Expression and significance of IFN-γ and IL-17 in γδ T cells of tuberculosis patients

Objective To investigate the effects of Mtb-HAg on the production of IFN-γ and IL-17 in γδ T cells from peripheral blood of peripheral blood mononuclear cell (PBMCs) from normal people (HC) and tuberculosis patients (TB). Methods PBMCs were isolated from the peripheral blood of 12 HC and 12 TB patients and cultured for 12 days. The cells in the experimental group were stimulated by using Mtb-HAg for 2 h and then further cultured for 4 h in Monensin; while the cells in the negative control group without receiving the stimulation with Mtb-HAg. The cells were harvested and labeled with fluorescent-labeled McAb for surface and intracellular staining. The γδ T cells in both groups were assayed by flow cytometry for the production of IFN-γ and IL-17 cells relative proportions. Results The γδ T cells in both experimental group and negative control group were able to produce IFN-γ. IFN-γ produced by γδ T cells stimulated by Mtb-HAg was significantly higher than that by cells without receiving stimulation with Mtb-HAg (P<0.001), and there was significant difference between TB group and HC group (P<0.001). In HC group,the rate of γδ T cells producing IL-17 decreased in both experimental group and negative control group without statistical significance difference, however, in TB group, the same trend showed significant difference between the experimental group and negative control group. Conclusion The γδ T cells from PBMCs in TB patients are sensitive to the stimulation with Mtb-Hag,but its ability to produce IL-17 decreases obviously.