RESUMO
The innate immune system is critical for clearing infection, and is tightly regulated to avert excessive tissue damage. Nod1/2-Rip2 signaling, which is essential for initiating the innate immune response to bacterial infection and ER stress, is subject to many regulatory mechanisms. In this study, we found that LRRK2, encoded by a gene implicated in Crohn's disease, leprosy and familial Parkinson's disease, modulates the strength of Nod1/2-Rip2 signaling by enhancing Rip2 phosphorylation. LRRK2 deficiency markedly reduces cytokine production in macrophages upon Nod2 activation by muramyl dipeptide (MDP), Nod1 activation by D-gamma-Glu-meso-diaminopimelic acid (iE-DAP) or ER stress. Our biochemical study shows that the presence of LRRK2 is necessary for optimal phosphorylation of Rip2 upon Nod2 activation. Therefore, this study reveals that LRRK2 is a new positive regulator of Rip2 and promotes inflammatory cytokine induction through the Nod1/2-Rip2 pathway.
Assuntos
Citocinas/imunologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/imunologia , Proteína Adaptadora de Sinalização NOD1/imunologia , Proteína Adaptadora de Sinalização NOD2/imunologia , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/imunologia , Proteína Serina-Treonina Quinases de Interação com Receptores/imunologia , Transdução de Sinais/imunologia , Animais , Citocinas/genética , Células HEK293 , Humanos , Imunidade Inata/genética , Inflamação/genética , Inflamação/imunologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Camundongos , Camundongos Knockout , Proteína Adaptadora de Sinalização NOD1/genética , Proteína Adaptadora de Sinalização NOD2/genética , Fosforilação/genética , Fosforilação/imunologia , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Transdução de Sinais/genéticaRESUMO
In recent years, genome wide association studies have discovered a large number of gene loci that play a functional role in innate and adaptive immune pathways associated with leprosy susceptibility. The immunological control of intracellular bacteria M. leprae is modulated by NOD2-mediated signaling of Th1 responses. In this study, we investigated 211 clinically classified leprosy patients and 230 ethnically matched controls in Indian population by genotyping four variants in NOD2 (rs9302752A/G), LRRK2 (rs1873613A/G), RIPK2 (rs40457A/G and rs42490G/A). The LRRK2 locus is associated with leprosy outcome. The LRRK2 rs1873613A minor allele and respective rs1873613AA genotypes were significantly associated with an increased risk whereas the LRRK2 rs1873613G major allele and rs1873613GG genotypes confer protection in paucibacillary and leprosy patients. The reconstructed GA haplotypes from RIPK2 rs40457A/G and rs42490G/A variants was observed to contribute towards increased risk whereas haplotypes AA was observed to confer protective role. Our results indicate that a possible shared mechanisms underlying the development of these two clinical forms of the disease as hypothesized. Our findings confirm and validates the role of gene variants involved in NOD2-mediated signalling pathways that play a role in immunological control of intracellular bacteria M. leprae.
Assuntos
Predisposição Genética para Doença , Hanseníase/genética , Mycobacterium leprae , Proteína Adaptadora de Sinalização NOD2/genética , Proteínas Serina-Treonina Quinases/genética , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genética , Transdução de Sinais/genética , Alelos , Feminino , Haplótipos/genética , Haplótipos/imunologia , Humanos , Índia/epidemiologia , Hanseníase/epidemiologia , Hanseníase/imunologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Masculino , Proteína Adaptadora de Sinalização NOD2/imunologia , Polimorfismo Genético/genética , Polimorfismo Genético/imunologia , Proteínas Serina-Treonina Quinases/imunologia , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/imunologia , Transdução de Sinais/imunologia , Células Th1/imunologiaRESUMO
We performed a genome-wide association study with 706 individuals with leprosy and 5,581 control individuals and replicated the top 24 SNPs in three independent replication samples, including a total of 3,301 individuals with leprosy and 5,299 control individuals from China. Two loci not previously associated with the disease were identified with genome-wide significance: rs2275606 (combined P = 3.94 × 10(-14), OR = 1.30) on 6q24.3 and rs3762318 (combined P = 3.27 × 10(-11), OR = 0.69) on 1p31.3. These associations implicate IL23R and RAB32 as new susceptibility genes for leprosy. Furthermore, we identified evidence of interaction between the NOD2 and RIPK2 loci, which is consistent with the biological association of the proteins encoded by these genes (NOD2-RIPK2 complex) in activating the NF-κB pathway as a part of the host defense response to infection. Our findings have expanded the biological functions of IL23R by uncovering its involvement in infectious disease susceptibility and suggest a potential involvement of autophagocytosis in leprosy pathogenesis. The IL23R association supports previous observations of the marked overlap of susceptibility genes for leprosy and Crohn's disease, implying common pathogenesis mechanisms.
Assuntos
Predisposição Genética para Doença , Hanseníase/genética , Polimorfismo de Nucleotídeo Único , Receptores de Interleucina/genética , Proteínas rab de Ligação ao GTP/genética , Idoso , Estudos de Casos e Controles , Cromossomos Humanos Par 11 , Epistasia Genética , Feminino , Estudo de Associação Genômica Ampla , Haplótipos , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Proteína Adaptadora de Sinalização NOD2/genética , Análise de Componente Principal , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genéticaRESUMO
Leprosy is caused by Mycobacterium leprae, and the global registered prevalence of leprosy at the beginning of 2009 stood at 213,036 cases. It has long been thought that leprosy has a strong genetic risk. Recently, we have identified significant associations (P < 1.00 × 10(-10)) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR and RIPK2 and a trend towards an association (P = 5.10 × 10(-5)) with a SNP in LRRK2. Here, we investigated the expression of these seven genes in formalin-fixed, paraffin-embedded skin tissues of leprosy and matched normal tissues using branched DNA technology. This technology allows for direct measurement of targeted mRNA within cellular lysate using a 96-well plate format in a time frame compared to a reporter gene assay. The clear upregulation of all seven genes was found in leprosy tissues compared to normal tissues, which further supports our genome-wide association study results.