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Delivery of messenger RNA (mRNA) by using lipid nanoparticles (LNPs) is expected to be applied to various diseases after the successful clinical use of the mRNA COVID-19 vaccines. This study aimed to evaluate the effect of the cholesterol molar percentage of mRNA-LNPs on protein expression in hepatocellular carcinoma-derived cells and in the liver after intramuscular or subcutaneous administration of mRNA-LNPs in mice. For mRNA-LNPs with cholesterol molar percentages reduced to 10 mol% and 20 mol%, we formulated neutral charge particles of approximately 100 nm diameter and polydispersity index (PDI)0.25. After the intramuscular or subcutaneous administration of mRNA-LNPs with different cholesterol molar percentages in mice, protein expression in the liver decreased as the cholesterol molar percentage in mRNA-LNPs decreased from 40 mol% to 20 mol% and 10 mol%, suggesting that reducing the cholesterol molar percentage in mRNA-LNPs decreases protein expression in the liver. Furthermore, in HepG2 cells, protein expression decreased as cholesterol in mRNA-LNPs was reduced by 40 mol%, 20 mol%, and 10 mol%. These results suggest that the downregulated expression of mRNA-LNPs with low cholesterol content in the liver involves degradation in systemic circulating blood and decreased protein expression after hepatocyte distribution.

Two phenylpropanoid conjugated iridoids, deglucosyl gaertneroside (1) and morindoidin (2), were isolated from the leaves of Morinda morindoides (Rubiaceae) by activity-guided fractionation using an anti-malarial activity assay. The known related iridoids molucidin (3) and prismatomerin (4), two lignans, abscisic acid, two megastigmanes, and two flavonol glycosides were also identified. The structures of isolated compounds were elucidated using spectroscopic analysis. The isolated compounds were evaluated for anti-malarial activity against the chloroquine/mefloquine-sensitive strains of Plasmodium falciparum together with cytotoxicity against adult mouse brain cells. Potent anti-malarial activity of 3 and 4 (IC50 of 0.96 and 0.80 μM, CC50 of 1.02 and 0.88 μM, and SI of 1.06 and 1.10 μM, respectively) was shown, while new iridoids 1 and 2 and pinoresinol (5) displayed moderate activity (IC50 of 40.9, 20.6, and 24.2 μM) without cytotoxicity (CC50 > 50 μM). These results indicate that 1–5 may be promising lead compounds for anti-malarial drugs. In addition, our results imply the necessity of the quality control of the extract of M. morindoides leaves based on the contents of 1–5 in terms of the safety and efficacy.

Background: Emergence of cross-resistance to current anti-malarial drugs has led to an urgent need for identification of potential compounds with novel modes of action and anti-malarial activity against the resistant strains. One of the most promising therapeutic targets of anti-malarial agents related to food vacuole of malaria parasite is haemozoin, a product formed by the parasite through haemoglobin degradation. Methods: With this in mind, this study developed two-dimensional-quantitative structure–activity relationships (QSAR) models of a series of 21 haemozoin inhibitors to explore the useful physicochemical parameters of the active compounds for estimation of anti-malarial activities. The 2D-QSAR model with good statistical quality using partial least square method was generated after removing the outliers. Results: Five two-dimensional descriptors of the training set were selected: atom count (a_ICM); adjacency and distance matrix descriptor (GCUT_SLOGP_2: the third GCUT descriptor using atomic contribution to logP); average total charge sum (h_pavgQ) in pKa prediction (pH = 7); a very low negative partial charge, including aromatic carbons which have a heteroatom-substitution in “ortho” position (PEOE_VSA-0) and molecular descriptor (rsynth: estimating the synthesizability of molecules as the fraction of heavy atoms that can be traced back to starting material fragments resulting from retrosynthetic rules), respectively. The model suggests that the anti-malarial activity of haemozoin inhibitors increases with molecules that have higher average total charge sum in pKa prediction (pH = 7). QSAR model also highlights that the descriptor using atomic contribution to logP or the distance matrix descriptor (GCUT_SLOGP_2), and structural component of the molecules, including topological descriptors does make for better anti-malarial activity. Conclusions: The model is capable of predicting the anti-malarial activities of anti-haemozoin compounds. In addition, the selected molecular descriptors in this QSAR model are helpful in designing more efficient compounds against the P. falciparum 3D7A strain., Malaria Journal, 20, art. no. 264; 2021

Messenger RNA (mRNA) medicine has become a new therapeutic approach owing to the progress in mRNA delivery technology, especially with lipid nanoparticles (LNP). However, mRNA encapsulated-LNP (mRNA-LNP) cannot spontaneously cross the blood-brain barrier (BBB) which prevents the expression of foreign proteins in the brain. Microbubble-assisted focused ultrasound (FUS) BBB opening is an emerging technology that can transiently enhance BBB permeability. In this study, FUS/microbubble-assisted BBB opening was investigated for the intravenous delivery of mRNA LNP to the brain. The intensity of FUS irradiation was optimized to 1.5 kW/cm2, at which BBB opening occurred efficiently without hemorrhage or edema. Exogenous protein (luciferase) expression by mRNA-LNP, specifically at the FUS-irradiated side of the brain, occurred only when FUS and microbubbles were applied. This exogenous protein expression was faster but shorter than that of plasmid DNA delivery. Furthermore, foreign protein expression was observed in the microglia, along with CD31-positive endothelial cells, whereas no expression was observed in astrocytes or neurons. These results support the addition of mRNA-LNP to the lineup of nanoparticles delivered by BBB opening., Journal of Controlled Release, 348, pp. 34-41; 2022

