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Leprosy is a chronic disease of the skin and peripheral nerves caused by Mycobacterium leprae. A major public health and clinical problem are leprosy reactions, which are inflammatory episodes that often contribute to nerve damage and disability. Type I reversal reactions (T1R) can occur after microbiological cure of leprosy and affect up to 50% of leprosy patients. Early intervention to prevent T1R and, hence, nerve damage, is a major focus of current leprosy control efforts. In a prospective study, we enrolled and collected samples from 32 leprosy patients before the onset of T1R. Whole blood aliquots were challenged with M. leprae sonicate or media and total RNA was extracted. After a three-year follow-up, the transcriptomic response was compared between cells from 22 patients who remained T1R-free and 10 patients who developed T1R during that period. Our analysis focused on differential transcript (i.e. isoform) expression and usage. Results showed that, at baseline, cells from T1R-destined and T1R-free subjects had no main difference in their transcripts expression and usage. However, the cells of T1R patients displayed a transcriptomic immune response to M. leprae antigens that was significantly different from the one of cells from leprosy patients who remained T1R-free. Transcripts with significantly higher upregulation in the T1R-destined group, compared to the cells from T1R-free patients, were enriched for pathways and GO terms involved in response to intracellular pathogens, apoptosis regulation and inflammatory processes. Similarly, transcript usage analysis pinpointed different transcript proportions in response to the in-vitro challenge of cells from T1R-destined patients. Hence, transcript usage in concert with transcript expression suggested a dysregulated inflammatory response including increased apoptosis regulation in the peripheral blood cells of T1R-destined patients before the onset of T1R symptoms. Combined, these results provided detailed insight into the pathogenesis of T1R., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Correa-Macedo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

This report documents the first known cases of lepromatous leprosy in patients with chronic mucocutaneous candidiasis (CMC) linked to a gain-of-function mutation in the STAT1 gene. Two related patients, a mother and daughter, who both suffer from CMC and lepromatous leprosy, carry a heterozygous STAT1 mutation (c.821G>A; p.R274Q). Both individuals exhibited similarly high levels of total and phosphorylated STAT1 in CD4+ T cells and decreased interleukin 17A transcripts. This mutation underscores a complex relationship between genetic susceptibility to infections and the necessity to evaluate each case individually.

Background Leprosy is no longer considered an imprecation, as an effective multidrug therapy regimen is available worldwide for its cure. However, its diverse clinical manifestations sometimes involve acute inflammatory reactions. These complications result in irreversible nerve damage, neuritis and anatomical deformities that emerge before, during the treatment or after the completion of treatment. Reversal reaction (Type-I) and erythema nodosum leprosum (Type-II) are the leprosy reactions generally seen in patients with lepromatous and borderline forms of leprosy. At present, there is no accurate diagnostic test available to detect these leprosy reactions. Objectives To identify potential biomarkers indicative of Type-I and Type-II leprosy reactions that could help in their early diagnosis. Methods and Results Host-transcriptomics investigations have been utilised in this study to decipher a correlation between host-gene expression-based biomarkers and exacerbation of leprosy reactions. We present a comparative analysis of publicly available host transcriptomics datasets (from Gene Expression Omnibus) related to leprosy reactions. Individual datasets were analysed and integration of results was carried out using meta-analysis. Common differentially expressed genes (DEGs) were identified using the frequentist and Bayesian ratio association test methods. We have identified several genes - ADAMTS5, ADAMTS9, IFITM2, IFITM3, KIRREL, ANK3, CD1E, CTSF, DOCK9 and KRT73 to name a few - which can serve as potential biomarkers for Type-II reaction. Similarly, ACP5, APOC1, CCL17, S100B, SLC11A1 among others may likely serve as biomarkers for Type-I reaction. Limitations The number of datasets related to leprosy reactions found after the systematic search is less (n = 4) and may limit the accuracy of identified biomarker genes. This could be resolved by including more studies in the data analysis. Conclusion We provide a comprehensive list of gene candidates which could be prioritised further in research focusing on immune reactions in leprosy, as they are likely important in understanding its complexities and could be useful in its early diagnosis.

Background: Which cell populations that determine the fate of bacteria in infectious granulomas remain unclear. Leprosy, a granulomatous disease with a strong genetic predisposition, caused by Mycobacterium leprae infection, exhibits distinct sub-types with varying bacterial load and is considered an outstanding disease model for studying host-pathogen interactions., Methods: We performed single-cell RNA and immune repertoire sequencing on 11 healthy controls and 20 patients with leprosy, and integrated single-cell data with genome-wide genetic data on leprosy. Multiplex immunohistochemistry, and in vitro and in vivo infection experiments were conducted to confirm the multimodal omics findings., Findings: Lepromatous leprosy (L-LEP) granulomas with high bacterial burden were characterised by exhausted CD8 + T cells, and high RGS1 expression in CD8 + T cells was associated with L-LEP. By contrast, tuberculoid leprosy (T-LEP) granulomas with low bacterial burden displayed enrichment in resident memory IFNG + CD8 + T cells (CD8 + Trm) with high GNLY expression. This enrichment was potentially attributable to the communication between IL1B macrophages and CD8 + Trm via CXCL10-CXCR3 signalling. Additionally, IL1B macrophages in L-LEP exhibited anti-inflammatory phenotype, with high APOE expression contributing to high bacterial burden. Conversely, IL1B macrophages in T-LEP were distinguished by interferon-γ induced GBP family genes., Interpretation: The state of IL1B macrophages and functional CD8 + T cells, as well as the relationship between them, is crucial for controlling bacterial persistence within granulomas. These insights may indicate potential targets for host-directed immunotherapy in granulomatous diseases caused by mycobacteria and other intracellular bacteria., Funding: The Key research and development program of Shandong Province (2021LCZX07), Natural Science Foundation of Shandong Province (ZR2023MH046), Youth Science Foundation Cultivation Funding Plan of Shandong First Medical University (Shandong Academy of Medical Sciences) (202201-123), National Natural Science Foundation of China (82471800, 82230107, 82273545, 82304039), the China Postdoctoral Science Foundation (2023M742162), Shandong Province Taishan Scholar Project (tspd20230608), Joint Innovation Team for Clinical & Basic Research (202410), Central guidance for local scientific and technological development projects of Shandong Province (YDZX2023058)., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: The importance of DNA repair enzymes in maintaining genomic integrity is highlighted by the hypothesis that DNA damage by reactive oxygen/nitrogen species produced inside the host cell is essential for the mutagenesis process. Endonuclease III (Nth), formamidopyrimide (Fpg) and endonuclease VIII (Nei) DNA glycosylases are essential components of the bacterial base excision repair process. Mycobacterium leprae lost both fpg/nei genes during the reductive evolution event and only has the nth (ML2301) gene. This study aims to characterize the mutations in the nth gene of M. leprae strains and explore its correlation with drug-resistance., Method: A total of 91 M. leprae positive DNA samples extracted from skin biopsy samples of newly diagnosed leprosy patients from NSCB Hospital Jabalpur were assessed for the nth gene as well as drug resistance-associated loci of the rpoB, gyrA and folP1 genes through PCR followed by Sanger sequencing., Results: Of these 91 patients, a total of two insertion frameshift mutations, two synonymous and seven nonsynonymous mutations were found in nth in seven samples. Sixteen samples were found to be resistant to ofloxacin and one was found to be dapsone resistant as per the known DRDR mutations. No mutations were found in the rpoB region. Interestingly, none of the nth mutations were identified in the drug-resistant associated samples., Conclusion: The in-silico structural analysis of the non-synonymous mutations in the Nth predicted five of them were to be deleterious. Our results suggest that the mutations in the nth gene may be potential markers for phylogenetic and epidemiological studies., Competing Interests: Declaration of competing interest None., (Copyright © 2023 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Leprosy has a high rate of cripplehood and lacks available early effective diagnosis methods for prevention and treatment, thus novel effective molecule markers are urgently required. In this study, we conducted bioinformatics analysis with leprosy and normal samples acquired from the GEO database(GSE84893, GSE74481, GSE17763, GSE16844 and GSE443). Through WGCNA analysis, 85 hub genes were screened(GS > 0.7 and MM > 0.8). Through DEG analysis, 82 up-regulated and 3 down-regulated genes were screened(|Log2FC| > 3 and FDR < 0.05). Then 49 intersection genes were considered as crucial and subjected to GO annotation, KEGG pathway and PPI analysis to determine the biological significance in the pathogenesis of leprosy. Finally, we identified a gene-pathway network, suggesting ITK, CD48, IL2RG, CCR5, FGR, JAK3, STAT1, LCK, PTPRC, CXCR4 can be used as biomarkers and these genes are active in 6 immune system pathways, including Chemokine signaling pathway, Th1 and Th2 cell differentiation, Th17 cell differentiation, T cell receptor signaling pathway, Natural killer cell mediated cytotoxicity and Leukocyte transendothelial migration. We identified 10 crucial gene markers and related important pathways that acted as essential components in the etiology of leprosy. Our study provides potential targets for diagnostic biomarkers and therapy of leprosy., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Zhou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Mycobacterium leprae infects skin and peripheral nerves causing a broad of clinical forms. MicroRNAs (miRNAs) control immune mechanisms such as apoptosis, autophagy as well as to target genes leading to abnormal proliferation, metastasis, and invasion of cells. Herein we evaluated miRNAs expression for leprosy phenotypes in biopsies obtained from patients with and without reactions. We also correlated those miRNAs with both, bacillary index (BI) and genes involved in the micobacteria elimination process. Our results show a significant increase in the miR-125a-3p expression in paucibacillary (PB) patients vs multibacillary (MB) subjects (p = 0.007) and vs reversal reactions (RR) (p = 0.005), respectively. Likewise, there was a higher expression of miR-125a-3p in patients with erythema nodosum leprosum (ENL) vs MB without reactions (p = 0.002). Furthermore, there was a positive correlation between miR-125a-3p, miR-146b-5p and miR-132-5p expression and BI in patients with RR and ENL. These miRNAS were also correlated with genes such as ATG12 (miR-125a-3p), TNFRSF10A (miR-146b-5p), PARK2, CFLAR and STX7 (miR-132-5p). All together we underpin a role for these miRNAs in leprosy pathogenesis, implicating mechanisms such as apoptosis and autophagy in skin. The miR-125a-3p might have a distinct role associated with PB phenotype and ENL in MB patients., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Background: C-C motif chemokine ligand 2, a gene that codes for a protein involved in inflammation. Certain SNPs in the CCL2 gene have been studied for their potential associations with susceptibility to various diseases. These SNPs may affect the production and function of the CCL2 protein, which is involved in the recruitment of immune cells to the site of inflammation. Variations in CCL2 may influence the immune response to Mycobacterium leprae infection., Objective: To investigate the association of the C-C motif chemokine ligand-2 single nucleotide polymorphisms with leprosy., Methods: CCL2 single nucleotide polymorphisms were analyzed in a total of 975 leprosy patients and 357 healthy controls. Of those, 577 leprosy and 288 healthy controls were analyzed by PCR-RFLP for CCL2 -2518 A>G, 535 leprosy and 290 controls for CCL2 -362 G>C, 295 leprosy and 240 controls for CCL2 -2134 T>G, 325 leprosy and 288 controls for CCL2 -1549 A>T SNPs by melting curve analysis using hybridization probe chemistry and detection by fluorescence resonance energy transfer (FRET) technique in Realtime PCR. The levels of CCL2, IL-12p70, IFN-γ, TNF-α, and TGF-β were estimated in sera samples and correlated with CCL2 genotypes., Results: The frequency of the GCT (-2518 A>G, -362 G>C, -2134 T>G) haplotype is observed to be higher in leprosy patients compared to healthy controls (P = 0.04). There was no significant difference observed in genotypic frequencies between leprosy patients and healthy controls {(-2518A>G, p = 0.53), (-362 G>C, p = 0.01), (-2134 T>G, p = 0.10)}. G allele at the -2134 site is predominant in leprosy (borderline) without any reaction (8 %) compared to borderline patients with RR reactions (2.1 %) (P = 0.03). GG genotype (p = 0.008) and G allele at -2518 (p = 0.030) of the CCL 2 gene were found to be associated with patients with ENL reaction. An elevated level of serum CCL2 was observed in leprosy patients with the -2518 AA and AG genotypes (p = 0.0001)., Conclusions: G allele and GG genotype at the CCL2 -2518 site are associated with a risk of ENL reactions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Objectives: Mycobacterium leprae is able to infect Schwann cells leading to neural damage. Neurotrophins are involved in nervous system plasticity and impact neural integrity during diseases. Investigate the association between single nucleotide polymorphisms in neurotrophin genes and leprosy phenotypes, especially neural damage., Design: We selected single nucleotide polymorphisms in neurotrophins or their receptors genes associated with neural disorders: rs6265 and rs11030099 of brain-derived neurotrophic factor (BDNF), rs6330 of BDNF, rs6332 in NT3 and rs2072446 of P75NTR. The association of genetic frequencies with leprosy phenotypes was investigated in a case-control study., Results: An association of the BDNF single nucleotide polymorphism rs11030099 with the number of affected nerves was demonstrated. The "AA+AC" genotypes were demonstrated to be protective against nerve impairment. However, this variation does not affect BDNF serum levels. BDNF is an important factor for myelination of Schwann cells and polymorphisms in this gene can be associated with leprosy outcome. Moreover, rs11030099 is located in the binding region for micro-RNA (miRNA) 26a that could be involved in control of BDNF expression. We demonstrated different expression levels of this miRNA in polar forms of leprosy., Conclusion: Our findings demonstrate for the first time an association between the polymorphism rs11030099 in the BDNF gene and neural commitment in leprosy and may indicate a possible role of miRNA-26a acting synergistically to these genetic variants in neural damage development., Competing Interests: Declarations of competing interest The authors have no competing interests to declare., (Copyright © 2024. Published by Elsevier Ltd.)

