HCA587蛋白疫苗的抗肿瘤效应及效应细胞亚群

The anti-tumor effect of HCA587 protein vaccine and its effector cell subsets

目的探讨HCA587蛋白疫苗对荷瘤小鼠的抗肿瘤效应并揭示抗肿瘤效应的免疫细胞亚群。方法在C57BL/6小鼠左侧胁腹部皮下接种肿瘤细胞建立肿瘤模型,给予HCA587蛋白疫苗等免疫策略治疗2次,观察抗肿瘤效果。用苏木精-伊红(HE)染色法分析疫苗治疗后肿瘤组织中淋巴细胞的浸润。用SDS-PAGE电泳分析自行制备的抗CD4和CD8分子单抗的相对分子质量和纯度,并用流式细胞术对其体内阻断效果进行鉴定。将上述单抗腹腔内注射入小鼠体内,以实现免疫细胞在体清除。结果与单一蛋白治疗组、佐剂对照组相比,HCA587蛋白疫苗具有显著的抗肿瘤作用(P<0.05)。在HE染色中,HCA587蛋白疫苗治疗后肿瘤局部可见大量的免疫细胞浸润。经流式细胞术鉴定,自行制备、纯化的抗CD4和CD8分子单抗在体能完全清除相应的CD4+T和CD8+T细胞亚群。当在体清除CD4+T细胞后,HCA587蛋白疫苗的抗肿瘤效应完全消失,而CD8+T细胞的清除不影响其抗肿瘤效应。结论 HCA587蛋白疫苗具有显著的抗肿瘤效应,其诱导的CD4+T细胞在抗肿瘤效应中起着至关重要的作用。

HCA587（also known as MAGE-C2） is a novel cancer-testis（CT） antigen that has been proved to highly express in a wide variety of malignancies, considered as an ideal target for tumor immunotherapy. In this study, we aimed to explore the anti-tumor effect of HCA587 protein vaccine and reveal the effector cell subsets in tumor-bearing mice. C57BL/6 mice were inoculated with tumor cells by subcutaneous injection on the left flank to establish tumor models, which were then treated with HCA587 protein vaccine for 2 times to observe the anti-tumor effect. Hematoxylin-eosin（HE） staining was used to analyze the infiltration of lymphocytes in tumor tissues. Molecular weight and purity of prepared anti-CD4 and anti-CD8 monoclonal antibodies were analyzed by SDS-PAGE electrophoresis and their blocking effects were identified in vivo by flow cytometry, then the antibodies were injected intraperitoneally into the mice to achieve complete depletion of immune cell subsets in vivo. Our data showed HCA587 protein vaccine could induce significant anti-tumor effect（P〈0.05）. After treatment of HCA587 protein vaccine, there were significant lymphocyte infiltrations in tumor tissues. When CD4＋T cells, not CD8＋T cells, were depleted in vivo, the anti-tumor effect of HCA587 protein vaccine completely disappeared. These results suggested that HCA587 protein vaccine can induce significant anti-tumor effect, in which CD4＋T cells play a critical role.