Background Morinda morindoides has been used as herbal medicine in Africa for a long time. It possesses potential therapeutic activities such as antiplasmodial, antispermatogenic, anti-bacterial, anti-fungal, anti-diarrheal effects, stomach pain and constipation reliefs. However, there has been no literature summarising its potential effects. This study therefore aims to systematically review the therapeutic activities of this medicinal plant as well as its pharmacological activities. Materials and methods Nine databases were selected to search suitable articles namely MEDLINE (PubMed), ISI, Scopus, Google Scholar, Global Health Library (GHL), Virtual Health Library (VHL), POPLINE, New York Academy of Medicine gray Literature Report (NYAM), and System for Information on gray Literature in Europe (SIGLE). Based on inclusion and exclusion criteria, we included 54 papers for the systemic review. Results Briefly, in vitro studies showed that M. morindoides possessed anti-malarial, anti-bacterial, anti-fungal, anti-amoebic, anti-larval, spasmolytic, anti-oxidant effects and complementary modulation. Moreover, those effects were emphasized in animal studies. The plant also showed positive activities on body metabolism studied on animal models such as hypotensive, hypoglycemic, hypolipidemic actions. M. morindoides showed its safety on animals’ organs as it did not dramatically change in blood parameters or injure cardiac tissues. However, there were many inconsistent results from various studies in terms of its benefits while its extracts showed a wide range of safety on different cells. Conclusion M. morindoides has proven to have potential therapeutic effects in vitro and in vivo models. Therefore, higher quality studies on human are necessary to be conducted, which can provide stronger evidence to confirm M. morindoides’s effects.

Although several in vitro assays that predict the sensitizing potential of chemicals have been developed, none can distinguish between chemical respiratory and skin sensitizers. Recently, we established a new three-dimensional dendritic cell (DC) coculture system consisting of a human airway epithelial cell line, immature DCs derived from human peripheral monocytes, and a human lung fibroblast cell line. In this coculture system, compared to typical skin sensitizers, typical respiratory sensitizers showed enhanced mRNA expression in DCs of the key costimulatory molecule OX40 ligand (OX40L), which is important for T helper 2 (Th2) cell differentiation. Herein, we established a new two-step DC/T cell coculture system by adding peripheral allogeneic naive CD4+ T cells to the DCs stimulated in the DC coculture system. In this DC/T cell coculture system, typical respiratory sensitizers but not skin sensitizers enhanced mRNA expression of the predominant Th2 marker interleukin-4 (IL-4) and its transcription factor GATA-binding protein 3. To improve the versatility, in place of peripheral monocytes, monocyte-derived proliferating cells called CD14-ML were also used in the DC coculture system. Similar to peripheral monocytes, enhanced mRNA expression of OX40L was observed by typical respiratory sensitizers compared to skin sensitizers. When these cell lines were applied to the DC/T cell coculture system with peripheral allogeneic naive CD4+ T cells, typical respiratory sensitizers but not skin sensitizers enhanced the mRNA expression of IL-4. Thus, this DC/T cell coculture system might be useful for discriminating between respiratory and skin sensitizers by differential mRNA upregulation of IL-4 in T cells.

The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a serious threat to global public health. The emergence of SARS-CoV-2 variants is a significant concern regarding the continued effectiveness of vaccines and antiviral therapeutics. Thus, natural products such as foods, drinks, and other compounds should be investigated for their potential to treat COVID-19. Here, we examined the in vitro antiviral activity against SARS-CoV-2 of various polyethylene terephthalate (PET)-bottled green Japanese teas and tea compounds. Six types of PET-bottled green tea were shown to inhibit SARS-CoV-2 at half-maximal inhibitory concentrations (IC

Three phenylpropanoid-conjugated iridoid glucosides, acetylgaertneric acid (1), acetyldehydrogaertneroside (2), and dehydrogaertneric acid (10), together with nine known related iridoid glucosides (3–9, 11, and 12), two coumaroyl alkaloids, one benzenoid, and three flavonoid glucosides were isolated from leaves of Morinda morindoides (Rubiaceae). Structures of these isolated compounds were determined using spectroscopic analysis. Compounds 1–18 and previously isolated compounds (19–29) were evaluated for anti-trypanosomal activity against Trypanosoma cruzi Tulahuen strain (trypomastigote and amastigote) together with cytotoxicity against host cells, new-born mouse heart cells. Among them, molucidin (21) and prismatomerin (22) exhibited good anti-trypanosomal activity (IC50 of 4.67 and 5.70 µM, respectively), together with cytotoxicity (CC50 of 2.76 and 3.22 μM, respectively). Compounds 1–18 did not show anti-malarial activity against a chloroquine/mefloquine-sensitive strain of Plasmodium falciparum.