Mycobacterium leprae-infected macrophages preferentially exhibit the regulatory M2 phenotype in vitro, which helps the immune escape unabated growth of M leprae in host cells. The mechanism that triggers macrophage polarization is still unknown. In this study, we performed single-cell RNA sequencing to determine the initial responses of human monocyte-derived macrophages against M leprae infection of 4 healthy individuals and found an increase in a major alternative-activated macrophage type that overexpressed NEAT1, CCL2, and CD163. Importantly, further functional analysis showed that ferroptosis was positively correlated with M2 polarization of macrophages, and in vitro experiments have shown that inhibition of ferroptosis promotes the survival of M leprae within macrophages. In addition, further joint analysis of our results with mutisequencing data from patients with leprosy and in vitro validation identified that CYBB was the pivotal molecule for ferroptosis that could promote the M2 polarization of M leprae-infected macrophages, resulting in the immune escape and unabated growth of pathogenic bacteria. Overall, our results suggest that M leprae facilitated its survival by inducing CYBB-mediated macrophage ferroptosis leading to its alternative activation and might reveal the potential for a new therapeutic strategy of leprosy., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The current meta-analysis aims to explore the potential correlation between natural resistance-associated macrophage protein 1 (NRAMP1) (3'-Untranslated region [3'-UTR]) and nucleotide-binding oligomerization domain-2 (NOD2 [rs8057341]) gene polymorphisms and their association with leprosy susceptibility in both Asian and Caucasian populations. Datas were retrieved from case control studies with NOD 2 and NRAMP 1 gene polymorphism associated with leprosy disease. Leprosy emerges as a particularly distinctive ailment among women on a global scale. The NRAMP1 (3'-UTR) and NOD2 (rs8057341) genetic variations play a crucial role in the progression of leprosy. A systematic review of relevant case-control studies was conducted across several databases, including ScienceDirect, PubMed, Google Scholar, and Embase. Utilizing MetaGenyo and Review Manager 5.4 Version, statistical analyses were carried out. Nine case-control studies totaling 3281 controls and 3062 leprosy patients are included in the research, with the objective of examining the potential association between NRAMP1 (3'-UTR) and NOD2 (rs8057341) gene polymorphisms and leprosy risk. The review methodology was registered in PROSPERO (ID520883). The findings reveal a robust association between NRAMP1 (3'-UTR) and NOD2 (rs8057341) gene polymorphisms and leprosy risk across various genetic models. Although the funnel plot analysis did not identify publication bias, bolstering these findings and elucidating potential gene-gene and gene-environment interactions require further comprehensive epidemiological research. This study identified a strong correlation between polymorphisms in the NOD2 (rs8057341) genes and susceptibility to leprosy across two genetic models. Further comprehensive epidemiological investigations are warranted to validate these findings and explore potential interactions between these genes and environmental factors., (Copyright © 2024 Copyright: © 2024 International Journal of Mycobacteriology.)

Leprosy is a chronic bacterial infection mainly caused by Mycobacterium leprae that primarily affects skin and peripheral nerves. Due to its ability to absorb carbon from the host cell, the bacillus became dependent on energy production, mainly through oxidative phosphorylation. In fact, variations in genes of Complex I of oxidative phosphorylation encoded by mtDNA have been associated with several diseases in humans, including bacterial infections, which are possible influencers in the host response to leprosy. Here, we investigated the presence of variants in the mtDNA genes encoding Complex I regarding leprosy, as well as the analysis of their pathogenicity in the studied cohort. We found an association of 74 mitochondrial variants with either of the polar forms, Pole T (Borderline Tuberculoid) or Pole L (Borderline Lepromatous and Lepromatous) of leprosy. Notably, six variants were exclusively found in both clinical poles of leprosy, including m.4158A>G and m.4248T>C in MT-ND1, m.13650C>A, m.13674T>C, m.12705C>T and m.13263A>G in MT-ND5, of which there are no previous reports in the global literature. Our observations reveal a substantial number of mutations among different groups of leprosy, highlighting a diverse range of consequences associated with mutations in genes across these groups. Furthermore, we suggest that the six specific variants exclusively identified in the case group could potentially play a crucial role in leprosy susceptibility and its clinical differentiation. These variants are believed to contribute to the instability and dysregulation of oxidative phosphorylation during the infection, further emphasizing their significance., (© 2024. The Author(s).)

