肿瘤患者CD8+T细胞中CD28表达的研究进展

CD28与B7结合形成的共刺激信号是T细胞激活的第二信号,肿瘤患者CD8^＋T细胞上CD28分子在肿瘤免疫中发挥着重要作用。人体抗肿瘤免疫主要由CD8^＋T细胞介导,根据CD28的表达与否可将CD8^＋T细胞分为细胞毒T细胞（CD8^＋CD28^＋,CTL）和抑制性T细胞（CD8^＋C28^-,Ts）。CTL是体内杀伤肿瘤细胞的主要功能性细胞之一,当该细胞与肿瘤接触时,通过共刺激信号而被激活,发挥其对肿瘤细胞的杀伤作用;Ts在机体的免疫耐受中发挥作用。现就肿瘤患者CD8^＋T细胞上CD28的表达作一综述。

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.