Antitumor effect of recombinant Mycobacterium smegmatis expressing MAGEA3 and SSX2 fusion proteins
Antitumor effect of recombinant Mycobacterium smegmatis expressing MAGEA3 and SSX2 fusion proteins
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DOI：
10.3892/etm.2018.6425
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发表时间：
2018-09-01
影响因子：
2.7
通讯作者：
Xue, Ying
中科院分区：
文献类型：
--
作者：
Jian, Wen;Li, Xin;Xue, Ying
污垢分枝杆菌是一种非致病性的快速生长的分枝杆菌，是一种潜在的表达异源抗原的疫苗载体。针对肿瘤/睾丸抗原(CTA)，包括黑色素瘤相关抗原A(MAGEA)和SSX，已经证明了自发的体液和细胞免疫反应。本研究构建了MAGEA3和SSX2的重组表达载体。将重组质粒转入耻垢分枝杆菌，制备新型抗肿瘤DNA疫苗。由于MAGEA3和SSX2的连接序列不同，两种DNA疫苗分别为重组耻垢分枝杆菌MAGEA3-SSX2(rM.S-MS)和重组耻垢分枝杆菌SSX2-MAGEA3(rM.S-SM)。Western blotting检测融合蛋白的表达水平。用rM.S免疫BALB/c小鼠，用免疫印迹法检测免疫小鼠是否产生抗MAGEA3或SSX2抗体。将EC9706细胞接种于BALB/c裸鼠体内，直到背部出现明显可见的肿瘤。然后，将rmS免疫的BALB/c小鼠的血液经尾静脉注入BALB/c裸鼠体内。为了评价疫苗的抗肿瘤效果，在注射后5~21d测量肿瘤体积和重量。于肿瘤生长第21天处死小鼠，解剖称量肿瘤。两种融合蛋白在rmS中表达，免疫BALB/c小鼠血液中表达特异性融合蛋白抗体。重组耻垢分枝杆菌MAGEA3(rM.S-M)和重组耻垢分枝杆菌SSX2(rM.S-S)组的肿瘤体积和重量均明显小于对照组。此外，rM.S-MS组和rM.S-SM组的肿瘤体积和重量的减少比rM.S-M组和rM.S-S组更严重。RM.S-MS组和rM.S-SM组的抗肿瘤作用无明显差异。目前的研究结果表明，该rmS可能是一种潜在的治疗癌症的候选疫苗。
Mycobacterium smegmatis (M. smegmatis), which is a nonpathogenic and fast-growing mycobacterium, is a potential vaccine vector capable of expressing heterologous antigens. Spontaneous humoral and cellular immune responses have been demonstrated against cancer/testis antigens (CTA), including melanoma-associated antigen A (MAGEA) and SSX. In the present study, recombinant plasmids expressing MAGEA3 and SSX2 were constructed. The recombinant plasmids were transferred into M. smegmatis to generate the novel antitumor DNA vaccine. As MAGEA3 and SSX2 were in different ligation sequences, the two DNA vaccines were recombinant M. smegmatis MAGEA3-SSX2 (rM.S-MS) and recombinant M. smegmatis SSX2-MAGEA3 (rM.S-SM), respectively. The expression levels of Fusion proteins were assessed by western blotting. BALB/c mice were immunized with rM.S and western blot analysis was used to determine whether antibodies against MAGEA3 or SSX2 were produced in immunized mice. EC9706 cells were inoculated into BALB/c nude mice and the mice were maintained until an obvious visible tumor appeared on the back. Subsequently, the blood from the rM.S immunized BALB/c mice was injected into the BALB/c nude mice via the tail vein. In order to evaluate the antitumor effect of the vaccines, tumor volume and weight were measured 5 to 21 days after injection. Mice were euthanized on day 21 of tumor growth, and the tumor was dissected and weighed. The two fusion proteins were expressed in the rM.S and the specific fusion protein antibodies were expressed in the blood of immunized BALB/c mice. The tumor volumes and weight in the recombinant M. smegmatis MAGEA3 (rM.S-M) and recombinant M. smegmatis SSX2 (rM.S-S) groups were significantly reduced compared with the control group. Furthermore, the decrease in tumor volumes and weight in the rM.S-MS and rM.S-SM groups was more severe than in the rM.S-M or rM.S-S groups. There was no significant difference in the antitumor effect of the rM.S-MS and rM.S-SM groups. The present findings suggest that this rM.S may be a potential candidate therapeutic vaccine for the treatment of cancer.