Since the leprosy cases have fallen dramatically, the incidence of leprosy has remained stable over the past years, indicating that multidrug therapy seems unable to eradicate leprosy. More seriously, the emergence of rifampicin-resistant strains also affects the effectiveness of treatment. Immunoprophylaxis was mainly carried out through vaccination with the BCG but also included vaccines such as LepVax and MiP. Meanwhile, it is well known that the infection and pathogenesis largely depend on the host's genetic background and immunity, with the onset of the disease being genetically regulated. The immune process heavily influences the clinical course of the disease. However, the impact of immune processes and genetic regulation of leprosy on pathogenesis and immunological levels is largely unknown. Therefore, we summarize the latest research progress in leprosy treatment, prevention, immunity and gene function. The comprehensive research in these areas will help elucidate the pathogenesis of leprosy and provide a basis for developing leprosy elimination strategies., 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 Li, Ma, Li, Jin, Xu, Li, Wei and Zhang.)

Abstract: Leprosy, an ancient disease, continues to be a public health concern as it remains endemic in several countries. After reaching the elimination target (1/10,000) as a public health problem in 2005 in India, around 1.2 lakh cases have been detected every year over the last decade indicating active transmission of leprosy bacillus (Mycobacterium leprae). Single-nucleotide polymorphisms (SNPs), genomic insertions/deletions and variable-number tandem repeats (VNTRs) have been identified as genetic markers for tracking M. leprae transmission. As the leprosy bacilli cannot be cultured in vitro, molecular testing of M. leprae genotypes is done by polymerase chain reaction-based sequencing which provides a practical alternative for the identification of strains as well as drug resistance-associated mutations. Whole-genome sequencing (WGS) of M. leprae directly from clinical samples has also proven to be an effective tool for identifying genetic variations which can further help refine the molecular epidemiological schemes based on SNPs and VNTRs. However, the WGS data of M. leprae strains from India are scarce, being responsible for a gross under-representation of the genetic diversity of M. leprae strains present in India and need to be addressed suitably. Molecular studies of leprosy can provide better insight into phylogeographic markers to monitor the transmission dynamics and emergence of antimicrobial resistance. An improved understanding of M. leprae transmission is essential to guide efficient leprosy control strategies. Therefore, this review compiles and discusses the current status of molecular epidemiology, genotyping and the potential of genome-wide analysis of M. leprae strains in the Indian context., (Copyright © 2024 Copyright: © 2024 Indian Journal of Medical Research.)

Leprosy and psoriasis rarely coexist, the specific molecular mechanisms underlying their mutual exclusion have not been extensively investigated. This study aimed to reveal the underlying mechanism responsible for the mutual exclusion between psoriasis and leprosy. We obtained leprosy and psoriasis data from ArrayExpress and GEO database. Differential expression analysis was conducted separately on the leprosy and psoriasis using DEseq2. Differentially expressed genes (DEGs) with opposite expression patterns in psoriasis and leprosy were identified, which could potentially involve in their mutual exclusion. Enrichment analysis was performed on these candidate mutually exclusive genes, and a protein-protein interaction (PPI) network was constructed to identify hub genes. The expression of these hub genes was further validated in an external dataset to obtain the critical mutually exclusive genes. Additionally, immune cell infiltration in psoriasis and leprosy was analyzed using single-sample gene set enrichment analysis (ssGSEA), and the correlation between critical mutually exclusive genes and immune cells was also examined. Finally, the expression pattern of critical mutually exclusive genes was evaluated in a single-cell transcriptome dataset. We identified 1098 DEGs in the leprosy dataset and 3839 DEGs in the psoriasis dataset. 48 candidate mutually exclusive genes were identified by taking the intersection. Enrichment analysis revealed that these genes were involved in cholesterol metabolism pathways. Through PPI network analysis, we identified APOE, CYP27A1, FADS1, and SOAT1 as hub genes. APOE, CYP27A1, and SOAT1 were subsequently validated as critical mutually exclusive genes on both internal and external datasets. Analysis of immune cell infiltration indicated higher abundance of 16 immune cell types in psoriasis and leprosy compared to normal controls. The abundance of 6 immune cell types in psoriasis and leprosy positively correlated with the expression levels of APOE and CYP27A1. Single-cell data analysis demonstrated that critical mutually exclusive genes were predominantly expressed in Schwann cells and fibroblasts. This study identified APOE, CYP27A1, and SOAT1 as critical mutually exclusive genes. Cholesterol metabolism pathway illustrated the possible mechanism of the inverse association of psoriasis and leprosy. The findings of this study provide a basis for identifying mechanisms and therapeutic targets for psoriasis., (© 2024. The Author(s).)

Background: In recent years, the mitochondria/immune system interaction has been proposed, so that variants of mitochondrial genome and levels of heteroplasmy might deregulate important metabolic processes in fighting infections, such as leprosy., Methods: We sequenced the whole mitochondrial genome to investigate variants and heteroplasmy levels, considering patients with different clinical forms of leprosy and household contacts. After sequencing, a specific pipeline was used for preparation and bioinformatics analysis to select heteroplasmic variants., Results: We found 116 variants in at least two of the subtypes of the case group (Borderline Tuberculoid, Borderline Lepromatous, Lepromatous), suggesting a possible clinical significance to these variants. Notably, 15 variants were exclusively found in these three clinical forms, of which five variants stand out for being missense (m.3791T > C in MT-ND1, m.5317C > A in MT-ND2, m.8545G > A in MT-ATP8, m.9044T > C in MT-ATP6 and m.15837T > C in MT-CYB). In addition, we found 26 variants shared only by leprosy poles, of which two are characterized as missense (m.4248T > C in MT-ND1 and m.8027G > A in MT-CO2)., Conclusion: We found a significant number of variants and heteroplasmy levels in the leprosy patients from our cohort, as well as six genes that may influence leprosy susceptibility, suggesting for the first time that the mitogenome might be involved with the leprosy process, distinction of clinical forms and severity. Thus, future studies are needed to help understand the genetic consequences of these variants., (© 2023. The Author(s).)

Background: Pentraxin 3 (PTX3) is a soluble pattern recognition receptor that plays a crucial role in modulating the inflammatory response and activating the complement system. Additionally, plasma PTX3 has emerged as a potential biomarker for various infectious diseases. The aim of this study was to evaluate the association of PTX3 gene polymorphisms and PTX3 plasma levels with susceptibility to leprosy and clinical characteristics., Methods: Patients with leprosy from a hyperendemic area in the Northeast Region of Brazil were included. Healthy household contacts and healthy blood donors from the same geographical area were recruited as a control group. The rs1840680 and rs2305619 polymorphisms of PTX3 were determined by real-time PCR. Plasma levels of PTX3 were determined by ELISA., Results: A total of 512 individuals were included. Of these, 273 were patients diagnosed with leprosy; 53 were household contacts, and 186 were healthy blood donors. No association was observed between PTX3 polymorphisms and susceptibility to leprosy or development of leprosy reaction or physical disability. On the other hand, plasma levels of PTX3 were significantly higher in patients with leprosy when compared to household contacts (p = 0.003) or blood donors (p = 0.04). It was also observed that PTX3 levels drop significantly after multidrug therapy (p < 0.0001)., Conclusions: Our results suggest that PTX3 may play an important role in the pathogenesis of leprosy and point to the potential use of this molecule as an infection marker., (© 2023. The Author(s).)

Leprosy is a major health concern and continues to be a source of fear and stigma among people worldwide. Despite remarkable achievements in the treatment, understanding of pathogenesis and transmission, epidemiology of leprosy still remains inadequate. The prolonged incubation period, slow rates of occurrence in those exposed and deceptive clinical presentation pose challenges to develop reliable strategies to stop transmission. Hence, there is a need for improved diagnostics and therapies to prevent mortality caused by leprosy. The objectives of this study are to identify significant genes from protein-protein interactions (PPIs) network of leprosy and to choose the most effective therapeutic targets. Fifty genes related with leprosy were discovered by literature mining. These genes were used to construct a primary network. Leading Eigen Vector method was used to break down the primary network into various sub-networks or communities. It was found that the primary network was divided into many sub-networks at the 6 levels. Seed genes were traced at each level till key regulatory genes were identified. Three seed genes, namely, GNAI3, NOTCH1, and HIF1A, were able to make their way till the final motif stage. These genes along with their interacting partners were considered key regulators of the leprosy network. This study provides leprosy-associated key genes which can lead to improved diagnosis and therapies for leprosy patients.

