Apoptosis of γδT cells and αβT cells induced by ceramide

Objective: To investigate the role of apoptosis of γδT cells and αβT cells induced by ceramide.Methods: The peripheral blood mononuclear lymphocytes of healthy donors were stimulated respectively with the low molecular peptide antigen derived from Mycobacterium tuberculosis antigen(Mtb Ag) and CD3mAb to generate Mtb Ag activated T cells(γδT cells were predominent) and CD3mAb activated T cells(αβT cells were predominent).These two T cell subsets were treated with Ceramide(C2 Cer) at different concentration;after 3hours of cultivation,the apoptosis of different subsets of T cells was measured by flowcytometry(FCM),using Annexin V FITC/PI staining;and the availability of T cells was detected by methl thiazolyl tetrazolium(MTT) colorimetric assay.Results: The percentage of γδT cells in Mtb Ag activated T cells and αβT cells in CD3mAb activated T cells were 70% to 90% and >90%,respectively.The apoptosis and the inhibition of the availability of γδT cells and αβT cells induced by lower concentration of C2 Cer(≤ 10 μmol/L)appeared weak in contrast to their control.There were significant differences in the role of apoptosis of γδT cells and αβT cells induced by higher concentration of C2 Cer;the percentage of the apoptotic γδT cells and αβT cells induced by C2 Cer(100 μmol/L) increased by 10.4%(P>0.05) and 73.5%(P<0.01) in contrast with their control,and the percentage of cells in the region live cells(R1) was 88.1%(P>0.05) and 7.8%(P<0.01) of the ones of their control;whereas the percentage of the apoptotic γδT cells and αβT cells induced by C2 Cer(500 μmol/L) increased by 71.9% and 73.8%(P<0.01) in contrast with their control,and the percentage of cells in R1 was 36.5% and 2.7%(P<0.01) of the ones of their control.Conclusions: The apoptosis of γδT cells and αβT cells can be induced by ceramide;it needs higher concentration of C2 Cer to induce the apoptosis of γδT cells than to induce the apoptosis of αβT cells.