The Role Of CD59 In LAT-mediated Signal Transduction Of T Lymphocytes

Objective To investigate the effect of CD59 on T lymphocyte proliferation and the function of CD59 in LAT induced T lymphocytes' proliferation and down-stream signaling transduction.Methods Jurkat cells were transfected with pSUPER-siCD59 plasmids by electroporetion or stimulated by anti-CD59 antibody.Cells proliferation was measured by MTT assay.Western blot was performed for the detection of CD59 expression and ZAP70 phosphorylation.Meanwhile,LAT-GFP recombinant lentiviral vectors were transfected into Jurkat cells and stable-expression cell line were established named Junket-GFP.Junket-GFP cells were electroporeted with pSUPER-siCD59 plasmids and stimulated by CD59 antibody,too.The locations of CD59 and LAT molecules were observed under fluorescence microscope with the immunofluorescence cytochemistry.The cells proliferation activities were measured by MTT assay.we used western blot to detect the phosphorylation levels of several down-stream protein molecules after T cell activated.Results Compared with the untreated control cells,anti-CD59 stimulated-cells showed a higher level of proliferation and ZAP70 phosphrylation,while knocking down of CD59 led to the decreased cell proliferation and ZAP70 phosphorylation.In Junket-GFP cells,CD59 and LAT were mainly distributed in raftlaps of cell membrane after stimulated by CD59 antibody observed by confocal microscopy,while they were diffusly and uniformly distributed in unstimulated groups.Furthermore,CD59 showed a lower fluorescence intensity of Jurkat cells electroporated with pSUPER-siCD59 plasmids.The cells stimulated with anti-CD59 had a stronger level of cell proliferation and a higher level of phosphorylation-proteins compared with the others.Conclusion CD59 has a positive effect on T cell activation and proliferation,and CD59 contributed to LAT induced signaling transduction of T lymphocytes.