Targeted killed Raji cells by anti-CD20scFv-Fc-CD28/ζ modified T lymphocyte

Abstract

Objeotive To investigate the target killing effect off Raji cells with anti-CD20scFv-FcCD28/ζ gene chimeric T lymphocytes and the activation of T lymphocytes and further approach the mechanism of gene chimeric T lymphocytes target killing lymphoma cells.Methods The plasmids were transfected into retrovirus-packed PA317 cell lines by liposome.The supernatant wills collected from successfully transfected PA317 cells,then co-cultured with T lymphocytes,screening with G418 800μg/ml for 1 week.T-lymphocytes co-culture was grafted with Rail cell lines.the Bcl-2 of Raij cells were examined at timecourse by FACS.the level of IL-10 and IFN-γ was determined by ELISA.Results The Bcl-2 rate had obviously decreased within 24 h in Raii cells.the decreased amplitude was from 98.43%to 38.45%within 72 h.which is significant higher than that in control group and blank group.We found the IL-10 was 100.30 pg/ml in test group at 72 h,which was lower than that in control group(210.88 pg/ml)and blank group (286.71 pg/ml).At the same time IFN-γ(1487.23 pg/ml)was higher than that of other groups.Conclusion Anti-CD20-mediated T cells target lysis Rail cells does not require CD28 costimulation.T cells can enhanced inhibited the IL-10 secretion of Raji by CD28 and CD3ζ costimulation,and also decrease the Bcl-2 of Raji,thereby it accelerates the target cell lysis.CD28/ζ can completely activate T cell without exogenous B7/CD28 costimulation,which furthermore promote T lymphocyte secretion IFN-γ and can also enhance the targeted killing activity of T lymphocytes to Rail cells. Key words: Lymphoma; T lymphocyte; lmmunotherapy