Peripheral nerves and Schwann cells (SCs) are privileged and protected sites for initial colonization, survival, and spread of leprosy bacillus. Mycobacterium leprae strains that survive multidrug therapy show a metabolic inactivation that subsequently induces the recurrence of typical clinical manifestations of leprosy. Furthermore, the role of the cell wall phenolic glycolipid I (PGL-I) in the M. leprae internalization in SCs and the pathogenicity of M. leprae have been extensively known. This study assessed the infectivity in SCs of recurrent and non-recurrent M. leprae and their possible correlation with the genes involved in the PGL-I biosynthesis. The initial infectivity of non-recurrent strains in SCs was greater (27%) than a recurrent strain (6.5%). In addition, as the trials progressed, the infectivity of the recurrent and non-recurrent strains increased 2.5- and 2.0-fold, respectively; however, the maximum infectivity was displayed by non-recurrent strains at 12 days post-infection. On the other hand, qRT-PCR experiments showed that the transcription of key genes involved in PGL-I biosynthesis in non-recurrent strains was higher and faster (Day 3) than observed in the recurrent strain (Day 7). Thus, the results indicate that the capacity of PGL-I production is diminished in the recurrent strain, possibly affecting the infective capacity of these strains previously subjected to multidrug therapy. The present work opens the need to address more extensive and in-depth studies of the analysis of markers in the clinical isolates that indicate a possible future recurrence.

Introduction: The aim of the present study was to investigate the association between the single nucleotide polymorphism (SNP) rs1927914 A/G in TLR4 gene and the immunological profile of household contacts (HHC) of leprosy patients. Leprosy classification is usually complex and requires the assessment of several clinical and laboratorial features., Methods: Herein, we have applied distinct models of descriptive analysis to explore qualitative/quantitative changes in chemokine and cytokine production in HHC further categorized according to operational classification [HHC(PB) and HHC(MB)] and according to TLR4 SNP., Results and Discussion: Our results showed that M. leprae stimuli induced an outstanding production of chemokines (CXCL8;CCL2; CXCL9; CXCL10) by HHC(PB), while increase levels of pro-inflammatory cytokines (IL-6; TNF; IFN-γ; IL-17) were observed for HHC(MB). Moreover, the analysis of chemokine and cytokine signatures demonstrated that A allele was associated with a prominent soluble mediator secretion (CXCL8; CXCL9; IL-6; TNF; IFN-γ). Data analysis according to TLR4 SNP genotypes further demonstrated that AA and AG were associated with a more prominent secretion of soluble mediators as compared to GG, supporting the clustering of AA and AG genotypes into dominant genetic model. CXCL8, IL-6, TNF and IL-17 displayed distinct profiles in HHC(PB) vs HHC(MB) or AA+AG vs GG genotype. In general, chemokine/cytokine networks analysis showed an overall profile of AA+GA-selective (CXCL9-CXCL10) and GG-selective (CXCL10-IL-6) axis regardless of the operational classification. However, mirrored inverted CCL2-IL-10 axis and a (IFN-γ-IL-2)-selective axis were identified in HHC(MB). CXCL8 presented outstanding performance to classify AA+AG from GG genotypes and HHC(PB) from HHC(MB). TNF and IL-17 presented elevated accuracy to classify AA+AG from GG genotypes and HHC(PB) (low levels) from HHC(MB) (high levels), respectively. Our results highlighted that both factors: i) differential exposure to M. leprae and ii) TLR4 rs1927914 genetic background impact the immune response of HHC. Our main results reinforce the relevance of integrated studies of immunological and genetic biomarkers that may have implications to improve the classification and monitoring of HHC in future 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 © 2023 Cunha, Marçal, Gama, de Oliveira, Pinheiro, Sarno, Brito-de-Sousa, de Souza, Fairley, Valente, Velloso-Rodrigues, Martins-Filho, de Oliveira and Fraga.)

Background: Mycobacterium leprae (slow-growing bacteria) is the etiological agent for leprosy infection, which is a chronic granulomatous disease. Symptoms initiate with the loss of sensation in the affected areas, which can lead to severe injuries, cuts and burns. IRAK2 (interleukin-1 receptor-associated kinases 2) is reported to function in the regulation of the NFκB pathway. The frequency of the IRAK2 polymorphism (rs708035) was unknown in the Pakistani population. Therefore, the study was designed to identify the role of the rs708035 SNP (single nucleotide polymorphism) in susceptibility to leprosy., Methodology: The case-control study was designed, and participants were selected by Ridley-Jopling Classification. Blood samples from healthy individuals and patients were collected after ethical approval. Genomic DNA was extracted for the amplification of selected polymorphisms by tetra-primer amplification refractory mutation system polymerase chain reaction. The desired products were observed via agarose gel (2.5%) electrophoresis followed by data analysis using bioinformatics tools (SNP Stats and SHEsis) and statistical tests (odds ratio, OR, and chi square)., Results: The study revealed that the mutant genotype (TT) was found to be frequent among cases (22.80%) in comparison with the controls (1.66%). The SNP rs708035 was significantly associated with the progression of leprosy (χ 2  = 17.62, p < 0.0001). The targeted SNP significantly increases the risk of leprosy 2.3 times (OR = 2.3119, 95% CI 1.2729-4.1989, p < 0.01). The genetic model also confirms the significant association of the A/T genotype with leprosy in the over-dominant model (OR = 2.83, 95% CI 1.16-6.89, p < 0.001)., Conclusions: The study revealed a significant association of the targeted SNP with leprosy and provided baseline data regarding the association of rs708035. The current research could be utilized for the preparation of biomarkers by considering a larger sample size., Highlights: The patients suffering from leprosy faced various comorbidities, including hypertension and diabetes. The study reports for the first time a significant association of interleukin 1 receptor associated kinases 2 (IRAK2) single nucleotide polymorphism (SNP) rs708035 among the Pakistani population (Karachi). The current study provides baseline data to develop diagnostic biomarkers for early detection of leprosy., (© 2023 John Wiley & Sons, Ltd.)

Leprosy, caused by Mycobacterium leprae, rarely affects children younger than 5 years. Here, we studied a multiplex leprosy family that included monozygotic twins aged 22 months suffering from paucibacillary leprosy. Whole genome sequencing identified three amino acid mutations previously associated with Crohn's disease and Parkinson's disease as candidate variants for early onset leprosy: LRRK2 N551K, R1398H and NOD2 R702W. In genome-edited macrophages, we demonstrated that cells expressing the LRRK2 mutations displayed reduced apoptosis activity following mycobacterial challenge independently of NOD2. However, employing co-immunoprecipitation and confocal microscopy we showed that LRRK2 and NOD2 proteins interacted in RAW cells and monocyte-derived macrophages, and that this interaction was substantially reduced for the NOD2 R702W mutation. Moreover, we observed a joint effect of LRRK2 and NOD2 variants on Bacillus Calmette-Guérin (BCG)-induced respiratory burst, NF-κB activation and cytokine/chemokine secretion with a strong impact for the genotypes found in the twins consistent with a role of the identified mutations in the development of early onset leprosy., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Dallmann-Sauer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Leprosy is a chronic infectious disease caused by Mycobacterium leprae. The development of leprosy involves several factors, including the causative agent, the individual host's immune response, environmental factors, and the genetic background of the host. Specifically, the host's innate immune response, encoded by genes, determines their susceptibility to developing leprosy post-infection. Polymorphic variants in the nucleotide-binding oligomerization domain 2 (NOD2) gene are associated with leprosy among populations in a variety of endemic areas around the world. Colombia, a country located in the tropical zone, has several leprosy-endemic regions, including Norte de Santander. The aim of this study was to analyze the rs7194886, rs2111234, rs3135499, and rs8057341 single nucleotide polymorphisms (SNPs) in the NOD2 gene using a case-control study to determine whether they confer greater or lesser susceptibility to the development of leprosy., Methodology: The TaqMan qPCR amplification system was used for SNPs detection., Findings: An association between the A-rs8057341 SNP (p = 0,006286) and resistance to leprosy was found. However, the rs3135499 (p = 0,9063) and rs2111234 (p = 0.1492) were not found to be associated with leprosy susceptibility. In addition, the rs7194886 SNP was not found to be in Hardy-Weinberg equilibrium (HWE) in the study population. The GAG haplotype, consisting of SNPs rs2111234-G, rs3135499-A, and rs8057341G, acts as a susceptibility factor for the development of leprosy in women. SNPs rs3135499 and rs8057341 are functionally related to decreased NOD2 expression according to an in-silico analysis., Conclusions: The SNPs rs8057341-A was related with resistance to leprosy and the haplotype rs2111234-G, rs3135499-A and rs8057341-G SNPs was related with susceptibility in the Norte de Santander Colombia, studied population., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Bustos et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The control of infections by the vertebrate adaptive immune system requires careful modulation to optimize defense and minimize harm to the host. The Fc receptor-like ( FCRL ) genes encode immunoregulatory molecules homologous to the receptors for the Fc portion of immunoglobulin (FCR). To date, nine different genes ( FCRL1-6 , FCRLA , FCRLB and FCRLS ) have been identified in mammalian organisms. FCRL6 is located at a separate chromosomal position from the FCRL1-5 locus, has conserved synteny in mammals and is situated between the SLAMF8 and DUSP23 genes. Here, we show that this three gene block underwent repeated duplication in Dasypus novemcinctus (nine-banded armadillo) resulting in six FCRL6 copies, of which five appear functional. Among 21 mammalian genomes analyzed, this expansion was unique to D. novemcinctus . Ig-like domains that derive from the five clustered FCRL6 functional gene copies show high structural conservation and sequence identity. However, the presence of multiple non-synonymous amino acid changes that would diversify individual receptor function has led to the hypothesis that FCRL6 endured subfunctionalization during evolution in D. novemcinctus . Interestingly, D. novemcinctus is noteworthy for its natural resistance to the Mycobacterium leprae pathogen that causes leprosy. Because FCRL6 is chiefly expressed by cytotoxic T and NK cells, which are important in cellular defense responses against M. leprae , we speculate that FCRL6 subfunctionalization could be relevant for the adaptation of D. novemcinctus to leprosy. These findings highlight the species-specific diversification of FCRL family members and the genetic complexity underlying evolving multigene families critical for modulating adaptive immune protection.

