CD4^+T细胞克隆特异性杀伤自体的非霍奇金淋巴瘤相关机制的研究

Mechanism of cytotoxicity mediated by autologous tumour-specific CD4^+ T-cell clones against B-cell non-Hodgkin's lymphoma

目的:研究CD4+T细胞克隆特异性杀伤自体非霍奇金淋巴瘤的相关机制。方法:以患者自体恶性淋巴瘤细胞株(M-CH1细胞)为刺激源,培养得到具有特异杀伤性的CD4+T细胞,采用细胞毒试验、细胞毒抗体封闭试验及细胞流式等技术,研究该CD4+T细胞特异杀伤肿瘤的机制。结果:得到的3个特异的CD4+T细胞克隆(5.1、10.4和40.1)均可通过人类白细胞抗原(HLA)-Ⅱ分子中HLA-DP依赖途径杀伤M-CH1细胞。经流式细胞仪分析,证实这些CD4+T细胞克隆并非自然杀伤T细胞(NKT细胞)来源。concanamycin A(CMA)和乙二醇双(2-氨乙基醚)四乙酸(EGTA)能够阻断这些T细胞克隆的特异性肿瘤杀伤作用。同时,这些CD4+T细胞克隆能高表达穿孔素和颗粒酶。结论:在该研究体系中,CD4+T细胞克隆特异性杀伤自体非霍奇金淋巴瘤的机制主要是通过HLA-DP限制性的穿孔素途径。

Objective To investigate the mechanism of cytotoxic efficacy of CD4^＋ T cells in B cell non-Hodgkin＇s lymphoma （NHL）. Methods CD4^＋ T cells incubated with the autologous lymphoma tumor cells were used to reveal the underlying specific cytotoxic mechanism. Cytotoxicity assays, inhibition studies and cytometry were carried out. Results The clones （5.1, 10.4 and 40.1） were capable of killing the autologous HLA- Ⅰ deficient M-CH1 cells via a classic HLA- Ⅱ restricted antigen recognition. The results of flow cytometry demonstrated that these clones were not derived from natural killer T cells （NKT cells）. Concanamycin A （CMA） and ethylene glycolbis （2-aminoethyl ether）-N, N, N＇, N＇- tetraacetic acid inhibited the cytotoxicity of these clones. Meanwhile, high levels of intracellular perforin and granzyme were identified in these CD4^＋ T clones. Conclusions This study demonstrate that cloned CD4^＋ T cells are not derived from NKT cells, and lysis is specific to corresponding tumour antigen presented by HLA-DP molecules. Perforin-mediated pathway might be the major mechanism of cytotoxicity.