Advances on Expression of CD28 Molecules on CD8~+ T Cells in Peripheral Blood of Cancer Patients

CD28 is one of the most important costimulators for T cell activation through binding with BT.CD28 molecule on CD8+T cell plays a key role in cancer immunity.CD8~+T cells are the main cells mediating anti-tumor immune response.Ac- cording to expression or absence of CD28 molecule on CD8~+T cells,CD8~+T cells are divided into two subsets:cytotoxic T cell (CD8~+CD28~+,CTL)and suppressor T cell(CD8~+C28~-,Ts).CTL is one of main cells killing tumor cells in vivo:after CTL touched tumor cell,it was activated by cosfimulatory signal,produced a marked effect in tumor cell.Ts plays an important role in immune tolerance.In peripheral blood of tumor patients,it was said,CTL cells count commonly decreased,while Ts cells often increased. The tumor patients were in immunologic derangement.Immune fimction in patients with cancer could be recovered to a certain lev- el through cutting down tumor,but reports on immune function after chemotherapy didn't all coincided with that.In this artide, we review the expression of CD28 molecule on CD8~+T cells in peripheral blood of cancer patients.Studies on CD28 molecules will offer a new thinking to immunological regulation and immunologic intervention.That is conducive to discovery of pathogenesis. Furthermore,it may be an objective indicator of therapy and therapeutic effect of tumor.