Genome-wide association studies (GWAS) of Crohn's disease (CD) in European and leprosy in Chinese population have shown that CD and leprosy share genetic risk loci. As these shared loci were identified through cross-comparisons across different ethnic populations, we hypothesized that meta-analysis of GWAS on CD and leprosy in East Asian populations would increase power to identify additional shared loci. We performed a cross-disease meta-analysis of GWAS data from CD (1621 cases and 4419 controls) and leprosy (2901 cases 3801 controls) followed by replication in additional datasets comprising 738 CD cases and 488 controls and 842 leprosy cases and 925 controls. We identified one novel locus at 7p22.3, rs77992257 in intron 2 of ADAP1, shared between CD and leprosy with genome-wide significance (P = 3.80 × 10-11) and confirmed 10 previously established loci in both diseases: IL23R, IL18RAP, IL12B, RIPK2, TNFSF15, ZNF365-EGR2, CCDC88B, LACC1, IL27, NOD2. Phenotype variance explained by the polygenic risk scores derived from Chinese leprosy data explained up to 5.28% of variance of Korean CD, supporting similar genetic structures between the two diseases. Although CD and leprosy shared a substantial number of genetic susceptibility loci in East Asians, the majority of shared susceptibility loci showed allelic effects in the opposite direction. Investigation of the genetic correlation using cross-trait linkage disequilibrium score regression also showed a negative genetic correlation between CD and leprosy (rg [SE] = -0.40[0.13], P = 2.6 × 10-3). These observations implicate the possibility that CD might be caused by hyper-sensitive reactions toward pathogenic stimuli., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Dapsone (DDS), Rifampicin (RIF) and Ofloxacin (OFL) are drugs recommended by the World Health Organization (WHO) for the treatment of leprosy. In the context of leprosy, resistance to these drugs occurs mainly due to mutations in the target genes (Folp1, RpoB and GyrA). It is important to monitor antimicrobial resistance in patients with leprosy. Therefore, we performed a meta-analysis of drug resistance in Mycobacterium leprae and the mutational profile of the target genes. In this paper, we limited the study period to May 2022 and searched PubMed, Web of Science (WOS), Scopus, and Embase databases for identified studies. Two independent reviewers extracted the study data. Mutation and drug-resistance rates were estimated in Stata 16.0. The results demonstrated that the drug-resistance rate was 10.18% (95% CI: 7.85-12.51). Subgroup analysis showed the highest resistance rate was in the Western Pacific region (17.05%, 95% CI:1.80 to 13.78), and it was higher after 2009 than before [(11.39%, 7.46-15.33) vs. 6.59% (3.66-9.53)]. We can conclude that the rate among new cases (7.25%, 95% CI: 4.65-9.84) was lower than the relapsed (14.26%, 95 CI%: 9.82-18.71). Mutation rates of Folp1, RpoB and GyrA were 4.40% (95% CI: 3.02-5.77), 3.66% (95% CI: 2.41-4.90) and 1.28% (95% CI: 0.87-1.71) respectively, while the rate for polygenes mutation was 1.73% (0.83-2.63). For further analysis, we used 368 drug-resistant strains as research subjects and found that codons (Ser, Pro, Ala) on RpoB, Folp1 and GyrA are the most common mutation sites in the determining region (DRDR). In addition, the most common substitution patterns of Folp1, RpoB, and GyrA are Pro→Leu, Ser→Leu, and Ala→Val. This study found that a higher proportion of patients has developed resistance to these drugs, and the rate has increased since 2009, which continue to pose a challenge to clinicians. In addition, the amino acid alterations in the sequence of the DRDR regions and the substitution patterns mentioned in the study also provide new ideas for clinical treatment options.

Leprosy is a chronic infection of the skin and peripheral nerves caused by Mycobacterium leprae. Despite recent improvements in disease control, leprosy remains an important cause of infectious disability globally. Large-scale genetic association studies in Chinese, Vietnamese and Indian populations have identified over 30 susceptibility loci for leprosy. There is a significant burden of leprosy in Africa, however it is uncertain whether the findings of published genetic association studies are generalizable to African populations. To address this, we conducted a genome-wide association study (GWAS) of leprosy in Malawian (327 cases, 436 controls) and Malian (247 cases, 368 controls) individuals. In that analysis, we replicated four risk loci previously reported in China, Vietnam and India; MHC Class I and II, LACC1 and SLC29A3. We further identified a novel leprosy susceptibility locus at 10q24 (rs2015583; combined p = 8.81 × 10-9; OR = 0.51 [95% CI 0.40 - 0.64]). Using publicly-available data we characterise regulatory activity at this locus, identifying ACTR1A as a candidate mediator of leprosy risk. This locus shows evidence of recent positive selection and demonstrates pleiotropy with established risk loci for inflammatory bowel disease and childhood-onset asthma. A shared genetic architecture for leprosy and inflammatory bowel disease has been previously described. We expand on this, strengthening the hypothesis that selection pressure driven by leprosy has shaped the evolution of autoimmune and atopic disease in modern populations. More broadly, our data highlights the importance of defining the genetic architecture of disease across genetically diverse populations, and that disease insights derived from GWAS in one population may not translate to all affected populations., Competing Interests: The authors have declared that no competing interests exist.

Leprosy is a chronic neurodermatological disease caused by the bacillus Mycobacterium leprae . Recent studies show that SNPs in genes related to miRNAs have been associated with several diseases in different populations. This study aimed to evaluate the association of twenty-five SNPs in genes encoding miRNAs related to biological processes and immune response with susceptibility to leprosy and its polar forms paucibacillary and multibacillary in the Brazilian Amazon. A total of 114 leprosy patients and 71 household contacts were included in this study. Genotyping was performed using TaqMan Open Array Genotyping. Ancestry-informative markers were used to estimate individual proportions of case and control groups. The SNP rs2505901 ( pre-miR938 ) was associated with protection against the development of paucibacillary leprosy, while the SNPs rs639174 ( DROSHA ), rs636832 ( AGO1 ), and rs4143815 ( miR570 ) were associated with protection against the development of multibacillary leprosy. In contrast, the SNPs rs10739971 ( pri-let-7a1 ), rs12904 ( miR200C ), and rs2168518 ( miR4513 ) are associated with the development of the paucibacillary leprosy. The rs10739971 ( pri-let-7a1 ) polymorphism was associated with the development of leprosy, while rs2910164 ( miR146A ) and rs10035440 ( DROSHA ) was significantly associated with an increased risk of developing multibacillary leprosy.

In humans, mitochondria play key roles in the regulation of cellular functions, such as the regulation of the innate immune response and are targets of several pathogenic viruses and bacteria. Mycobacteria are intracellular pathogens that infect cells important to the immune system of organisms and target mitochondria to meet their energy demands. In this review, we discuss the main mechanisms by which mitochondria regulate the innate immune response of humans to mycobacterial infection, especially those that cause tuberculosis and leprosy. Notably, the importance of mitochondrial haplogroups and ancestry studies for mycobacterial diseases is also discussed.

Background: Leprosy, caused by Mycobacterium leprae, is a public health problem in Brazil that affects peripheral nerves, resulting in physical disabilities. During host-pathogen interactions, the immune response determines leprosy outcomes from a localised (paucibacillary) form to a disseminated (multibacillary) form. The recognition of M. leprae involves the DC-SIGN receptor, which is present on the dendritic cells (DCs) and participates in immune activation., Objectives: To evaluate the association of polymorphisms in the promoter region of the gene encoding DC-SIGN (CD209) and the clinical form of leprosy, and to investigate its functional effects., Methods: The study population included 406 leprosy patients from an endemic area in Brazil [310 multibacillary (MB); 96 paucibacillary (PB)]. A functional evaluation based on the effects of the single nucleotide variant (SNV) associated with PB leprosy on the specific immune response was also performed., Results: The GA genotype and the presence of the A allele of rs735240 (-939G>A) were associated with PB leprosy [OR: 2.09 (1.18-3.69) and 1.84 (1.07-3.14), respectively]. Carriers of the A allele showed reduced expression of CD209 and TGF-β1 in leprosy lesions in comparison with individuals with GG genotype, in addition to a higher response to the Mitsuda test., Conclusion: These data suggest that rs735240 influences the immune response against M. leprae and clinical presentation of leprosy.

