Investigation on resistance mechanisms of tuberculosis though the function changes of Th17 cell and CD4^+ CD25^+ Foxp3^+ regulatory T cells

Objective To analyze the changes of Th17 cells,CD4⁺CD25⁺Foxp3⁺regulatory T(Treg)cells,and cells cytokines in peripheral blood of tuberculosis patients with drug-resistant,and investigate the resistance mechanism though immunological point. Methods Thirty-there cases of drug-resistant tuberculosis patients(resistance group),49 cases of ordinary TB(general group),and 51 healthy volunteers(control group)were selected and comparative studied.The Th17 cells and CD4⁺CD25⁺Foxp3⁺ Treg cells ratio were detected.The expression of specific transcription factors RORγt and mRNA in Foxp3 were detected by RT-PCR.The serum IL-17A,IL-17F,TGF-β1 and IL-10 levels were detected by ELISA. Results The Th17 cells ratio and RORγt mRNA expression of normal group were lower than the control group,and resistance group were lower than the normal group;The CD4⁺CD25⁺Foxp3⁺ Treg cells ratio and Foxp3 mRNA expression were higher than the control group,and resistance group were higher than normal group;The Th17/CD4⁺CD25⁺Foxp3⁺ Treg cells and RORγt/Foxp3 of normal group were lower than the control group,and resistance group were lower than normal group(P<0.05).IL-17A and IL-17F levels of normal group were lower than control group,and resistance group were lower than normal group.The TGF-β1 and IL-10 levels were higher than control group,and resistance group were higher than normal group(P<0.05). Conclusion The balance offset of Th17/CD4⁺CD25⁺Foxp3⁺ Treg cell to CD4⁺CD25⁺Foxp3⁺ Treg cell and immune system suppression might be one of important mechanism of chronic and produce resistant in tuberculosis.