OBJECTIVE: We assessed the impact of political conflict (Boko Haram) on tuberculosis (TB) case noti?cations in Adamawa State in North-east Nigeria. DESIGN: A retrospective analysis of TB case notifications from TB registers (2010-2016) to describe changes in TB notification, sex and age ratios by the degree of conflict by local government area. SETTING: Adamawa State. PARTICIPANTS: 21?076 TB cases notified. RESULTS: 21?076 cases (62% male) were noti?ed between 2010 and 2016, of which 19 604 (93%) were new TB cases. Areas affected by conflict in 2014 and 2015 had decreased case notification while neighbouring areas reported increased case notifications. The male to female ratio of TB cases changed in areas in conflict with more female cases being notified. The young and elderly (1-14 and >65 years old) had low notifications in all areas,with a small increase in case notifications during the years of conflict. CONCLUSION: TB case notifications decreased in conflict areas and increased in areas without conflict. More males were notified during peace times and more female cases were reported from areas in conflict. Young and elderly populations had decreased case notifications but experienced a slight increase during the conflict years. These changes are likely to reflect population displacement and a dissimilar effect of conflict on the accessibility of services. TB services in conflict areas deserve further study to identify resilient approaches that could reach affected populations., BMJ open, 10(9), art.no.e035263; 2020

The lack of an appropriate model has been a serious concern in dengue research pertinent to immune response and vaccine development. It remains a matter of impediment in dengue virus (DENV) studies when it comes to an in vitro model, which requires adequate quantity of dendritic cells (DC) with uniform characters. Other sources of DC, mostly monocyte derived DC (moDC), have been used despite their limitations such as quantity, proliferation, and donor dependent characters. Recent development of human iPS cells with consistent proliferation for long, stable, functional characteristics and desired HLA background has certainly offered added advantages. Therefore, we hypothesised that iPS derived cells would be a reliable alternative to the traditional DCs to be used with an in vitro DENV system. To develop a DENV infection and T cell activation model, we utilised iPS cells (HLA-A*24) as the source of DC. iPS-ML-DC was prepared and DENV infectivity was assessed apart from the major surface markers expression and cytokine production potential. Our iPS-ML-DC had major DC markers expression, DENV infection efficiency and cytokine production properties similar to that of moDC. Moreover, DENV infected iPS-ML-DC demonstrated the ability to activate HLA-matched T cell (but not mismatched) in vitro as evidenced by significantly higher proportion of IFN-γ+ CD69+ T cells compared to non-infected iPS-ML-DC. This affirmed the antigen-specific T cell activation by iPS-ML-DC as a function of antigen presenting cells. To conclude, maturation potential, DENV infection efficiency and T cell activation ability collectively suggest that iPS-ML-DC serves as an attractive option of DC for use in DENV studies in vitro.

Dengue virus (DENV) replication between mosquito and human hosts is hypothesized to be associated with viral determinants that interact in a differential manner between hosts. However, the understanding of inter-host viral determinants that drive DENV replication and growth between hosts is limited. Through the use of clinical isolates, we identified an amino acid variation of Ala, Met and Val at position 116 of DENV-1 NS4B. While the proportion of virus with the NS4B-116V variant remained constantly high in serial passages in a mosquito cell line, populations of the NS4B-116M and NS4B-116A variants became dominant after serial passages in mammalian cell lines. Using recombinant DENV-1 viruses, the Val to Ala or Met alteration at position NS4B-116 (rDENV-1-NS4B-116A and rDENV-1-NS4B-116M) resulted in enhanced virus growth in human cells in comparison to the clone with Val at NS4B-116 (rDENV-1-NS4B-116V). However, the reverse phenomenon was observed in a mosquito cell line. Additionally, in a human cell line, differential levels of IFN-α/β and IFN-stimulated gene expressions (IFIT3, IFI44L, OAS1) suggested that the enhanced viral growth was dependent on the ability of the NS4B protein to hamper host IFN response during the early phase of infection. Overall, we identified a novel and critical viral determinant at the pTMD3 of NS4B region that displayed differential effects on DENV replication and fitness in human and mosquito cell lines. Taken together, the results suggest the importance of the NS4B protein in virus replication and adaptation between hosts.

There is no definitive predictor of dengue severity, and this has led to a very large number of unnecessary hospitalizations worldwide. Although mast cell mediators are believed to a play role in dengue severity, the lack of precise kinetic data demands further research on early predictors. We enrolled 111 patients with confirmed dengue and 85 with “other febrile illness” (OFI) in a hospital-based prospective study in Vietnam. Dengue patients were classified as level 1, 2, or 3 based on the clinical intervention received. Blood samples were collected from each patient every day (pre- and post-defervescence) and after discharge. Plasma chymase, total IgE, and dengue-specific IgE were measured. Dengue-specific IgE levels showed an increasing trend during the course of illness and remained high even at post-discharge, although no significant difference was observed among severity levels. Total IgE showed no such trend. The specific IgE/total IgE ratio (S/T ratio) remained constantly higher in level 3 patients compared to other levels, with a significant difference at some time points. The S/T ratio of acute phase samples (before defervescence) tended to increase with increasing severity (level 1 < 2 < 3), and was significantly higher in level 3 patients than in level 1 and OFI patients. As an early predictor of severity allowing level 3 patients to be distinguished from other dengue patients, the S/T ratio achieved a sensitivity of 75% and specificity of 68%. We describe the kinetic profiles of IgEs, their ratio, and chymase levels at different severity levels. The S/T ratio was found to be associated with dengue severity, suggesting that it could potentially be used as an early predictor of severity.