Mycobacterium leprae, the causative organism of leprosy, harbors many antigenic proteins, and one such protein is the 18-kDa antigen. This protein belongs to the small heat shock protein family and is commonly known as HSP18. Its chaperone function plays an important role in the growth and survival of M. leprae inside infected hosts. HSP18/18-kDa antigen is often used as a diagnostic marker for determining the efficacy of multidrug therapy (MDT) in leprosy. However, whether MDT drugs (dapsone, clofazimine, and rifampicin) do interact with HSP18 and how these interactions affect its structure and chaperone function is still unclear. Here, we report evidence of HSP18-dapsone/clofazimine/rifampicin interaction and its impact on the structure and chaperone function of HSP18. These three drugs interact efficiently with HSP18 (having submicromolar binding affinity) with 1 : 1 stoichiometry. Binding of these MDT drugs to the 'α-crystallin domain' of HSP18 alters its secondary structure and tryptophan micro-environment. Furthermore, surface hydrophobicity, oligomeric size, and thermostability of the protein are reduced upon interaction with these three drugs. Eventually, all these structural alterations synergistically decrease the chaperone function of HSP18. Interestingly, the effect of rifampicin on the structure, stability, and chaperone function of this mycobacterial small heat shock protein is more pronounced than the other two MDT drugs. This reduction in the chaperone function of HSP18 may additionally abate M. leprae survivability during multidrug treatment. Altogether, this study provides a possible foundation for rational designing and development of suitable HSP18 inhibitors in the context of effective treatment of leprosy., (© 2021 Federation of European Biochemical Societies.)

Leprosy is the second most prevalent mycobacterial disease globally. Despite the existence of an effective therapy, leprosy incidence has consistently remained above 200,000 cases per year since 2010. Numerous host genetic factors have been identified for leprosy that contribute to the persistently high case numbers. In the past decade, genetic epidemiology approaches, including genome-wide association studies (GWAS), identified more than 30 loci contributing to leprosy susceptibility. However, GWAS loci commonly encompass multiple genes, which poses a challenge to define causal candidates for each locus. To address this problem, we hypothesized that genes contributing to leprosy susceptibility differ in their frequencies of rare protein-altering variants between cases and controls. Using deep resequencing we assessed protein-coding variants for 34 genes located in GWAS or linkage loci in 555 Vietnamese leprosy cases and 500 healthy controls. We observed 234 nonsynonymous mutations in the targeted genes. A significant depletion of protein-altering variants was detected for the IL18R1 and BCL10 genes in leprosy cases. The IL18R1 gene is clustered with IL18RAP and IL1RL1 in the leprosy GWAS locus on chromosome 2q12.1. Moreover, in a recent GWAS we identified an HLA-independent signal of association with leprosy on chromosome 6p21. Here, we report amino acid changes in the CDSN and PSORS1C2 genes depleted in leprosy cases, indicating them as candidate genes in the chromosome 6p21 locus. Our results show that deep resequencing can identify leprosy candidate susceptibility genes that had been missed by classic linkage and association approaches., Competing Interests: The authors have declared that no competing interests exist.

Background: Brazil remains endemic for infection by the human immunodeficiency virus (HIV) and leprosy, having a major impact on public health and the life quality of affected patients. Although the relevance of this co-infection is recognized, several aspects, such as the immune response, are not yet fully understood. The objective of this study was to investigate the expression of FOXP3+ Treg cells in leprosy skin lesions and to correlate their clinical forms, laboratory characteristics (CD4, CD8, and CV), and the immune reconstitution syndrome in HIV-leprosy co-infection., Methodology/principal Findings: An observational, cross-sectional, and analytical study was carried out comparing four groups of patients: those with concomitant diagnosis of leprosy and HIV infection without a leprosy reaction, those with leprosy and HIV co-infection patients with a reverse reaction (RR), those with leprosy without HIV and without reaction, and those with leprosywithout HIV and with RR. The patients were diagnosed at a dermatology outpatient clinic located in Belém, Pará, Brazil, from 2003 to 2017. In the sample studied, there was a positive correlation between FOXP3+ cell density and viral load, negative correlation with blood CD4+ (not statistically significant), significant positive correlation in CD8 count in patients with leprosy reaction, and positive relationship in patients with IRIS. The density of cells expressing FOXP3 was higher in the BL/LL forms in patients without HIV, although the difference was not statistically significant. However, the cell mean was higher in the TT/BT forms in patients co-infected with leprosy and HIV, showing contradictory results., Conclusions/significance: These findings support that higher activity of the HIV may stimulate or result in a higher expression of FOXP3-Tregs and that they may be involved in active immunosuppression observed at the infection site at the tissue level. This supports the need to expand studies on FOXP3+ Treg cells in co-infected patients., Competing Interests: The authors have declared that no competing interests exist.

Transcriptional profiling is a powerful tool to investigate and detect human diseases. In this study, we used bulk RNA-sequencing (RNA-Seq) to compare the transcriptomes in skin lesions of leprosy patients or controls affected by other dermal conditions such as granuloma annulare, a confounder for paucibacillary leprosy. We identified five genes capable of accurately distinguishing multibacillary and paucibacillary leprosy from other skin conditions. Indoleamine 2,3-dioxygenase 1 (IDO1) expression alone was highly discriminatory, followed by TLR10, BLK, CD38, and SLAMF7, whereas the HS3ST2 and CD40LG mRNA separated multi- and paucibacillary leprosy. Finally, from the main differentially expressed genes (DEG) and enriched pathways, we conclude that paucibacillary disease is characterized by epithelioid transformation and granuloma formation, with an exacerbated cellular immune response, while multibacillary leprosy features epithelial-mesenchymal transition with phagocytic and lipid biogenesis patterns in the skin. These findings will help catalyze the development of better diagnostic tools and potential host-based therapeutic interventions. Finally, our data may help elucidate host-pathogen interplay driving disease clinical manifestations., Competing Interests: The authors have declared that no competing interests exist.

Background: Hansen's disease (leprosy), widespread in medieval Europe, is today mainly prevalent in tropical and subtropical regions with around 200,000 new cases reported annually. Despite its long history and appearance in historical records, its origins and past dissemination patterns are still widely unknown. Applying ancient DNA approaches to its major causative agent, Mycobacterium leprae, can significantly improve our understanding of the disease's complex history. Previous studies have identified a high genetic continuity of the pathogen over the last 1500 years and the existence of at least four M. leprae lineages in some parts of Europe since the Early Medieval period., Results: Here, we reconstructed 19 ancient M. leprae genomes to further investigate M. leprae's genetic variation in Europe, with a dedicated focus on bacterial genomes from previously unstudied regions (Belarus, Iberia, Russia, Scotland), from multiple sites in a single region (Cambridgeshire, England), and from two Iberian leprosaria. Overall, our data confirm the existence of similar phylogeographic patterns across Europe, including high diversity in leprosaria. Further, we identified a new genotype in Belarus. By doubling the number of complete ancient M. leprae genomes, our results improve our knowledge of the past phylogeography of M. leprae and reveal a particularly high M. leprae diversity in European medieval leprosaria., Conclusions: Our findings allow us to detect similar patterns of strain diversity across Europe with branch 3 as the most common branch and the leprosaria as centers for high diversity. The higher resolution of our phylogeny tree also refined our understanding of the interspecies transfer between red squirrels and humans pointing to a late antique/early medieval transmission. Furthermore, with our new estimates on the past population diversity of M. leprae, we gained first insights into the disease's global history in relation to major historic events such as the Roman expansion or the beginning of the regular transatlantic long distance trade. In summary, our findings highlight how studying ancient M. leprae genomes worldwide improves our understanding of leprosy's global history and can contribute to current models of M. leprae's worldwide dissemination, including interspecies transmissions., (© 2021. The Author(s).)

Leprosy reactional episodes are acute inflammatory events that may occur during the clinical course of the disease. Type 1 reaction (T1R) is associated with an increase in neural damage, and the understanding of the molecular pathways related to T1R onset is pivotal for the development of strategies that may effectively control the reaction. Interferon-gamma (IFN- γ ) is a key cytokine associated with T1R onset and is also associated with autophagy induction. Here, we evaluated the modulation of the autophagy pathway in Mycobacterium leprae -stimulated cells in the presence or absence of IFN- γ . We observed that IFN- γ treatment promoted autophagy activation and increased the expression of genes related to the formation of phagosomes, autophagy regulation and function, or lysosomal pathways in M. leprae -stimulated cells. IFN- γ increased interleukin (IL)-15 secretion in M. leprae -stimulated THP-1 cells in a process associated with autophagy activation. We also observed higher IL15 gene expression in multibacillary (MB) patients who later developed T1R during clinical follow-up when compared to MB patients who did not develop the episode. By overlapping gene expression patterns, we observed 13 common elements shared between T1R skin lesion cells and THP-1 cells stimulated with both M. leprae and IFN- γ . Among these genes, the autophagy regulator Translocated Promoter Region, Nuclear Basket Protein ( TPR ) was significantly increased in T1R cells when compared with non-reactional MB cells. Overall, our results indicate that IFN- γ may induce a TPR-mediated autophagy transcriptional program in M. leprae -stimulated cells similar to that observed in skin cells during T1R by a pathway that involves IL-15 production, suggesting the involvement of this cytokine in the pathogenesis of T1R.

