The dynamics of L-selectin expression on activated human γδT cells by Mycobacterium tuberculosis antigen during in vitro proliferation

Objective: To study dynamic expression of L-selctin(CD62L) in human peripheral γδT cells activated with Mycobacterium tuberculosis antigen(MtbAg) and cultured for proliferation.Methods: Peripheral blood mononuclear cells(PBMC) were stimulated with MtbAg to generate MtgAg activated T cells(MtbAT),or with CD3mAb activated αβT cells(CD3AT).Fresh isolation PBMC and cultured MtbAT or CD3AT for 3 to 21 days were stained with multicolor fluorescence mAbs.The percentage of CD62L⁺ cells among fresh PBMC,MtbAT or CD3AT were measured by flow cytometry.Results: The percentage of CD62L⁺ cells of γδT cells(43.9%) in fresh PBMC has significant lower than that of αβT cells(76.6%),the expression of CD62L arrived at climax on day 6 of culture in γδT cells(90.7%) and αβT cells(87.2%),after then the expression of CD72L decreased and maintained low level,the percentages of CD62L⁺ cells of γδU cells and αβT cells were 16.2% to 10.6% aod 23.6% to 17.5%,respectively,from day 15 to day 21 of culture.Conclusions: The CD62L expression of γδT cells in fresh PBMC was lower than that of αβTcells,but after activated by stimulation of MtbAg or CD3Ab,the expression of CD62L in human peripheral γδT cells,like αβTcells,rose in first and then decreased,and maintained low level later.