【摘要】 本研究探讨新型共刺激分子CD137(4-1BB)在人T淋巴细胞上的表达特点及其单克隆抗体hCD137mAb在刺激T淋巴细胞增殖、促进细胞因子分泌、增强细胞杀伤作用的抗白血病功能。应用FACS及间接免疫荧光法分别检测正常人T淋巴细胞上加入植物血凝素(PHA)前后不同时相CD137的表达。在HL-60细胞和T淋巴细胞体外培养体系中,用MTT比色法测定hCD137mAb、PHA对T淋巴细胞增殖作用的影响,用FACS及间接免疫荧光法检测其对T细胞表面上IFN-γ和IL-4分泌水平的影响。在体外混合淋巴细胞肿瘤细胞培养(MLTC)体系中,研究不同效靶比例时hCD137mAb增强T细胞杀伤白血病细胞的抗白血病作用。结果表明:①T细胞未经PHA刺激几乎不表达hCD137,经PHA活化后开始表达,且随着时间延长表达率逐渐增高,第7天为高峰(FACS法为56.4%±1.98%,间接免疫荧光法为52.8%±2.01%)。②MTT法检测提示,单独使用hCD137mAb不能刺激T细胞增殖(增殖指数1.002±0.011),但其与PHA伍用可增强后者刺激活性(增殖指数2.161±0.102)约2倍(增殖指数4.705±0.133)。③在PHA存在时,hCD137mAb可使IFN-γ在T细胞上表达增加到大约2倍,而对IL-4几无影响。④hCD137mAb明显增强T细胞对白血病细胞株HL-60的杀伤活性,且共刺激活性在40:1效靶比时最强,杀伤百分比增加到大约2倍。结论:新型共刺激分子CD137具有显著的抗白血病作用,应用hCD137mAb是一种有效排斥白血病的免疫策略,且安全、简便,本研究为其用于临床免疫治疗提供了实验依据。更多还原

【Abstract】 This study was aimed to investigate the expression characteristics of new co-stimulatory molecule CD137(4-1BB)on human T lymphocytes and antileukemic effects of monoclonal antibody hCD137mAb in stimulating the T lymphocyte proliferation,promoting the cytokine secretion,enhancing the cell killing effect and so on.The expression of CD137 on normal T lymphocytes treated with phytohemagglutinin(PHA) was detected by FACS and indirect immunofluorescence.In HL-60 and T lymphocyte system in vitro,the effect of hCD137mAb and PHA on T lymphocyte proliferation was tested by MTT colorimetric assay.The IFN-γ and IL-4 expression levels on the surface of T cells were detected by FACS and indirect immunofluorescence.In vitro mixed lymphocyte tumor cell culture(MLTC) system,the function of hCD137mAb enhancing toxicity killing leukemic cells at different effect-target ratio were studied.The results showed that almost no expression of hCD137 was found in T cells without PHA stimulation,but after activation of T cells by PHA,the expression gradually increased with a peak at 7th day(FACS 56.4%±1.98%,indirect immunofluorescence 52.8%±2.01%).CD137mAb alone could not stimulate T cell proliferation(proliferation index 1.002±0.011),but could enhance PHA stimulating activity(proliferative index of 2.161±0.102) about 2-folds(proliferation index 4.705±0.133).Moreover,hCD137mAb increased expression of IFN-γ high by about 3-fold in presence of PHA,but did not effect on IL-4.The hCD137mAb markedly enhanced T cell killing activity on HL-60 cell line and its co-stimulatory effect was best at the effect-target ratio of 40:1 with increasing of killing percentage by about 2-fold.It is concluded that the new co-stimulatory molecule CD137 has significant antileukemic effect,use of hCD137mAb is an effective,safe and simple immunization strategy for leukemia therapy,this study provides some experimental basis for clinical immunotherapy with CD137 mAb.更多还原