The transmission and evolution of leprosy depends on several aspects, including immunological and genetic factors of the host, as well as genetic factors of Mycobacterium leprae. The present study evaluated the association of single nucleotide polymorphisms (SNPs) on the FokI (rs2228570), TaqI (rs731236), ApaI (rs7975232) regions of the vitamin D receptor (VDR) gene with leprosy. A total of 405 individuals were evaluated, composed by groups of 100 multibacillary (MB) and 57 paucibacillary (PB) patients, and 248 healthy contacts. Blood samples were collected from patients and contacts. The genotyping was performed by sequencing of the interest regions. The alleles of the studied SNPs, and SNP FokI genotypes, were not associated with leprosy. For the SNP on TaqI region, the relationship between the tt genotype, and for the SNP ApaI, the AA genotype, revealed an association with susceptibility to MB form, while Aa genotype with protection. The extended genotypes AaTT and AaTt of ApaI and TaqI were associated with protection against MB form. Further studies analyzing the expression of the VDR gene and the correlation with its SNPs might help to clarify the role of polymorphisms on the immune response in leprosy., (© 2021 The Author(s).)

Across Europe, the genetics of the Chalcolithic/Bronze Age transition is increasingly characterized in terms of an influx of Steppe-related ancestry. The effect of this major shift on the genetic structure of populations in the Italian Peninsula remains underexplored. Here, genome-wide shotgun data for 22 individuals from commingled cave and single burials in Northeastern and Central Italy dated between 3200 and 1500 BCE provide the first genomic characterization of Bronze Age individuals (n = 8; 0.001-1.2× coverage) from the central Italian Peninsula, filling a gap in the literature between 1950 and 1500 BCE. Our study confirms a diversity of ancestry components during the Chalcolithic and the arrival of Steppe-related ancestry in the central Italian Peninsula as early as 1600 BCE, with this ancestry component increasing through time. We detect close patrilineal kinship in the burial patterns of Chalcolithic commingled cave burials and a shift away from this in the Bronze Age (2200-900 BCE) along with lowered runs of homozygosity, which may reflect larger changes in population structure. Finally, we find no evidence that the arrival of Steppe-related ancestry in Central Italy directly led to changes in frequency of 115 phenotypes present in the dataset, rather that the post-Roman Imperial period had a stronger influence, particularly on the frequency of variants associated with protection against Hansen's disease (leprosy). Our study provides a closer look at local dynamics of demography and phenotypic shifts as they occurred as part of a broader phenomenon of widespread admixture during the Chalcolithic/Bronze Age transition., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: There is a high incidence of leprosy among house-contacts compared with the general population. We aimed to establish a predictive model using these genetic factors along with epidemiological factors to predict leprosy risk of leprosy household contacts (HHCs)., Methods: Weighted genetic risk score (wGRS) encompassing genome wide association studies (GWAS) variants and five non-genetic factors were examined in a case-control design associated with leprosy risk including 589 cases and 647 controls from leprosy HHCs. We constructed a risk prediction nomogram and evaluated its performance by concordance index (C-index) and calibration curve. The results were validated using bootstrap resampling with 1000 resamples and a prospective design including 1100 HHCs of leprosy patients., Finding: The C-index for the risk model was 0·792 (95% confidence interval [CI] 0·768-0·817), and was confirmed to be 0·780 through bootstrapping validation. The calibration curve for the probability of leprosy showed good agreement between the prediction of the nomogram and actual observation. HHCs were then divided into the low-risk group (nomogram score ≤ 81) and the high-risk group (nomogram score > 81). In prospective analysis, 12 of 1100 participants had leprosy during 63 months' follow-up. We generated the nomogram for leprosy in the validation cohort (C-index 0·773 [95%CI 0·658-0·888], sensitivity75·0%, specificity 66·8%). Interpretation The nomogram achieved an effective prediction of leprosy in HHCs. Using the model, the risk of an individual contact developing leprosy can be determined, which can lead to a rational preventive choice for tracing higher-risk leprosy contacts., Funding: The ministry of health of China, ministry of science and technology of China, Chinese academy of medical sciences, Jiangsu provincial department of science and technology, Nanjing municipal science and technology bureau., Competing Interests: Declaration of Competing Interest All authors declare that they have no conflicts of interest., (Copyright © 2021. Published by Elsevier B.V.)

Background: Leprosy, a chronic infectious disease caused by Mycobacterium leprae, is often late- or misdiagnosed leading to irreversible disabilities. Blood transcriptomic biomarkers that prospectively predict those who progress to leprosy (progressors) would allow early diagnosis, better treatment outcomes and facilitate interventions aimed at stopping bacterial transmission. To identify potential risk signatures of leprosy, we collected whole blood of household contacts (HC, n=5,352) of leprosy patients, including individuals who were diagnosed with leprosy 4-61 months after sample collection., Methods: We investigated differential gene expression (DGE) by RNA-Seq between progressors before presence of symptoms (n=40) and HC (n=40), as well as longitudinal DGE within each progressor. A prospective leprosy signature was identified using a machine learning approach (Random Forest) and validated using reverse transcription quantitative PCR (RT-qPCR)., Findings: Although no significant intra-individual longitudinal variation within leprosy progressors was identified, 1,613 genes were differentially expressed in progressors before diagnosis compared to HC. We identified a 13-gene prospective risk signature with an Area Under the Curve (AUC) of 95.2%. Validation of this RNA-Seq signature in an additional set of progressors (n=43) and HC (n=43) by RT-qPCR, resulted in a final 4-gene signature, designated RISK4LEP (MT-ND2, REX1BD, TPGS1, UBC) (AUC=86.4%)., Interpretation: This study identifies for the first time a prospective transcriptional risk signature in blood predicting development of leprosy 4 to 61 months before clinical diagnosis. Assessment of this signature in contacts of leprosy patients can function as an adjunct diagnostic tool to target implementation of interventions to restrain leprosy development., Funding: This study was supported by R2STOP Research grant, the Order of Malta-Grants-for-Leprosy-Research, the Q.M. Gastmann-Wichers Foundation and the Leprosy Research Initiative (LRI) together with the Turing Foundation (ILEP# 702.02.73 and # 703.15.07)., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interests., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Previous genotyping-based assays have identified non-coding variants of several interleukins (ILs) being associated with genetic susceptibility to leprosy. However, understanding of the involvement of coding variants within all IL family genes in leprosy was still limited. To obtain the full mutation spectrum of all ILs in leprosy, we performed a targeted deep sequencing of coding regions of 58 ILs genes in 798 leprosy patients (age 56.2 ± 14.4; female 31.5%) and 990 healthy controls (age 38.1 ± 14.0; female 44.3%) from Yunnan, Southwest China. mRNA expression alterations of ILs in leprosy skin lesions or in response to M. leprae treatment were estimated by using publicly available expression datasets. Two coding variants in IL27 (rs17855750, p.S59A, p = 4.02 × 10 -8 , odds ratio [OR] = 1.748) and IL1RN (rs45507693, p.A106T, p = 1.45 × 10 -5 , OR = 3.629) were significantly associated with leprosy risk. mRNA levels of IL27 and IL1RN were upregulated in whole blood cells after M. leprae stimulation. These data showed that IL27 and IL1RN are leprosy risk genes. Further functional study is required for characterizing the exact role of ILs in leprosy., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Competing Interests: Declaration of Competing Interest The author has no conflicts of interest to disclose.

This study aimed at verifying the relationship between the polymorphisms of the cytokines tumor necrosis factor-alpha (TNF-α) -308 G → A (rs1800629); interferon gamma (IFN-γ) +874 T → A (rs2430561); transforming growth factor-beta (TGF-β) códon 10 (rs1982073) and códon 25 (rs1800471); interleukin (IL)-6 - 174 G → C (rs180079) and IL-10 - 1082 A→T (rs1800896); -819 C → T (rs1800871); -592 A→C (rs1800872); and leprosy. Blood samples were analyzed from 106 individuals, of whom 24 were paucibacillary (PB), 28 were multibacillary (MB), and 54 were patient contacts. Analysis of cytokine polymorphisms was typified by the polymerase chain reaction technique. For TGF-β +869 T → C and +915 G→C, a tendency to associate the presence of the C allele at codon 10 with leprosy was demonstrated, with the T allele being most frequently found in the CCOSI ( P  = 0.056). For the polymorphisms IL-10 - 1082 A→T, -819 C→T, and -592 A→C, we found an association of the GCC/GCC genotype with the susceptibility to the disease and the A allele at position 1082 with the leprosy protection. Greater predominance was found of ACC/ATA (31.3%) and GCC/ATA (37.5%) ( P  = 0.03) and the A allele at position -1082 (76.85%) ( P  = 0.043) in the CCOSI groups, whereas the GCC/GCC was found in the MB group (22.2%) ( P  = 0.05). For the other cytokines's single-nucleotide polymorphisms, there were no associations with susceptibility to leprosy. These results are limited by sample size, may not be conclusive, and will need further confirmation in a larger cohort.