The increasing resistance of malaria to drugs raise the need to new antimalarial agents. Antiplasmodial herbs and their active compounds are the most promising source the new antimalarial agents. This study aimed to identify the medicinal plants with very good in vitro antiplasmodial activities, with half-maximal inhibitory concentration (IC50)≤1μg/ml, and to determine trends in the process of screening their antiplasmodial activities. A total of 58 reports published in the English language were retrieved from the bibliographical databases. Screening and data extraction were performed by two independent reviewers. The herbs were categorized as very good, good, moderate and inactive if the IC50 values were 1-5μg/ml and >5μg/ml respectively. We documented 752 medicinal plants belonging to 254 genera. The majority of the plants were reported from Africa followed by Asia. The traditional use for malaria treatment was the most common reason for the selection of the plants for investigation. About 80% of the plants experimented were reported to be inactive. Among plants identified as having very good to good antiplasmodial crude extracts are Harungana madagascariensis, Quassia africana, and Brucea javanica, while Picrolemma spruce, Aspidosperma vargasi, Aspidosperma desmanthum, and Artemisia annua were reported to have individual compound isolates with very good antiplasmodial activities. In conclusion, the number of plant species assessed so far is still small compared with the stock in nature's plant library. A mechanism of systematically approaching and exploring the untouched plant genera needs to be designed.

Zika virus (ZIKV) is a re-emerging mosquito-borne flavivirus of African origin that is transmitted by Aedes mosquitoes. ZIKV was historically limited to Africa and Asia, where mild cases were reported. However, ZIKV has recently been responsible for major global outbreaks associated with a wide range of neurological complications. Since no antiviral therapy exists for ZIKV, drug discovery research for ZIKV is crucial. Intracellular lipids regulated by sterol regulatory element-binding proteins (SREBPs) are important in flavivirus pathogenesis. PF-429242 has been reported to inhibit the activity of site-1 protease (S1P), which regulates the expression of SREBP target genes. Our primary objective in this study is to elucidate the mechanism of the antiviral activity of PF-429242 against the African genotype (ZIKVMR-766) and Asian genotypes (ZIKV H/PF 2013 and ZIKV PRVABC59) using several primate-derived cell lines. The virus titer was determined via a focus-forming assay; we used flow cytometry to quantify intracellular lipids in ZIKV-infected and mock-treated cells. The PF-429242 molecule effectively suppressed ZIKV infection in neuronal cell lines; T98G, U-87MG, SK-N-SH and primary monocytes cell, indicating that PF-429242 molecule can be used therapeutically. A strong reduction in ZIKV replication was observed at 12 μM and 30 μM in in neuronal cell lines and primary monocytes, respectively. Interestingly, the inhibitory effects of the PF-429242 molecule were observed when it was tested on various ZIKV-lineage infections. Lipid quantification reveals that ZIKV increases lipogenesis in infected cells, while the exogenous addition of cholesterol effectively blocks ZIKV replication. Furthermore, the supplementation of oleic acid increases the ZIKV titer. Fenofibrate, an inhibitor of lipid droplet formation, reduces the ZIKV titer. Collectively, our results demonstrate that the development of antiviral drugs against ZIKV could be based on key regulators of lipid metabolism. In addition, this study reveals that the mechanism of the PF-429242-mediated suppression among flavivirus infections is not entirely identical. Our results warrant further evaluation of PF-429242 as a prospective antiviral drug, given the multiple advantageous properties of this compound, such as its limited toxicity, neuroprotective properties, and broad spectrum of capabilities.

BACKGROUND: The National Program for Chagas disease was implemented in Bolivia in 2006, and it greatly decreased the number of infections through vector control. Subsequently, a treatment regimen of benznidazole (BNZ) was started in seropositive school-age children living in certified vector control areas. METHODS AND FINDINGS: We conducted a 12-month follow-up study and seven blood samples were taken during and after the treatment. Serology, conventional diagnostic PCR (cPCR) and quantitative Real-time PCR (qPCR) were performed. Plasma Th1/Th2/Th17 cytokines levels were also determined. Approximately 73 of 103 seropositive children complied with BNZ, with three interruptions due to side effects. To evaluate each individual's treatment efficacy, the cPCR and qPCR values during the final 6 months of the follow-up period were observed. Among 57 children who completed follow-up, 6 individuals (11%) showed both cPCR(+) and qPCR(+) (non reactive), 24 (42%) cPCR(-) but qPCR(+) (ambiguous) and 27 (47%) cPCR(-) and qPCR(-) (reactive). Within 14 Th1/Th2/Th17 cytokines, IL-17A showed significantly higher levels in seropositive children before the treatment compared to age-matched seronegative children and significantly decreased to the normal level one-year after. Moreover, throughout the follow-up study, IL-17A levels were positively co-related to parasite counts detected by qPCR. At the 12 months' time point, IL-17A levels of non-reactive subjects were significantly higher than either those of reactive or ambiguous subjects suggesting that IL-17A might be useful to determine the reactivity to BNZ treatment. CONCLUSIONS: Plasma levels of IL-17A might be a bio-marker for detecting persistent infection of T. cruzi and its chronic inflammation., PLoS neglected tropical diseases, 13(9), e0007715; 2019

