论文部分内容阅读
目的 利用减毒鼠伤寒沙门氏菌研制胃癌MG7 Ag模拟表位的口服DNA疫苗 ,并观察其对小鼠的免疫效能及保护作用。方法 构建MG7 Ag模拟表位和通用性辅助性T细胞表位融合基因的真核表达载体。将真核表达载体转入减毒鼠伤寒沙门氏菌得到模拟表位的口服DNA疫苗。以 1× 10 8cfu疫苗菌口服免疫C5 7BL/6J小鼠 ,以携带空载体的沙门氏菌和PBS口服作为对照。以ELISA法检测小鼠血清中抗MG7 Ag抗体的滴度 ,以H TDR掺入法检测小鼠脾淋巴细胞对人工合成的MG7 Ag抗原肽刺激的增殖能力。同时 ,用表达MG7 Ag的小鼠艾氏腹水瘤细胞进行肿瘤攻击 ,观察疫苗对小鼠的保护作用。结果 口服疫苗可诱导小鼠产生MG7抗体 ,但各组小鼠脾淋巴细胞体外刺激增殖实验差异无显著性。肿瘤攻击 2周后 ,疫苗免疫组 7只小鼠中有 2只未见肿瘤形成 ,而对照组 4只小鼠则全部成瘤。结论 胃癌MG7 Ag模拟表位的口服DNA疫苗具有免疫原性 ,可以诱导小鼠产生抗肿瘤免疫 ,并具有一定保护作用
OBJECTIVE: To develop an oral DNA vaccine against gastric cancer MG7 Ag mimotopes using attenuated Salmonella typhimurium and to observe its immunological efficacy and protective effect on mice. Methods Construction of eukaryotic expression vector of MG7 Ag mimotope and universal helper T cell epitope fusion gene. The eukaryotic expression vector was transferred into attenuated Salmonella typhimurium to obtain a mimotope oral DNA vaccine. The C5 7BL / 6J mice were orally immunized with 1 × 10 8 cfu vaccine bacteria and orally administered with Salmonella carrying the empty vector and PBS as a control. The titer of anti-MG7 Ag antibody in serum of mice was detected by ELISA. The proliferative ability of mouse spleen lymphocytes stimulated by synthetic MG7 Ag antigen peptide was detected by H TDR incorporation. At the same time, mice were challenged with Ehrlich ascites tumor cells expressing MG7 Ag to observe the protective effect of the vaccine on mice. Results Oral vaccine induced the production of MG7 antibody in mice, but there was no significant difference in the proliferation of splenic lymphocytes stimulated in vitro. Two weeks after the tumor attack, two of the seven mice in the vaccine-immunized group showed no tumor formation, whereas the four mice in the control group all formed tumors. Conclusion The oral DNA vaccine of gastric cancer MG7 Ag mimotope has immunogenicity and can induce anti-tumor immunity in mice and has certain protective effect