[Localization and function of CD59 and Cbp in T lymphocytes].

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.