抗人CD28激发性单抗对T细胞淋巴瘤的抑制作用研究

Provocative mouse-anti-human monoclonal antibody against human CD28 inhibits growth of T cell lymphoma

目的:研究鼠抗人CD28单克隆抗体(克隆号:2F5)对T淋巴细胞瘤的抗肿瘤效应,为抗体介导肿瘤靶向治疗提供新的方法和思路。方法:流式细胞术检测鼠抗人CD28单克隆抗体2F5对人T淋巴瘤细胞株Jurkat细胞表面膜型CD28分子的识别;MTT法检测2F5对Jurkat细胞体外增殖的影响;将Jurkat细胞株接种于裸鼠腋下,建立Jurkat细胞荷瘤裸鼠模型;经瘤内多点注射2F5(注射剂量1μg/mm3),逐日观察肿瘤的大小和裸鼠的生存状态。结果:2F5能够识别Jurkat细胞表面CD28分子,阳性结合率可达93.37%;2F5与Jurkat细胞共培养后,显微镜下观察可见胞质中出现黑色颗粒,胞膜破裂,细胞的折光性和立体感减弱;MTT法分析结果显示,抗CD28单抗对Jurkat细胞的体外增殖具有明显的抑制作用;将Jurkat细胞接种35只裸鼠(成瘤率达70%);经瘤内多点注射2F5,35天后荷瘤小鼠体内肿瘤的生长速率明显降低;而生理盐水对照组肿瘤生长无明显改变。结论:鼠抗人CD28单克隆抗体2F5通过与Jurkat细胞表面膜型CD28分子结合对其增殖具有明显的抑制作用,提示CD28分子可作为治疗T淋巴瘤的一个潜在靶点,抗体对治疗CD28分子阳性的肿瘤具有潜在临床应用价值。

Objective：Effect of mouse-anti-human Mab against human CD28,clone No.2F5,（hereafter referred as 2F5） on inhibition of T cell lymphoma was investigated,which may possibly provide creative methods in antibody mediated targeted therapy.Methods：Recognition of 2F5 with surface molecule CD28 on Jurkat cell,one of T lymphoma cell lines,was examined by flow cytometry.Effect of 2F5 on Jurkat proliferation in vitro was examined through MTT assay.Jurkat cells were inoculated at armpit of naked mouse in order to establish mouse model of bearing Jurkat tumor.Tumorbearing mouse was multitude intratumorally injected with 2F5 in 1 μg/mm3.Size of tumor was observed every day and was examined every week.General condition of naked mouse was observed by routine.Results：2F5 could recognize surface molecule CD28 on Jurkat cell,with positive recognition rate of 93.37%.Jurkat cell was observed aggregation and its periplast was observed with black particles.Refraction and three-dimension feature was weakened.Results of MTT assay showed that CD28 had obvious inhibition effect on proliferation of Jurkat cell in vitro.Naked mice that were inoculated Jurkat cells were 35 in total,among which 24 mice have grown apparent tumors after a month.Average volume of tumor was 20 mm3 and tumor growth rate was 70%.Growth rate of tumor of medication group that were intratumorally injected with 2F5 was apparently reduced,while in control group injected with saline it was almost the same.Conclusion：2F5 had obvious inhibition effect on proliferation of Jurkat cell through binding with its surface molecule CD28,therefore,CD28 could become a potential target in T lymphoma therapy and the antibody had potential clinical application value in therapy of tumor expressing surface molecule CD28.