Thousands of leprosy patients not only suffer from physical deformities, but also either have or have had hepatitis B virus (HBV) coinfection. Polymorphisms of the complement system modulate susceptibility to leprosy, but genetic susceptibility to past or present HBV infection is unknown. We used sequencing and multiplex sequence-specific PCR to genotype 72 polymorphisms of seven genes ( MBL2 , FCN1, FCN2, FCN3, MASP1, MASP2, C3 ) encoding components of the lectin pathway, and two genes encoding complement receptors ( CR1, VSIG4 ) in 190 patients, of which 74 were positive for HBsAg and/or anti-HBc (HBV+, 93.2% with a resolved infection) and 116 lepromatous patients, and 408 HBV-blood donors. In addition, we tested for levels of proteins of the lectin pathway. We found no difference between serum concentrations of mannan-binding lectin (MBL), MBL-associated serine proteins (MASP-1, MASP-2, MASP-3, MAp44), ficolin-3 (FCN-3), soluble complement receptor 1 (sCR1) and MBL mediated C4 activation, measured by ELISA or TRIFMA in up to 167 HBV+ and HBV- patients. Haplotypes lowering protein levels or encoding dysfunctional proteins increased susceptibility to HBV infection: MBL2*LYQC (OR = 3.4, p = 0.02), MASP1*AC&#95;CC (OR = 4.0, p = 0.015) and MASP2*1C2-l (OR = 5.4, p = 0.03). Conversely, FCN1*3C2 haplotype, associated with higher gene expression, was protective (OR = 0.56, P = 0.033). Other haplotypes associated with HBV susceptibility were: MASP2*2B1-i (OR = 19.25, P = 0.003), CR1*3A (OR = 2.65, P = 0.011) and VSIG4*TGGRCG (OR = 12.55, P = 0.014). Some polymorphisms in ficolin genes associated with lower protein levels increased susceptibility to leprosy/HBV infection: FCN*1 (OR = 1.66, P = 0.029), FCN2*GGGCAC (OR = 6.73, P = 0.008), and FCN3*del&#95;del&#95;C (OR = 12.54, P = 0.037), and to lepromatous disease/HBV infection: FCN2*TA (OR = 2.5, P = 0.009), whereas FCN2*MAG was associated with increased FCN-2 expression and resistance against coinfection (OR = 0.29, P = 0.026). These associations were independent of demographic factors and did not increase susceptibility to leprosy per se , except MASP2*1C2-l . Associations for FCN2, FCN3, MASP1, MASP2 , and VSIG4 variants were also independent of each other. In conclusion, polymorphisms compromising activation of the lectin pathway of complement increase susceptibility to HBV infection, with ficolin polymorphisms playing a major role in modulating the susceptibility among leprosy patients., 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 Boldt, Oliveira-Toré, Kretzschmar, Weinschutz Mendes, Stinghen, Andrade, Bumiller-Bini, Gonçalves, Braga, Stahlke, Velavan, Thiel and de Messias-Reason.)

Although skin is the primary affected organ in Leprosy, the role of the skin microbiome in its pathogenesis is not well understood. Recent reports have shown that skin of leprosy patients (LP) harbours perturbed microbiota which grants inflammation and disease progression. Herein, we present the results of nested Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) which was initially performed for investigating the diversity of bacterial communities from lesional skin (LS) and non-lesional skin (NLS) sites of LP (n = 11). Further, we performed comprehensive analysis of 16S rRNA profiles corresponding to skin samples from participants (n = 90) located in two geographical locations i.e. Hyderabad and Miraj in India. The genus Staphylococcus was observed to be one of the representative bacteria characterizing healthy controls (HC; n = 30), which in contrast was underrepresented in skin microbiota of LP. Taxa affiliated to phyla Firmicutes and Proteobacteria were found to be signatures of HC and LS, respectively. Observed diversity level changes, shifts in core microbiota, and community network structure support the evident dysbiosis in normal skin microbiota due to leprosy. Insights obtained indicate the need for exploring skin microbiota modulation as a potential therapeutic option for leprosy.

Leprosy is an infectious disease caused by Mycobacterium leprae that affects the skin and nerves. The nerve damage in leprosy may be related to alterations in transcriptional factors, such as Krox-20, Oct-6, Sox-10. Thirty skin biopsies in leprosy patients and 15 non-leprosy skin biopsies were evaluated using RT-qPCR to assess Krox-20, Oct-6, and Sox-10 and these data was related with S-100 immunohistochemistry. Changes in gene expression were observed in the skin and dermal nerves of leprosy patients in Oct-6 and Sox-10. When comparing Oct-6 with S-100 IHC as diagnostic tests for leprosy, Oct-6 showed a sensitivity of 73.3%, and specificity of 100%, while S-100 IHC showed a sensitivity of 96.6% and specificity of 100%. Our data suggest Oct-6 could be an auxiliary biomarker specific to detecting changes in dermal nerves in leprosy and thus useful to health workers and pathologists with no expertise to observe nerve injuries in leprosy., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Leprosy is a prevalent disease in Brazil, which ranks as the country with the second highest number of cases in the world. The disease manifests in a spectrum of forms, and genetic differences in the host can help to elucidate the immunopathogenesis. For a better understanding of MICA association with leprosy, we performed a case-control and a family-based study in two endemic populations in Brazil. MICA and HLA-B alleles were evaluated in 409 leprosy patients and in 419 healthy contacts by PCR-SSOP-Luminex-based technology. In the familial study, analysis of 46 families was completed by direct sequencing of all exons and 3'/5'untranslated regions, using the Ilumina MiSeq platform. All data were collected between 2006 and 2009. Statistical analysis was performed using the Chi-square or Fisher's exact test together with a multivariate analysis. Family-based association was assessed by transmission disequilibrium test (TDT) software FBAT 2.0.4. We found associations between the haplotype MICA*002-HLA-B*35 with leprosy in both the per se and the multibacillary (MB) forms when compared to healthy contacts. The MICA allele *008 was associated with the clinical forms of paucibacillary (PB). Additionally, MICA*029 was associated with the clinical forms of MB. The association of MICA*029 allele (MICA-A4 variant) with the susceptibility to the MB form suggests this variant for the transmembrane domain of the MICA molecule may be a risk factor for leprosy. Two MICA and nine HLA-B variants were found associated with leprosy per se in the Colônia do Prata population. Linkage disequilibrium analysis revealed perfect linkage disequilibrium (LD) between HLA-B markers rs2596498 and rs2507992, and high LD (R 2  = .92) between these and the marker rs2442718. This familial study demonstrates that MICA association signals are not independent from those observed for HLA-B. Our findings contribute the knowledge pool of the immunogenetics of Hansen's disease and reveals a new association of the MICA*029 allele., (© 2020 John Wiley & Sons Ltd.)

Despite intense efforts, the number of new cases of leprosy has remained significantly high over the past 20 years. Host genetic background is strongly linked to the pathogenesis of this disease, which is caused by Mycobacterium leprae (M. leprae), and there is a consensus that the most significant genetic association with leprosy is attributed to the major histocompatibility complex (MHC). Here, we investigated the association of human leukocyte antigen (HLA) class I and II genes with leprosy in a Brazilian population encompassing 826 individuals from a hyperendemic area of Brazil; HLA typing of class I (-A, -B, -C) and class II (-DRB1, -DQA1, -DQB1, -DPA1, and -DPB1) loci was conducted. Initially, the associations were tested using the chi-square test, with p-values adjusted using the false discovery rate (FDR) method. Next, statistically significant signals of the associations were submitted to logistic regression analyses to adjust for sex and molecular ancestry data. The results showed that HLA-C*08, -DPB1*04, and -DPB1*18 were associated with protective effects, while HLA-C*12 and -DPB1*105 were associated with susceptibility to leprosy. Thus, our findings reveal new associations between leprosy and the HLA-DPB1 locus and confirm previous associations between the HLA-C locus and leprosy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

Leprosy is an infectious disease caused by Mycobacterium leprae (M. leprae), with about 210,000 new cases per year worldwide. Although numerous risk loci have been uncovered by genome-wide association studies, the effects of common genetic variants are relatively modest. To identify possible new genetic locus involved in susceptibility to leprosy, whole exome sequencing was performed for 28 subjects including 14 patients and 12 unaffected members from 8 leprosy-affected families as well as another case and an unrelated control, and then the follow-up SNP genotyping of the candidate variants was studied in case-control sample sets. A rare missense variant in mitochondrial ribosomal protein S5 (MRPS5), rs200730619 (c. 95108402T>C [p. Tyr137Cys]) was identified and validated in 369 cases and 270 controls of Chinese descent (Padjusted = 0.006, odds ratio [OR] = 2.74) as a contributing factor to leprosy risk. Moreover, the mRNA level of MRPS5 was downregulated in M. leprae sonicate-stimulated peripheral blood mononuclear cells. Our results indicated that MRPS5 may be involved in leprosy pathogenesis. Further studies are needed to determine if defective MRPS5 could lead to impairment of energy metabolism of host immune cells, which could further cause defect in clearing M. leprae and increase susceptibility to infection., Competing Interests: The authors have declared that no competing interests exist.