Specific stimulation of B cell epitope peptides from Mycobacterium tuberculosis antigen on human peripheral γδT cells / 中国免疫学杂志

ABSTRACT

Objective:To investigate the specific stimulation of the B cell epitope peptides of Mycobacterium tuberculosis antigen (Mtb-Ag) on human peripheral γδ T cell proliferation.Methods: We selected the sequences of B cell epitope peptide from Mtb-Ag that were reported in literature and T cell epitope peptide that recently identified in this laboratory to synthesize six peptides of B cell epitopes (BP1-BP6) and two peptides of γδ T cell epitopes (TP14,TP15).The 24-well culture plates were coated with these peptides.The PBMCs were isolated from peripheral blood of healthy individuals and stained with CFSE,followed cultured for 12 days in the IL-2 containing medium.Mtb heat resistant antigen ( Mtb-HAg ) group as positive control and IL-2 only group as negative control.The percentages and proliferation index of γδ T cells were determined by flow cytometry.Results: By using Wilcoxon signed rank test for paired comparison of negative control group,the percentages of γδ T cells in cultured PBMCs with BP2,BP4 and TP14, TP15 and Mtb-HAg increased significantly in 14 samples (P<0.05);and the proliferation index of γδT cell in cultured PBMCs with BP2,BP4,BP5,BP6 and TP14,TP15 increased significantly in 7 samples (P<0.05).Conclusion: Taken together,the B cell epitope peptides from Mtb Antigens are capable of stimulating the γδ T cell proliferation specifically in vitro.Although there was individual difference inγδT cell proliferative response to B cell epitope peptides,these results strongly suggest the B cell epitope peptides also can specifically trigger the TCR ofγδT cells.