Effects of mycobacterium tuberculosis antigen on proliferation of human γδT cellsin vitro

Objective To observe the effects of mycobacterium tuberculosis antigen on the proliferation of human γδT cells in vitro and resolve the problem of γδT cells shortage.Methods Acid L-G medium was used to isolate mycobacterium tuberculosis(Mtb)and sodium pyruvate medium was employed to proliferate the bacteria.Soluble extracts Mtb-Ag was obtained by heat-treating at 85℃ and sequentially disrupted by prolonged sonication.Mtb-Ag was used to stimulate peripheral blood mononuclear cells at different doses in vitro.The proliferation of PBMC was detected by MTT chromatometry method during culture.The percentage of γδT cells was measured by flow cytometry.Results The capability of Mtb antigens to stimulate PBMC proliferation varied with the dose.PBMC proliferation was dose-dependent from Mtb antigens in given range.It was demonstrated by flow cytometry that 7μg/ml dose Mtb-Ag group could stimulate γδT cells remarkably to the highest level(approximately 49.08%).But when the stimulation dose increased to 9μg/ml,the percentage of γδT cells started to decrease(approximately 32.62%)while T cell ratio increased markedly(approximately 36.76%).Conclusion In vitro,the component of Mtb-Ag can effectively stimulate the proliferation of human γδT cells.The results indicates that MtbAg can dominantly induceγδT cells proliferation at proper dose and activateαβT cells only athigher dose.