection (STI) care were used for phenotypic and genotypic analysis. An Etest was performed to determine antimicrobial susceptibility. Whole-genome sequencing (WGS) was used to determine epidemiology and to predict susceptibility by detecting resistance-associated genes and mutations. Among the 61 isolates, multiple sequence types were identified. Six isolates were novel, as determined by multilocus sequence typing. N. gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) determined 48 sequence types, of which 35 isolates had novel antimicrobial profiles. Two novel penA alleles and eight novel mtrR alleles were identified. Point mutations were detected in gyrA , parC , mtrR , penA , ponA , and porB1 . This study revealed a high prevalence of AMR (penicillin 67%, tetracycline 89%, and ciprofloxacin 52%). However, spectinomycin, cefixime, ceftriaxone, and azithromycin remained 100% effective. This study is one of the first to comprehensively describe the epidemiology and AMR of N. gonorrhoeae in KZN, South Africa and Africa, using WGS. KZN has a wide strain diversity and most of these sequence types have been detected in multiple countries; however, more than half of our isolates have novel antimicrobial profiles. Continued surveillance is crucial to monitor the emergence of resistance to cefixime, ceftriaxone, and azithromycin.
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- 2021
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48. Strong correlation between urine and vaginal swab samples for bacterial vaginosis.
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Naicker D, Ramsuran V, Naicker M, Dessai F, Giandhari J, Tinarwo P, and Abbai N
- Abstract
Background: Vaginal swabs have been traditionally used for the diagnosis of bacterial vaginosis (BV). Currently, there are limited studies that have investigated the use of other sample types other than vaginal swabs for the detection of BV from South African populations. This study investigated whether urine can be used for the detection of BV-associated microorganisms in South African pregnant women., Methods: One-hundred self-collected vaginal swabs and urine samples were obtained from women presenting for antenatal care at King Edward VIII Hospital in Durban. The BD MAX™ vaginal panel assay was used for diagnosing BV and droplet digital polymerase chain reaction was used to quantify Gardnerella vaginalis, Prevotella bivia, Atopobium vaginae and Lactobacillus crispatus . The absolute counts were determined on the QX200 Droplet Reader (Bio-Rad) using the QuantaSoft Software. Data analysis was performed with statistical computing software called R, version 3.6.1., Results: Median copy numbers obtained for G. vaginalis and P. bivia across urine and swabs in BV-positive samples were not significantly different ( p = 0.134 and p = 0.652, respectively). This was confirmed by the correlation analysis that showed a good correlation between the two sample types ( G. vaginalis [ r = 0.63] and P. bivia [ r = 0.50]). However, the data obtained for A. vaginae differed, and a weak correlation between urine and swabs was observed ( r = 0.21). Bacterial vaginosis-negative samples had no significant difference in median copy numbers for L. crispatus across the urine and swabs ( p = 0.062), and a good correlation between the sample types was noted ( r = 0.71)., Conclusion: This study highlights the appropriateness of urine for the detection of microorganisms associated with BV., Competing Interests: The authors declare that they have no financial or personal relationships that may have inappropriately influenced them in writing this article., (© 2021. The Authors.)
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- 2021
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49. Transient association between semen exposure and biomarkers of genital inflammation in South African women at risk of HIV infection.
