title: γδ T cells response to Mycobacterium tuberculosis in pulmonary tuberculosis patients using preponderant complementary determinant region 3 sequence.
abstract: OBJECTIVE
  The unique immunological functions of γδ T lymphocytes to contribute immunity against Mycobacterium tuberculosis attracted interest of researchers. However, little is known about the specificity of γδ Τ cell in tuberculosis patients and the lack of exact tuberculosis antigen recognized by γδ T cells limited its application. The analysis of complementary determinant region (CDR)3 sequence characteristic in γδ T cells of tuberculosis patients would contribute to understand the distribution specificity of γδ T cell. In present study, we investigated the diversity of the γ9/δ2 T cell immunorepertoire and analysed the specificity of the expressed CDR3 in pulmonary tuberculosis patients.
  
  
  METHODS
  The total RNA in peripheral blood mononuclear cell of 50 pulmonary tuberculosis patients and 10 healthy controls was extracted. The polymerase chain reaction was used to specifically amplify the CDR3 region of γ9 and δ2 chain. The PCR products were ligated into the pGEM-T easy vector. The plasmid DNA was sequenced using the ABI3700 and the T7 primer.
  
  
  RESULTS
  Our findings showed that predominant CDR3 sequence of δ2 chain in pulmonary tuberculosis patients was CACDTLVSTDKLIFGKG. The sequence specifically exists in almost all pulmonary tuberculosis patients. The conserved hydrophobic acid residue in 97 positions is present in the γδ T cell reactive to M. tuberculosis. The length of δ2 CDR3 in pulmonary tuberculosis patients has no relation with the disease progress.
  
  
  CONCLUSIONS
  Our results suggest that γδ T cells appear to use CDR3 sequence to recognise M. tuberculosis antigen. γδ T cells reactive to M. tuberculosis were diverse and polyclonal.
authors: State Key Laboratory for Molecular Virology and Genetic Engineering, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, PR, China.
authors: Xueyan
authors: X
authors: Xi
authors: Xiqin
authors: X
authors: Han
authors: Liang
authors: L
authors: Li
authors: Zhendong
authors: Z
authors: Zhao
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D022801:Complementarity Determining Regions / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D016133:Polymerase Chain Reaction; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014397:Tuberculosis, Pulmonary / Q000276:immunology*
chemical_list: D022801:Complementarity Determining Regions; D017931:DNA Primers; D016692:Receptors, Antigen, T-Cell, gamma-delta