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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-ß1 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.

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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.

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Leprosy is a disease with a clinical spectrum of presentations that is also manifested in diverse histological features. At one pole, lepromatous lesions (L-pole) have phagocytic foamy macrophages heavily parasitized with freely multiplying intracellular Mycobacterium leprae. At the other pole, the presence of epithelioid giant cells and granulomatous formation in tuberculoid lesions (T-pole) lead to the control of M. leprae replication and the containment of its spread. The mechanism that triggers this polarization is unknown, but macrophages are central in this process. Over the past few years, leprosy has been studied using large scale techniques to shed light on the basic pathways that, upon infection, rewire the host cellular metabolism and gene expression. M. leprae is particularly peculiar as it invades Schwann cells in the nerves, reprogramming their gene expression leading to a stem-like cell phenotype. This modulatory behavior exerted by M. leprae is also observed in skin macrophages. Here, we used live M. leprae to infect (10:1 multiplicity of infection) monocyte-derived macrophages (MDMs) for 48 h and analyzed the whole gene expression profile using microarrays. In this model, we observe an intense upregulation of genes consistent with a cellular immune response, with enriched pathways including peptide and protein secretion, leukocyte activation, inflammation, and cellular divalent inorganic cation homeostasis. Among the most differentially expressed genes (DEGs) are CCL5/RANTES and CYP27B1, and several members of the metallothionein and metalloproteinase families. This is consistent with a proinflammatory state that would resemble macrophage rewiring toward granulomatous formation observed at the T-pole. Furthermore, a comparison with a dataset retrieved from the Gene Expression Omnibus of M. leprae-infected Schwann cells (MOI 100:1) showed that the patterns among the DEGs are highly distinct, as the Schwann cells under these conditions had a scavenging and phagocytic gene profile similar to M2-like macrophages, with enriched pathways rearrangements in the cytoskeleton, lipid and cholesterol metabolism and upregulated genes including MVK, MSMO1, and LACC1/FAMIN. In summary, macrophages may have a central role in defining the paradigmatic cellular (T-pole) vs. humoral (L-pole) responses and it is likely that the multiplicity of infection and genetic polymorphisms in key genes are gearing this polarization.

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BACKGROUND Leprosy is a chronic infectious disease caused by Mycobacterium leprae, and compromises the skin and peripheral nerves. This disease has been classified as multibacillary (MB) or paucibacillary (PB) depending on the host immune response. Genetic epidemiology studies in leprosy have shown the influence of human genetic components on the disease outcomes. OBJECTIVES We conducted an association study for IL2RA and TGFB1 genes with clinical forms of leprosy based on two case-control samples. These genes encode important molecules for the immunosuppressive activity of Treg cells and present differential expressions according to the clinical forms of leprosy. Furthermore, IL2RA is a positional candidate gene because it is located near the 10p13 chromosome region, presenting a linkage peak for PB leprosy. METHODS A total of 885 leprosy cases were included in the study; 406 cases from Rondonópolis County (start population), a hyperendemic region for leprosy in Brazil, and 479 cases from São Paulo state (replication population), which has lower epidemiological indexes for the disease. We tested 11 polymorphisms in the IL2RA gene and the missense variant rs1800470 in the TGFB1 gene. FINDINGS The AA genotype of rs2386841 in IL2RA was associated with the PB form in the start population. The AA genotype of rs1800470 in TGFB1 was associated with the MB form in the start population, and this association was confirmed for the replication population. MAIN CONCLUSIONS We demonstrated, for the first time, an association data with the PB form for a gene located on chromosome 10. In addition, we reported the association of TGFB1 gene with the MB form. Our results place these genes as candidates for validation and replication studies in leprosy polarisation.

