title: LMP2/LMP7 gene variant: a risk factor for intestinal Mycobacterium tuberculosis infection in the Chinese population.
abstract: OBJECTIVE
  Low molecular mass protein-2 (LMP2) and low molecular mass protein-7 (LMP7) genes play a critical role in foreign antigen processing on the major histocompatibility complex-I CD8(+) cytotoxic T-lymphocyte pathway. This study was designed to investigate whether the sequence variants in the LMP2/LMP7 coding region were associated with intestinal Mycobacterium tuberculosis (M. tuberculosis) infection or with the co-infection of pulmonary tuberculosis.
  
  
  METHODS
  A total of 168 patients with intestinal tuberculosis and 235 normal controls were recruited for this study. Two polymorphisms of LMP2 (Arg60-His) and LMP7 (Gln145-Lys) were identified by polymerase chain reaction-restriction fragment length polymorphism method. The associations of the LMP2/LMP7 genotype and haplotype with intestinal M. tuberculosis infection were assessed by using logistic regression analysis.
  
  
  RESULTS
  The results revealed that LMP7 position codon 145 Lys/Lys and Gln/Lys alleles in the coding region were associated with the infection of intestinal M. tuberculosis (P=0.003, odds ratio [OR]= 3.86 and P < 0.001, OR = 2.28, respectively). Meanwhile, the Arg-Lys and Cys-Lys haplotypes exhibited significant relation to the intestinal M. tuberculosis infection (P= 0.006, OR=1.87; P=0.021, OR=1.83, respectively). No significant associations were observed for any of the single-nucleotide polymorphism genotypes or haplotypes with the co-infection of pulmonary tuberculosis (P > 0.05).
  
  
  CONCLUSIONS
  The results indicated that the genetic variant within the LMP2/LMP7 gene would increase the risk of intestinal M. tuberculosis infection.
authors.affiliation: Department of Anti-Infection and Institute of Clinical Pharmacology, Peking University First Hospital, Beijing, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lv
authors.forename: Bo
authors.initials: B
authors.lastname: Yan
authors.forename: Hongli
authors.initials: H
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhong
authors.forename: Kun
authors.initials: K
authors.lastname: Li
authors.forename: Ziping
authors.initials: Z
authors.lastname: Chen
authors.forename: Changqing
authors.initials: C
authors.lastname: Xu
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000378:metabolism; D004247:DNA / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D015994:Incidence; D008285:Major Histocompatibility Complex; D008297:Male; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D046988:Proteasome Endopeptidase Complex / Q000235:genetics* / Q000378:metabolism; D012189:Retrospective Studies; D012307:Risk Factors; D014385:Tuberculosis, Gastrointestinal / Q000453:epidemiology / Q000235:genetics* / Q000382:microbiology
chemical_list: C071313:LMP-2 protein; D004247:DNA; D003546:Cysteine Endopeptidases; C077436:LMP7 protein; D046988:Proteasome Endopeptidase Complex