ABSTRACT
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb), and remains a leading public health problem. Previous studies have identified host genetic factors that contribute to Mtb infection outcomes. However, much of the heritability in TB remains unaccounted for and additional susceptibility loci most likely exist. We perform a multistage genome-wide association study on 2949 pulmonary TB patients and 5090 healthy controls (833 cases and 1220 controls were genome-wide genotyped) from Han Chinese population. We discover two risk loci: 14q24.3 (rs12437118, Pcombined = 1.72 × 10-11, OR = 1.277, ESRRB) and 20p13 (rs6114027, Pcombined = 2.37 × 10-11, OR = 1.339, TGM6). Moreover, we determine that the rs6114027 risk allele is related to decreased TGM6 transcripts in PBMCs from pulmonary TB patients and severer pulmonary TB disease. Furthermore, we find that tgm6-deficient mice are more susceptible to Mtb infection. Our results provide new insights into the genetic etiology of TB.
Subject(s)
Receptors, Estrogen/genetics , Transglutaminases/genetics , Tuberculosis/genetics , Animals , Asian People , Case-Control Studies , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , HEK293 Cells , Humans , Male , Mice, Inbred C57BL , Mice, Knockout , Transglutaminases/metabolismABSTRACT
Tuberculosis (TB) remains a major global health problem and host genetic factors play a critical role in susceptibility and resistance to TB. The aim of this study was to identify novel candidate genes associated with TB susceptibility. We performed a population-based case-control study to genotype 13 tag SNPs spanning Epstein-Barr virus-induced gene 3 (EBI3), colony stimulating factor 2 (CSF2), IL-4, interferon beta 1 (IFNB1), chemokine (C-X-C motif) ligand 14 (CXCL14) and myeloid differentiation primary response gene 88 (Myd88) genes in 435 pulmonary TB patients and 375 health donors from China. We observed that EBI3 gene rs4740 polymorphism was associated with susceptibility to pulmonary tuberculosis (PTB) and the allele G was associated with a protective effect against PTB. Furthermore, EBI3 deficiency led to reduced bacterial burden and histopathological impairment in the lung of mice infected with Mycobacterium bovis BCG. Meanwhile, higher abundance of EBI3 was observed in the granuloma of PTB patients and in the lung tissue of BCG-infected mice. Of note, the expression of EBI3 in macrophages was remarkably induced by mycobacteria infection at both mRNA and protein level. In conclusion, EBI3 gene rs4740 polymorphism is closely associated with susceptibility to PTB and the elevation and enrichment of EBI3 in the lung which at least partially derived from macrophages may contribute to the exacerbation of mycobacterial infection.
