Objective: To investigate the distributions of GPI-anchored protein CD59 and C-terminal Src kinase-binding protein (Cbp) in cell membrane of T lymphocytes and the roles in cell activation and proliferation.
Methods: The locations of CD59 and Cbp were observed under a fluorescence microscope with the immunofluorescence cytochemistry. The Jurkat cells were transfected with the recombinant plasmid pSUPER-siCD59 using the electric transfection method. Using RT-PCR and Western blotting, we detected the expression of CD59 and the phosphorylation level of protein-tyrosine kinase oncogene family (fyn) in different groups. Moreover, the cell proliferation activity was measured by MTT assay.
Results: The immunofluorescence cytochemistry showed that CD59 and Cbp were mainly distributed in cell membrane. Compared with other groups, the quantitative RT-PCR and Western blotting showed that the expression of CD59 was reduced, and along with it the phosphorylation level of fyn decreased in pSUPER-siCD59 group, and MTT assay revealed that its cell proliferation was inhibited (P<0.05).
Conclusion: CD59 was a type of membrane-bound protein, CD59 and Cbp played synergistic roles in cell activation and proliferation.