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Jewanraj J, Ngcapu S, Osman F, Ramsuran V, Fish M, Mtshali A, Singh R, Mansoor LE, Abdool Karim SS, Abdool Karim Q, Passmore JS, and Liebenberg LJP
- Subjects
- Biomarkers, Female, Humans, Inflammation diagnosis, Pregnancy, Semen, South Africa epidemiology, Vagina, HIV Infections diagnosis
- Abstract
Introduction: Semen induces mucosal changes in the female reproductive tract to improve pregnancy outcomes. Since semen-induced alterations are likely short-lived and genital inflammation is linked to HIV acquisition in women, we investigated the contribution of recent semen exposure on biomarkers of genital inflammation in women at high HIV risk and the persistence of these associations., Methods: We assessed stored genital specimens from 152 HIV-negative KwaZulu-Natal women who participated in the CAPRISA 008 trial between November 2012 and October 2014. During the two-year study period, 651 vaginal specimens were collected biannually (mean five samples per woman). Cervicovaginal lavage (CVL) was screened for prostate-specific antigen (PSA) by ELISA, whereas Y-chromosome DNA (YcDNA) detection and quantification were conducted by RT-PCR, representing semen exposure within 48 hours (PSA+YcDNA+) and semen exposure within three to fifteen days (PSA-YcDNA+). Soluble protein concentrations were measured in CVLs by multiplexed ELISA. T-cell frequencies were assessed in cytobrushes by flow-cytometry, and vulvovaginal swabs were used to detect common vaginal microbes by PCR. Linear mixed models adjusting for factors associated with genital inflammation and HIV risk were used to assess the impact of semen exposure on biomarkers of inflammation over multiple visits., Results: Here, 19% (125/651) of CVLs were PSA+YcDNA+, 14% (93/651) were PSA-YcDNA+ and 67% (433/651) were PSA-YcDNA-. Semen exposure was associated with how often women saw their partners, the frequency of vaginal sex in the past month, HSV-2 antibody detection, current gonorrhoea infection and Nugent Score. Both PSA detection (PSA+YcDNA+) and higher cervicovaginal YcDNA concentrations predicted increases in several cytokines, barrier-related proteins (MMP-2, TIMP-1 and TIMP-4) and activated CD4+CCR5+HLA-DR+ T cells (β = 0.050; CI 0.001 to 0.098; p = 0.046) and CD4+HLA-DR+ T cells (β = 0.177; CI 0.016 to 0.339; p = 0.032) respectively. PSA detection was specifically associated with raised pro-inflammatory cytokines (including IL-6, TNF-α, IP-10 and RANTES), and with the detection of BVAB2 (OR = 1.755; CI 1.116 to 2.760; p = 0.015), P. bivia (OR = 1.886; CI 1.102 to 3.228; p = 0.021) and Gardnerella vaginalis (OR = 1.815; CI 1.093 to 3.015; p = 0.021)., Conclusions: More recent semen exposure was associated with raised levels of inflammatory biomarkers and the detection of BV-associated microbes, which declined by three to fifteen days of post-exposure. Although transient, semen-induced alterations may have implications for HIV susceptibility in women., (© 2021 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of International AIDS Society.)
- Published
- 2021
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50. Epigenetic Regulation of BST-2 Expression Levels and the Effect on HIV-1 Pathogenesis.
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Singh R, Ramsuran V, Naranbhai V, Yende-Zuma N, Garrett N, Mlisana K, Dong KL, Walker BD, Abdool Karim SS, Carrington M, and Ndung'u T
- Subjects
- Antigens, CD blood, Black People genetics, Case-Control Studies, Cells, Cultured, Cross-Sectional Studies, Female, GPI-Linked Proteins blood, GPI-Linked Proteins genetics, HIV Infections ethnology, HIV Infections immunology, HIV-1 growth & development, HIV-1 immunology, Host-Pathogen Interactions, Humans, Leukocytes, Mononuclear immunology, Leukocytes, Mononuclear virology, Longitudinal Studies, Prognosis, South Africa epidemiology, Viral Load, Antigens, CD genetics, DNA Methylation, Epigenesis, Genetic, HIV Infections genetics, HIV Infections virology, HIV-1 pathogenicity, Virus Replication
- Abstract
HIV-1 must overcome host antiviral restriction factors for efficient replication. We hypothesized that elevated levels of bone marrow stromal cell antigen 2 ( BST-2 ), a potent host restriction factor that interferes with HIV-1 particle release in some human cells and is antagonized by the viral protein Vpu, may associate with viral control. Using cryopreserved samples, from HIV-1 seronegative and seropositive Black women, we measured in vitro expression levels of BST-2 mRNA using a real-time PCR assay and protein levels were validated by Western blotting. The expression level of BST-2 showed an association with viral control within two independent cohorts of Black HIV infected females (r=-0.53, p=0.015, [n =21]; and r=-0.62, p=0.0006, [n=28]). DNA methylation was identified as a mechanism regulating BST-2 levels, where increased BST-2 methylation results in lower expression levels and associates with worse HIV disease outcome. We further demonstrate the ability to regulate BST-2 levels using a DNA hypomethylation drug. Our results suggest BST-2 as a factor for potential therapeutic intervention against HIV and other diseases known to involve BST-2 ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling Editor declared a shared affiliation, though no other collaboration, with one of the authors [MC]., (Copyright © 2021 Singh, Ramsuran, Naranbhai, Yende-Zuma, Garrett, Mlisana, Dong, Walker, Abdool Karim, Carrington and Ndung’u.)
- Published
- 2021
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