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BACKGROUND Leprosy is a chronic infectious disease caused by Mycobacterium leprae, and compromises the skin and peripheral nerves. This disease has been classified as multibacillary (MB) or paucibacillary (PB) depending on the host immune response. Genetic epidemiology studies in leprosy have shown the influence of human genetic components on the disease outcomes. OBJECTIVES We conducted an association study for IL2RA and TGFB1 genes with clinical forms of leprosy based on two case-control samples. These genes encode important molecules for the immunosuppressive activity of Treg cells and present differential expressions according to the clinical forms of leprosy. Furthermore, IL2RA is a positional candidate gene because it is located near the 10p13 chromosome region, presenting a linkage peak for PB leprosy. METHODS A total of 885 leprosy cases were included in the study; 406 cases from Rondonópolis County (start population), a hyperendemic region for leprosy in Brazil, and 479 cases from São Paulo state (replication population), which has lower epidemiological indexes for the disease. We tested 11 polymorphisms in the IL2RA gene and the missense variant rs1800470 in the TGFB1 gene. FINDINGS The AA genotype of rs2386841 in IL2RA was associated with the PB form in the start population. The AA genotype of rs1800470 in TGFB1 was associated with the MB form in the start population, and this association was confirmed for the replication population. MAIN CONCLUSIONS We demonstrated, for the first time, an association data with the PB form for a gene located on chromosome 10. In addition, we reported the association of TGFB1 gene with the MB form. Our results place these genes as candidates for validation and replication studies in leprosy polarisation.

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A hanseníase é uma patologia causada pelo Mycobacterium leprae, bacilo que infecta macrófagos e células de Schwann, gerando lesões cutâneas e comprometendo nervos periféricos. Ocupa importante papel nas ações do Ministério da Saúde, uma vez que o Brasil está em segundo lugar no ranking mundial em número de casos da doença. Estudos prévios indicaram associação da região cromossômica 10p13 com a hanseníase paucibacilar. O gene GATA3, localizado na região 10p15, é assim um candidato posicional e funcional para a associação com a hanseníase, já que induz a resposta Th2 que é permissiva para a replicação do M. leprae. O polimorfismo genético rs10905284 no gene GATA3, já associado à hanseníase per se na população brasileira, está localizado em um intron próximo à região 3’UTR e a apenas 1220pb do polimorfismo rs1058240, que está em um sítio de ligação de microRNA. Assim, o objetivo do presente trabalho foi investigar a associação do SNP rs1058240 no gene GATA3 com a hanseníase per se aplicando um estudo de associação baseado em população. Para tanto, 1.785 indivíduos de duas amostras caso-controle foram incluídas no desenho do estudo: 835 indivíduos de Rondonópolis-MT e 950 do Estado de São Paulo. A análise de regressão logística univariada, com e sem ajuste para as co-variáveis sexo e etnia, demonstrou que o alelo rs1058240 não está associado à hanseníase per se ou suas formas clínicas na população de Rondonópolis. Respeitando o desenho proposto inicialmente, a investigação da população do estado de São Paulo não foi realizada. A análise de desequilíbrio de ligação (LD) demonstrou que o polimorfismo rs1058240 não está em LD com o previamente associado à hanseníase (rs10905284). Assim, concluímos que o polimorfismo rs1058240 no gene GATA3 não está associado à hanseníase, e que o efeito observado para o rs10905284 é independente do polimorfismo avaliado neste estudo...

Leprosy is a disease caused by Mycobacterium leprae that infects macrophages and Schwann cells that leads to cutaneous injuries and compromises peripheral nerves. It plays an important role in the Brazilian Health Ministry actions, since Brazil ranks second in the worldwide rank in numbers of cases. Ligation studies have indicated an association of chromosomal region 10p13 to clinical forms of leprosy. The GATA3 gene at chromosomal region 10p15 is a functional and positional candidate gene for leprosy susceptibility. It induces Th2 immune response, which favors M. leprae replication. The rs10905284 genetic polymorphism, located in an intron of GATA3 and close to the 3’UTR region was associated to leprosy per se. It is 1,220bp from another polymorphism, rs1058240, which is in a microRNA binding site. Thus, our aim was to investigate if the rs1058240 polymorphism is associated to leprosy per se through a population-based association study. Therefore, 1,785 individuals from two case-control samples were included in the design: 835 individuals from Rondonópolis-MT and 950 from São Paulo state. The logistic regression models analysis did not point association between rs1058240 polymorphism and leprosy. The linkage disequilibrium (LD) analysis demonstrated that these markers are not in LD. We conclude that rs1058240 polymorphism is not associated to leprosy and that the effect of rs10905284 is independent...

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