BackgroundChagas disease (CD), typically confined to the Latin America (LA) region, is emerging as a global health problem. In Japan, as in the rest of world, the under-diagnose rate of CD is alarmingly high. Various studies have highlighted the importance of informed knowledge in the seeking behavior. Educational integrative activities, with consideration for socio-cultural factors, can help increase the knowledge of the participants. There has been no studies that analyze the difference in knowledge, before and after these educational activities. This study aimed to qualitatively and quantitatively investigate the knowledge, behavior and attitude toward CD among LA migrants in Japan and to evaluate the effectiveness of the community educational activity in increasing knowledge of CD.MethodologyThis cross-sectional study involved two questionnaires to analyze the knowledge of the LA migrant participants before and after the community activity (CA) in four cities in Japan (Oizumi, Suzuka, Hadano, and Nagoya).Principal FindingsA total of 75 participants were enrolled, predominantly Bolivians from hyperendemic areas. The baseline knowledge of CD was low. However, most of them were familiar with the disease although less than 10% of them had been tested for CD before. Living in Japan for more than 10 years and previously being tested for CD were the factors associated with better knowledge. The conducted CA significantly improved the knowledge of the participants. They associated the term “Chagas” mostly with fear and concern. In contrast to other studies, the level of stigmatization was low. The barriers in care seeking behavior were language, migration process and difficulties to access to the healthcare system.ConclusionEducational activities with integrative approach are useful to increase knowledge of CD. The activity brings the possibility to explore not only the level of knowledge, but also to reveal the experience and to understand the needs of the people at risk.Author SummaryThough the incident rate of Chagas disease (CD) has fallen, more than 7 million people are affected worldwide. The CD prevalence is under-estimated because just 1% of these affected people can access to the diagnosis and treatment. This situation is maintaining mainly for the lack of implication of socio-cultural factors in the interventions to decrease the burden of the disease. Educational activities with integral approach are useful to increase the knowledge of the people at risk. People that have being tested for CD before or living in Japan for more than 10 years have better knowledge about the disease, suggesting the importance of knowledge in the seeking behavior. The authors recommend the implementation of educational activities with integral approach as a strategy to improves the knowledge of Chagas disease among Latin America migrants in Japan.

Background and objectives Modulation of the immune reaction is essential in the development of various diseases, including dengue's “Cytokine Tsunami”, an increase in vascular permeability with concomitant severe vascular leakage. We aim to identify the role of T-helper (Th) cells, Th2 and Th7, with their related cytokines in dengue pathogenesis. Material and methods Nine electronic databases and manual search were applied to detect available publications. A meta-analysis using a fixed- or random-effect model was performed to measure standardized mean difference (SMD) with 95% confidence interval (CI). The National Institute of Health (NIH) tools for observational cohort, cross-sectional, and case-control studies were used to examine the risk of bias. The protocol was recorded in PROSPERO with CRD42017060230. Results A total of 38 articles were found including 19 case-control, 11 cross-sectional and 8 prospective cohort studies. We indicated that Th2 cytokines (IL-4, IL-6, IL-8) and Th17 cytokine (IL-17) in dengue patients were notably higher than in a healthy control group in acute phase (SMD = 1.59, 95% CI [0.68, 2.51], p = 0.001; SMD = 1.24, 95% CI [0.41, 2.06], p = 0.003; SMD = 1.13, 95% CI [0.61, 1.66], p Conclusions This study provides evidence of the significant roles of IL-4, IL-6, IL-8, IL-10 and IL-17 in the pathogenesis of developing a severe reaction in dengue fever. However, to fully determine the association of Th cytokines with dengue, it is necessary to perform further studies to assess kinetic levels during the duration of the illness.

BACKGROUND: Herbal medicine has been a rich source of new drugs exemplified by quinine and artemisinin. In this study, a variety of Japanese traditional herbal medicine ('Kampo') were examined for their potential anti-malarial activities. METHODS: A comprehensive screening methods were designed to identify novel anti-malarial drugs from a library of Kampo herbal extracts (n?=?120) and related compounds (n?=?96). The anti-malarial activity was initially evaluated in vitro against chloroquine/mefloquine-sensitive (3D7) and-resistant (Dd2) strains of Plasmodium falciparum. The cytotoxicity was also evaluated using primary adult mouse brain cells. After being selected through the first in vitro assay, positive extracts and compounds were examined for possible in vivo anti-malarial activity. RESULTS: Out of 120 herbal extracts, Coptis rhizome showed the highest anti-malarial activity (IC50 1.9 μg/mL of 3D7 and 4.85 μg/mL of Dd2) with a high selectivity index (SI)?>?263 (3D7) and?>?103 (Dd2). Three major chlorinated compounds (coptisine, berberine, and palmatine) related to Coptis rhizome also showed anti-malarial activities with IC50 1.1, 2.6, and 6.0 μM (against 3D7) and 3.1, 6.3, and 11.8 μM (against Dd2), respectively. Among them, coptisine chloride exhibited the highest anti-malarial activity (IC50 1.1 μM against 3D7 and 3.1 μM against Dd2) with SI of 37.8 and 13.2, respectively. Finally, the herbal extract of Coptis rhizome and its major active compound coptisine chloride exhibited significant anti-malarial activity in mice infected with Plasmodium yoelii 17X strain with respect to its activity on parasite suppression consistently from day 3 to day 7 post-challenge. The effect ranged from 50.38 to 72.13% (P?0.05) for Coptis rhizome and from 81 to 89% (P?

