BACKGROUND Leprosy or hansen’s disease is a spectral disease whose clinical forms mostly depends on host’s immune and genetic factors. Different Toll-like receptors (TLR) variants have been described associated with leprosy, but with some lack of replication across different populations.OBJECTIVES To evaluate the role of polymorphisms in genes TLR1, TLR2 and TLR4 and susceptibility to leprosy in a genetic case control study; to verify the association between genotypes of these markers and the immunological profile in the serum of patients with leprosy.METHODS Pre-designed TaqMan® assays were used to genotype markers at TLR1 (rs4833095, rs5743551), TLR2 (rs7656411, rs3804099) and TLR4 (rs1927914, rs1927911). A panel of cytokines and chemokines was accessed by enzime-linked immunosorbent assay (ELISA) test in the serum of a subgroup of patients with and without leprosy reactions.FINDINGS Our results show an association between the T allele of rs3804099 at the TLR2 gene and increased risk for leprosy per se [Odds ratio (OR) = 1.296, p = 0,022]. In addition, evaluating the association between different genotypes of the TLR1, 2 and 4 markers and cytokine/chemokine serological levels, IL-17 appears as an immunological marker regulated by the polymorphism of the three TLR genes evaluated, whereas different TLR1 genotypes were associated with differential production of IL-12p40 and MCP-1(CCL2). Furthermore, other relevant serum markers such as CXCL-10 and IL-6 seemed to be regulated by TLR2 variants and IL-1β was related to TLR4 genotypes.MAIN CONCLUSIONS All together our data points that the tested TLR markers may have a regulatory role in the immunity against Mycobacterium leprae, by driving the host’s production of key cytokines and chemokines involved in the pathogenesis of this disease.

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BackgroundThe major factors contributing for nerve damage and permanent disabilities in leprosy are type 1 or reversal reactions (RR) and type 2 or erythema nodosum leprosum (ENL). Gene profiling of leprosy reactions have shown that different pathways are activated during the course of reactions, which is consistent with the exacerbated immune response exhibited by these patients.MethodsWe used qPCR to screen a panel of 90 genes related to the immune response in leprosy in RNA-derived peripheral leukocytes of patients with (N = 94) and without leprosy reactions (N = 57) in order to define expression signatures correlated to RR or ENL.ResultsOur results show that there is a marked signature for RR in the blood, comprising genes mostly related to the innate immune responses, including type I IFN components, autophagy, parkins and Toll like receptors. On the other hand, only Parkin was differentially expressed in the ENL group.ConclusionsThe data put together corroborates previous work that brings evidence that an acute uncontrolled exacerbated immune response designed to contain the spread of M. leprae antigens might be cause of RR pathogenesis. Identifying a blood profile useful to predict leprosy reactions prior to its development might help to reduce the morbidity associated to this disabling disease.

Mycobacterium leprae infects skin and peripheral nerves causing deformities and disability. The M. leprae bacterium binds to ErbB2 on the Schwann cell surface causing demyelination and favoring spread of the bacilli and causing nerve injury. Polymorphisms at the ERBB2 gene were previously investigated as genetic risk factors for leprosy in two Brazilian populations but with inconsistent results. Herein we extend the analysis of ERBB2 variants to a third geographically distinct population in Brazil. Our results show that there is no association between the genotyped SNPs and the disease (p>0.05) in this population. A gene set or pathway analysis under the genomic region of ERBB2 will be necessary to clarify its regulation under M. leprae stimulus.

Background. Mycobacterium leprae infects skin and peripheral nerves causing a broad of clinical forms. Data have shown that the miR-125a-3p can influence immune mechanisms such as autophagy as well as to target genes leading to abnormal proliferation, metastasis, and invasion of cells. Methods. Here we used quantitative real time PCR (qPCR) to evaluate the miR-125a-3p expression pattern as a marker for leprosy phenotypes in biopsies obtained from patients with and without reactions. Data were analysed according to clinical forms and bacillary index (BI). Results. Our results show a significant increase in the miR-125a-3p expression in paucibacillary (PB) vs multibacillary (MB) (p = 0.007) and vs RR (reversal reactions) (p = 0.005), respectively; and also a higher expression in patients with erythema nodosum leprosum (ENL) vs MB without reactions (p = 0.002). In addition, there was a positive correlation between the miR-125a-3p expression and BI in patients with reactions (r=0,81; p=0,002). Conclusions. All together we underpin a role for miR-125-3p in leprosy pathogenesis, raising the hypothesis that this miR might have a distinct role in PB and ENL forms, influencing mechanisms such as apoptosis and autophagy according to the local context. A functional study should help to validate the miR-125a-3p as a potential therapeutic target for leprosy treatment.