Interferon gamma gene +874A/T polymorphism and intracellular interferon gamma expression in pulmonary tuberculosis.
We investigated whether IFN-gamma gene +874(A/T) polymorphism influences intracellular interferon gamma expression in T-cell subsets of normal healthy subjects (NHS) and pulmonary tuberculosis patients (PTB). Peripheral blood mononuclear cells were stimulated with live Mycobacterium tuberculosis (MTB) and the intracellular IFN-gamma expression was studied using flow cytometry. Genotyping of IFN-gamma gene +874(A/T) was done using allele specific polymerase chain reaction. Significantly increased IFN-gamma expressing CD3+CD4+ and CD3+CD8+ T cells were observed in NHS with AA genotype compared to TT genotype in unstimulated (p=0.0308 and p=0.0157) and MTB stimulated (p=0.0494 and p=0.0287) cultures and this difference was not observed in PTB patients. The present study suggests that the variant genotypes of IFN-gamma (+874) may be associated with altered expression of IFN-gamma at the intracellular level and play an immunoregulatory role at the site of M. tuberculosis infection.
Prabhu Anand
S
S
Department of Immunology, Tuberculosis Research Centre, Indian Council of Medical Research, Mayor V.R. Ramanathan Road, Chennai 600 031, India.
Harishankar
M
M
Selvaraj
P
P
D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D005838:Genotype; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics* / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology; D011110:Polymorphism, Genetic; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000235:genetics / Q000276:immunology*
D015415:Biomarkers; D007371:Interferon-gamma