Background: Considerable progress has been made in dengue management, however the lack of appropriate predictors of severity has led to huge number of unwanted admissions mostly decided on the grounds of warning signs. Apoptosis related mediators,among others, are known to correlate with severe dengue (SD) although no predictive validity is established. The objective of this study was to investigate the association of plasma cell-free DNA (cfDNA) with SD, and evaluate its prognostic value in SD prediction at acute phase. Methods: This was a hospital-based prospective cohort study conducted in Vietnam.All the recruited patients were required to be admitted to the hospital and were strictly monitored for various laboratory and clinical parameters(including progression to SD) until discharged. Plasma samples collected during acute phase (6-48 h before defervescence) were used to estimate the level of cfDNA. Results: Of the 61 dengue patients,SD patients (n = 8)developed shock syndrome in 4.8 days (95% CI 3.7-5.4) after the fever onset. Plasma cfDNA levels before the defervescence of SD patients were significantly higher than the non-SD group (p = 0.0493). From the receiver operating characteristic (ROC) curve analysis, a cut-off of > 36.9 ng/mL was able to predict SD with a good sensitivity (87.5%), specificity (54.7%), and area under the curve (AUC) (0.72, 95% CI 0.55-0.88; p = 0.0493).Conclusions: Taken together, these findings suggest that cfDNA could serve as a potential prognostic biomarker of SD. Studies with cfDNA kinetics and its combination with other biomarkers and clinical parameters would further improve the diagnostic ability for SD., Annals of Clinical Microbiology and Antimicrobials, 18(1), art.no.10; 2019

Oxidosqualene cyclase (OSC), a membrane-associated protein, is a key enzyme of sterol biosynthesis. Here we report a novel assay for OSC, involving reaction in aqueous solution, NMR quantification in organic solvent, and factor analysis of spectra. We evaluated one known and three novel inhibitors on OSC of Trypanosoma cruzi, a parasite causative of Chagas disease, and compared their effects on human OSC for selectivity. Among them, one novel inhibitor showed a significant parasiticidal activity.

Ginsenoside Rh1 is one of major bioactive compounds extracted from red ginseng, which has been increasingly used for enhancing cognition and physical health worldwide. The objective of this study was to review the pharmacological effects of ginsenoside Rh1 in a systematic manner. We performed searches on eight electronic databases including MEDLINE (Pubmed), Scopus, Google Scholar, POPLINE, Global Health Library, Virtual Health Library, the System for Information on Grey Literature in Europe, and the New York Academy of Medicine Grey Literature Report to select the original research publications reporting the biological and pharmacological effects of ginsenoside Rh1 from in vitro and in vivo studies regardless of publication language and study design. Upon applying the inclusion and exclusion criteria, we included a total of 57 studies for our systemic review. Ginsenoside Rh1 exhibited the potent characteristics of anti-inflammatory, antioxidant, immunomodulatory effects, and positive effects on the nervous system. The cytotoxic effects of ginsenoside Rh1 were dependent on different types of cell lines. Other pharmacological effects including estrogenic, enzymatic, anti-microorganism activities, and cardiovascular effects have been mentioned, but the results were considerably diverged. A higher quality of evidence on clinical trial studies is highly recommended to confirm the consistent efficacy of ginsenoside Rh1.

The objective was to assess the immunoequivalence and protective efficacy of the novel, relatively safe dendrigraft poly-l-lysine-based nanoparticle formulation in comparison to the non-degradable polyethylenimine-based system. Groups of 6-week-old female C57BL/6 mice were immunized three times biweekly. Each mouse received 100 µg of the Plasmodium yoelii GPI8p-transamidase PyTAM formulated with nanoball that consisted of PyTAM/PEI/γ-PGA or PyTAM/DGL/γ-PGA and their respective nanoparticle-coated blank vector controls. Two weeks after the last immunization, the humoral responses and cellular immune response were assessed. The survival and parasitemia were evaluated in each group challenged intraperitoneally with 106 of a lethal strain of P. yoelii 17XL-parasitized red blood cells. Mice immunized with PyTAM/PEI/γ-PGA or PyTAM/DGL/γ-PGA showed similar survival rates, humoral responses and T helper 1 pro-inflammatory cellular immune responses in vivo and ex vivo. In particular, the PyTAM/DGL/γ-PGA formulation showed a significant increase in conventional dendritic cells in the spleen, which were consistently associated with high interleukin-12 production, the driver of the T helper 1 response. We show that the substitution of non-degradable polyethylenimine with the biodegradable dendrigraft poly-l-lysine in the nanoparticle formulation is immunoequivalent and elicits protective immunity against the lethal strain of P. yoelii. Therefore, this new gene-delivery vehicle with a good safety profile presents an exciting prospect for application in vaccination strategies.

Metformin, a prescribed drug for type 2 diabetes, has been reported to have anti-cancer effects; however, the underlying mechanism is poorly understood. Here we show that this mechanism may be immune-mediated. Metformin enabled normal but not T-cell-deficient SCID mice to reject solid tumors. In addition, it increased the number of CD8(+) tumor-infiltrating lymphocytes (TILs) and protected them from apoptosis and exhaustion characterized by decreased production of IL-2, TNFα, and IFNγ. CD8(+) TILs capable of producing multiple cytokines were mainly PD-1(-)Tim-3(+), an effector memory subset responsible for tumor rejection. Combined use of metformin and cancer vaccine improved CD8(+) TIL multifunctionality. The adoptive transfer of antigen-specific CD8(+) T cells treated with metformin concentrations as low as 10 μM showed efficient migration into tumors while maintaining multifunctionality in a manner sensitive to the AMP-activated protein kinase (AMPK) inhibitor compound C. Therefore, a direct effect of metformin on CD8(+) T cells is critical for protection against the inevitable functional exhaustion in the tumor microenvironment.

