TY - JOUR AU - Masood, Kiran Iqbal AU - Hussain, Rabia AU - Rao, Nisar AU - Rottenberg, Martin E AU - Salahuddin, Naseem AU - Irfan, Muhammad AU - Hasan, Zahra PY - 2014/01/15 Y2 - 2024/03/29 TI - Differential Early Secreted Antigen Target (ESAT) 6 kDa–induced IFN-γ and SOCS1 expression distinguishes latent and active tuberculosis JF - The Journal of Infection in Developing Countries JA - J Infect Dev Ctries VL - 8 IS - 01 SE - Original Articles DO - 10.3855/jidc.3412 UR - https://jidc.org/index.php/journal/article/view/24423713 SP - 059-066 AB - <p class="SmallText">Introduction: Expression of Suppressor of cytokine signaling (SOCS)-1 molecules is increased in patients with tuberculosis (TB). Early Secreted Antigen Target (ESAT)-6 kDa – induced IFN-γ responses indicate <em>Mycobacterium tuberculosis </em>infection. The effect of ESAT6- stimulation on SOCS1 in the host is not known.</p> <p class="SmallText">Methodology: Healthy asymptomatic controls had a negative (n = 16) or a positive ( n = 13) tuberculin skin test (TST). ESAT6-induced IFN- γ responses classified these controls as positive (EC ESAT6 IFN-γ (+), n = 5) or negative (EC ESAT6 IFN-γ (-), n = 24) responders. Patients had pulmonary (n = 21) or extra-pulmonary (n = 30) tuberculosis. Peripheral blood cells were stimulated with ESAT6 and mRNA expression of IFN- γ and SOCS1 was determined.</p> <p class="SmallText">Results: ESAT6-induced IFN-γ expression was raised in EC ESAT6 IFN-γ (+) as compared with EC ESAT6 IFN-γ (-), p = 0.019. ESAT6-induced SOCS1 mRNA expression was increased in both pulmonary TB and extra-pulmonary TB patients as compared with both EC groups. ESAT6-induced IFN-γ/SOCS1 mRNA expression ratio was decreased in TB patients as compared with both EC groups.</p> <p class="SmallText">Conclusion: <em>M. tuberculosis</em> infection induces increased ESAT6-induced IFN- γ responses in both latent and active TB. Our data shows down-regulation of IFN- γ / SOCS1 expression to be induced only in active TB cases, distinguishing them from healthy individuals likely to have latent TB. A decreasing IFN- γ /SOCS1 ratio may leads to reduced Th1 immunity which contributes to inability of the host to control clinical disease.</p> ER -