title: Joint effect of MCP-1 genotype GG and MMP-1 genotype 2G/2G increases the likelihood of developing pulmonary tuberculosis in BCG-vaccinated individuals.
abstract: We previously reported that the -2518 MCP-1 genotype GG increases the likelihood of developing tuberculosis (TB) in non-BCG-vaccinated Mexicans and Koreans. Here, we tested the hypothesis that this genotype, alone or together with the -1607 MMP-1 functional polymorphism, increases the likelihood of developing TB in BCG-vaccinated individuals. We conducted population-based case-control studies of BCG-vaccinated individuals in Mexico and Peru that included 193 TB cases and 243 healthy tuberculin-positive controls from Mexico and 701 TB cases and 796 controls from Peru. We also performed immunohistochemistry (IHC) analysis of lymph nodes from carriers of relevant two-locus genotypes and in vitro studies to determine how these variants may operate to increase the risk of developing active disease. We report that a joint effect between the -2518 MCP-1 genotype GG and the -1607 MMP-1 genotype 2G/2G consistently increases the odds of developing TB 3.59-fold in Mexicans and 3.9-fold in Peruvians. IHC analysis of lymph nodes indicated that carriers of the two-locus genotype MCP-1 GG MMP-1 2G/2G express the highest levels of both MCP-1 and MMP-1. Carriers of these susceptibility genotypes might be at increased risk of developing TB because they produce high levels of MCP-1, which enhances the induction of MMP-1 production by M. tuberculosis-sonicate antigens to higher levels than in carriers of the other two-locus MCP-1 MMP-1 genotypes studied. This notion was supported by in vitro experiments and luciferase based promoter activity assay. MMP-1 may destabilize granuloma formation and promote tissue damage and disease progression early in the infection. Our findings may foster the development of new and personalized therapeutic approaches targeting MCP-1 and/or MMP-1.
authors.affiliation: The Methodist Hospital Research Institute, The Methodist Hospital, Houston, Texas, United States of America.
authors.forename: Malathesha
authors.initials: M
authors.lastname: Ganachari
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Ruiz-Morales
authors.forename: Juan C
authors.initials: JC
authors.lastname: Gomez de la Torre Pretell
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Dinh
authors.forename: Julio
authors.initials: J
authors.lastname: Granados
authors.forename: Pedro O
authors.initials: PO
authors.lastname: Flores-Villanueva
mesh_terms: D000293:Adolescent; D000328:Adult; D001500:BCG Vaccine / Q000008:administration & dosage*; D018932:Chemokine CCL2 / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D016013:Likelihood Functions; D008800:Mexico; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D014397:Tuberculosis, Pulmonary / Q000235:genetics*; D055815:Young Adult
chemical_list: D001500:BCG Vaccine; D018932:Chemokine CCL2