The rapid spread of strains of malaria parasites that are resistant to several drugs has threatened global malaria control. Hence, the aim of this study was to predict the antimalarial activity of chemical compounds that possess anti-hemozoin-formation activity as a new means of antimalarial drug discovery. After the initial in vitro anti-hemozoin-formation high-throughput screening (HTS) of 9,600 compounds, a total of 224 hit compounds were identified as hemozoin inhibitors. These 224 compounds were tested for in vitro erythrocytic antimalarial activity at 10 μM by using chloroquine-mefloquine-sensitive Plasmodium falciparum strain 3D7A. Two independent experiments were conducted. The physicochemical properties of the active compounds were extracted from the ChemSpider and SciFinder databases. We analyzed the extracted data by using Bayesian model averaging (BMA). Our findings revealed that lower numbers of S atoms; lower distribution coefficient (log D) values at pH 3, 4, and 5; and higher predicted distribution coefficient (ACD log D) values at pH 7.4 had significant associations with antimalarial activity among compounds that possess anti-hemozoin-formation activity. The BMA model revealed an accuracy of 91.23%. We report new prediction models containing physicochemical properties that shed light on effective chemical groups for synthetic antimalarial compounds and help with in silico screening for novel antimalarial drugs.

Priming of CD8(+) T cells requires two signals, one produced by T‐cell receptor recognition of antigen, and a second that is often provided by the innate immune response. In this context, antigens non‐covalently or covalently associated with heat shock proteins (HSP) are internalized and processed in antigen‐presenting cells (APC) to be presented by MHC I molecules to CD8(+) T cells, thus, signal 1 has been well characterized in this pathway of cross‐presentation. Signal 2 is not fully understood, although there are reports that Toll‐like receptors (TLRs) interact with HSP and activate APC. The ability of HSP to activate APC through TLRs is, however, controversial because of the possibility of endotoxin contamination. Using a variety of TLR KO mice, we present evidence that TLRs (TLR2, 3, 4, 7, and 9) and their adaptor molecules MyD88 and IRAK4 are dispensable in cross‐priming by a mycobacterial HSP70–antigen (ovalbumin as a model antigen) fusion protein; in contrast, MyD88/IRAK4, but not TLRs, are required for tumor rejection induced by the same reagent. Our results indicate that HSP‐mediated cross‐priming uses a second signal produced by mechanisms other than TLR cascades. We hypothesize that efficient cross‐priming by HSP70 alone is insufficient for tumor rejection and that MyD88/IRAK4‐dependent inflammatory stimulation, which might contribute to maintenance of the initially primed effector cells, is required to eradicate tumor burden. (Cancer Sci 2012; 103: 851–859)

In antigen (Ag) cross-presentation, dendritic cells (DCs) take up extracellular Ag and translocate them from the endosome to the cytosol for proteasomal degradation. The processed peptides can enter the conventional MHC I pathway. The molecules responsible for the translocation of Ag across the endosomal membrane into the cytosol are unknown. Here we demonstrate that heat shock protein 90 (HSP90) is critical for this step. Cross-presentation and -priming were decreased in both HSP90α-null DCs and mice. CD8α + DC apoptosis mediated by translocation of exogenous cytochrome c to the cytosol was also eliminated in HSP90α-null mice. Ag translocation into the cytosol was diminished in HSP90α-null DCs and in DCs treated with an HSP90 inhibitor. Internalized Ag was associated with HSP90 and translocated to the cytosol, a process abrogated by the HSP90 inhibitor. Ag within purified phagosomes was released in an HSP90-dependent manner. These results demonstrate the important role of HSP90 in cross-presentation by pulling endosomal Ag out into the cytosol.

Extracellular HSP90 associated with Ag peptides have been demonstrated to efficiently cross-prime T cells, following internalization by dendritic cells (DCs). In addition, the nature of cell-associated Ags required for cross-priming is implicated as peptides and proteins chaperoned by heat shock protein (HSP). However, the role of endogenous HSP in DCs during cross-presentation remains elusive. In this paper, we show that endogenous HSP90 is essential for cross-presentation of both soluble and cell-associated Ags in DCs. Cross-presentation of soluble OVA and OVA-loaded transporter associated with Ag processing-1–deficient cells by bone marrow-derived DCs and DC-like cell line DC2.4 was profoundly blocked by HSP90 inhibitors, whereas presentation of endogenously expressed OVA was only partially suppressed. Assays using small interfering RNA and heat shock factor-1–deficient DCs (with defective expression of HSP90α) revealed the pivotal role of HSP90α in cross-presentation. The results suggest that in addition to HSP90 in Ag donor cells, endogenous HSP90 in DCs plays an essential role during Ag cross-presentation and, moreover, points to a link between heat shock factor-1–dependent induction of HSP90α within DC and cytotoxic T cell immunity.

Heat shock protein 90 (hsp90) and the proteasome activator PA28 stimulate major histocompatibility complex (MHC) class I antigen processing. It is unknown whether hsp90 influences the proteasome activity to produce T cell epitopes, although association of PA28 with the 20 S proteasome stimulates the enzyme activity. Here, we show that hsp90 is essential in assembly of the 26 S proteasome and as a result, is involved in epitope production. Addition of recombinant hsp90alpha to cell lysate enhanced chymotrypsin-like activity of the 26 S proteasome in an ATP-dependent manner as determined by an in-gel hydrolysis assay. We successfully pulled down histidine-tagged hsp90alpha- and PA28alpha-induced, newly assembled 26 S proteasomes from the cell extracts for in vitro epitope production assay, and we found these structures to be sensitive to geldanamycin, an hsp90 inhibitor. We found a cleaved epitope unique to the proteasome pulled down by both hsp90alpha and PA28alpha, whereas two different epitopes were identified in the hsp90alpha- and PA28alpha-pulldowns, respectively. Processing of these respective peptides in vivo was enhanced faithfully by the protein combinations used for the proteasome pulldowns. Inhibition of hsp90 in vivo by geldanamycin partly disrupted the 26 S proteasome structure, consistent with down-regulated MHC class I expression. Our results indicate that hsp90 facilitates MHC class I antigen processing through epitope production in a complex of the 26 S proteasome.

