搭载小鼠IL-33重组溶瘤病毒的构建及其对肿瘤协同抑制作用的研究

Construction of mouse IL-33-armed recombinant oncolytic virus and its synergistic inhibitory effects on tumor

目的 构建重组溶瘤病毒vvmIL33,靶向感染肿瘤细胞后能稳定分泌小鼠IL-33蛋白（mIL-33）,同时研究观察其对肿瘤的协同抑制作用.方法 采用PCR法扩增小鼠IL-33基因序列,将其插入真核表达载体中构建pCMS1-mIL33重组子;脂质体法将重组子导入已被亲本溶瘤病毒（vJS6）感染的细胞内,重组获得重组溶瘤病毒vvmIL33,经流式分选、纯化重组溶瘤病毒;酶联免疫吸附法（ELISA）检测vvmIL33感染肿瘤细胞后培养上清中mIL-33蛋白的含量;重组溶瘤病毒vvmIL33和亲本病毒vJS6分别感染肿瘤细胞,通过空斑形成试验和MTS试剂盒分别检测溶瘤病毒的复制能力及其对肿瘤细胞的溶解能力;经T细胞共培养实验观察vvmIL33感染肿瘤细胞后诱导T细胞的抗肿瘤能力.结果 重组子pCMS1-mIL33酶切电泳结果表明成功插入了mIL-33基因;与对照组相比,vvmIL33感染MC38细胞后能高剂量稳定分泌mIL-33蛋白;空斑形成试验结果显示vvmIL33或vJS6感染CV1、MC38细胞在各个时间点产生相似量的病毒,差异无统计学意义（P〉0.05）;不同感染复数下（MOI）,vvmIL33感染后对肿瘤细胞的溶解能力与vJS6相似,差异无统计学意义（P〉0.05）;经T细胞共培养实验后发现,相比较vJS6组,vvmIL33感染MC38细胞组中T细胞所产生的INF-γ蛋白浓度明显升高（P〈0.05）,同时诱导T细胞对肿瘤细胞的杀伤作用也明显增强（P〈0.05）.结论 成功构建了重组溶瘤病毒vvmIL33,mIL-33的表达不损害溶瘤病毒的复制能力和诱导杀肿瘤细胞溶解的能力,溶瘤病毒搭载mIL-33增强了T细胞的免疫效应,增加了抗肿瘤作用.

Objective To construct a recombinant oncolytic virus vvmIL33 that can steadily se-crete mouse IL-33 protein （mIL-33） in targeted tumor cells and to study its synergistic inhibitory effect on tumor. Methods Mouse IL-33 gene sequence was amplified by PCR and inserted into the eukaryotic ex-pression vector pCMS1. The constructed pCMS1-mIL33 was transfected into the parent virus （vJS6）-infected cells by Lipofactamine. Recombinant oncolytic virus vvmIL33 was purified by cell flow sorting. Enzyme-linked immunosorbent assay （ ELISA） was used to detect the level of mIL-33 protein in the culture superna-tant of vvmIL33-infected tumor cells. Recombinant oncolytic virus vvmIL33 and parental virus vJS6 were re-spectively used to infect tumor cells, and then analyzed by plaque formation assay and MTS kit. T cell co-culture experiments were performed to examine the anti-tumor ability of T cells induced by vvmIL33-infected tumor cells. Results Electrophoresis results of the recombinant plasmid pCMS1-mIL33 showed that mIL-33 gene was inserted successfully. Compared with the control group, vvmIL33 could steadily secrete high levels of mIL-33 protein in MC38 cells after infection （P〈0. 001）. Results of the plaque formation assay showed that vvmIL33-or vJS6-infected CV1 and MC38 cells produced similar amounts of virus at various time points without statistical difference （P〉0. 05）. Under different multiplicity of infection （MOI）, the lytic ability of vvmIL33 against tumor cells was similar to that of vJS6 without statistical difference （P〉0. 05）. In the T cell co-culture experiments, the concentration of INF-γ protein produced by T cells in the vvmIL33-infected MC38 cell group was significantly increased as compared with that of the vJS6 group （P〈0. 05）. Moreover, the cytotoxic effect of induced T cells on tumor cells was also significantly increased （P〈0. 05）. Conclusion The recombinant oncolytic virus vvmIL33 was successfully constructed without damaging its ability to repli-cate and induce tumor cell lysis. Oncolytic virus carrying mIL-33 enhanced the immune effect of T cells and increased anti-tumor effect.