There is still urgent need for a vaccine against schistosomiasis, especially in Schistosoma japonicum endemic areas where even a vaccine that will interrupt zoonotic transmission will be potentially effective as an intervention tool. We had developed a novel nanoparticle gene delivery system, which has proven efficacious in gene transfection to target immune cells with complementary adjuvant effect and high protective efficacy in several diseases. Here, we applied this nanoparticle system in combination with S. japonicum glutathione S-transferase (SjGST) DNA vaccine to show the immunogenicity and anti-fecundity effect of the nanoparticle coated vaccine formulation against murine schistosomiasis. The nanoparticle-coated DNA vaccine formulation induced desired immune responses. In comparison with the nanoparticle coated empty vector, it produced significantly increased antigen-specific humoral response, T-helper 1 polarized cytokine environment, higher proportion of IFN-γ producing CD4(+) T-cells and the concomitant decrease in IL-4 producing CD4(+) T-cells. Although there was no effect on worm burden, we recorded a marked reduction in tissue egg burden. There was up to 71.3% decrease in tissue egg burden and 55% reduction in the fecundity of female adult worms. Our data showed that SjGST DNA vaccine, delivered using the nanoparticle gene delivery system, produced anti-fecundity effect on female adult schistosomes as previously described by using conventional subunit vaccine with adjuvant, proving this DNA vaccine formulation as a promising candidate for anti-pathology and transmission blocking application.

CD8 T cells play a critical role in the host defense against cancers and infectious diseases. However, the presence of antigen-specific CD8 T cells does not always imply that cancers and/or pathogens are efficiently eliminated in the body. Concerning this point, the recent studies suggest the concept of immune exhaustion of CD8 T cells, characterized by their decreased production of IL-2, TNFα, and IFNγ even after antigen stimulation. Thus, continuous stimulation of CD8 T cells by the persistent antigens results in immune exhaustion, which eventually causes immune tolerance against cancers and chronic infections. The identification of immune effector and/or exhausted CD8 T cells by monitoring multiple parameters including T cell exhaustion markers such as PD-1 and Tim-3 and intracellular cytokines is, therefore, crucial to understand the real-time, ongoing immune status. For this purpose, polychromatic flow cytometry is the most common and reliable tool to monitor T cell functions. We describe here the method for detection of immune-exhaustion status of CD8 T cells from human peripheral blood mononuclear cells (PBMCs). By stimulation of PBMCs with PMA/ionomycin for 6 h, more than 1-2 % of total CD8 T cells are identified as positive in terms of multifunctionality, thus producing multiple cytokines--IL-2, TNFα, and IFNγ--at single-cell level in case of all healthy donors. By contrast, CD8 T cells from certain populations of cancer patients are significantly less effective; less than 0.5 % of CD8 T cells are positive in producing such multiple cytokines. The cutoff value around 0.5 % of CD8 T cells might distinguish patients who would receive beneficial effect by cancer vaccine from those who would not respond to the vaccine. Thus, the remaining capacity to produce multiple cytokines of CD8 T cells might be a critical parameter determining the outcome of cancer patients who receive various kinds of cancer vaccines. The method to monitor the state of multifunctionality of CD8 T cells, as described here, would become more important to understand the immune statues in cancers and chronic infectious diseases such as AIDS and malaria infections.

CD8 T cells play a critical role in the host defense against cancers and infectious diseases. However, the presence of antigen-specific CD8 T cells does not always imply that cancers and/or pathogens are efficiently eliminated in the body. Concerning this point, the recent studies suggest the concept of immune exhaustion of CD8 T cells, characterized by their decreased production of IL-2, TNFα, and IFNγ even after antigen stimulation. Thus, continuous stimulation of CD8 T cells by the persistent antigens results in immune exhaustion, which eventually causes immune tolerance against cancers and chronic infections. The identification of immune effector and/or exhausted CD8 T cells by monitoring multiple parameters including T cell exhaustion markers such as PD-1 and Tim-3 and intracellular cytokines is, therefore, crucial to understand the real-time, ongoing immune status. For this purpose, polychromatic flow cytometry is the most common and reliable tool to monitor T cell functions. We describe here the method for detection of immune-exhaustion status of CD8 T cells from human peripheral blood mononuclear cells (PBMCs). By stimulation of PBMCs with PMA/ionomycin for 6 h, more than 1-2 % of total CD8 T cells are identified as positive in terms of multifunctionality, thus producing multiple cytokines--IL-2, TNFα, and IFNγ--at single-cell level in case of all healthy donors. By contrast, CD8 T cells from certain populations of cancer patients are significantly less effective; less than 0.5 % of CD8 T cells are positive in producing such multiple cytokines. The cutoff value around 0.5 % of CD8 T cells might distinguish patients who would receive beneficial effect by cancer vaccine from those who would not respond to the vaccine. Thus, the remaining capacity to produce multiple cytokines of CD8 T cells might be a critical parameter determining the outcome of cancer patients who receive various kinds of cancer vaccines. The method to monitor the state of multifunctionality of CD8 T cells, as described here, would become more important to understand the immune statues in cancers and chronic infectious diseases such as AIDS and malaria infections.