携带flk-l的减毒沙门疫苗菌抗胶质瘤血管生成的研究

目的观察表达鼠血管内皮生长因子受体2(VEGFR2,flk-1)的重组减毒鼠伤寒沙门疫苗菌对胶质瘤荷瘤小鼠的抗肿瘤血管及肿瘤生长抑制作用。方法构建真核表达载体pcDNA3 1.-flk-l,通过电转化法将pcDNA3 1.-flk-1导入减毒鼠伤寒沙门菌SL7207中,经由胃管饲于C57BL/6J小鼠,对胶质瘤荷瘤小鼠进行免疫预防及治疗。通过观察免疫动物的生存期,免疫荧光法检测肿瘤血管密度,评价重组疫苗菌的抗血管及肿瘤生长抑制作用。分离免疫小鼠的脾细胞,分析重组疫苗菌免疫后小鼠体内的特异性细胞毒性T细胞(CTL)应答。结果重组疫苗菌免疫能够明显减少肿瘤血管密度,延缓胶质瘤的生长,延长小鼠生存期,获得明显的抗肿瘤效果。重组疫苗菌免疫后可诱导小鼠脾淋巴细胞产生针对flk-l的CTL活性。结论表达鼠flk-l的重组减毒鼠伤寒沙门疫苗菌经口服免疫,可打破小鼠对于自身抗原flk-1的免疫耐受,诱导小鼠产生抗flk-1的特异性免疫反应,特异性杀伤肿瘤血管内皮细胞,预防和治疗小鼠胶质瘤。

Anti-glioma Effect of Attenuated Salmonella typhimurium Vaccine Strain with flk-1 Gene

Objective To investigate the anti-vasculature effects and the anti-glioma effects of attenuated Salmonella typhimurium vaccine strain expressing VEGFR(flk-1) gene.Methods Plasmid pcDNA3.1-flkl was constructed and elect-transfected into live attenuated Salmonella typhimurium strain SL7207.Mouse models of intracranial Gl261 glioblastoma were treated with an orally administered attenuated Salmonella typhimurium expressing flk-1 gene.The survival was observed and vessel density was measured by immunofluorescence.CTLs activity was measured by MTT assay.Results Attenuated Salmonella typhimurium vaccine strain expressing flk-1 gene could evidently inhibit glioblastoma growth,prolong the survival time and increasethe survival rate in these mice.The flk-1 specific CTLs activity was increased obviously after vaccine strain vaccination.Conclusion Attenuated Salmonella typhimurium vaccine strain expressing flk-1 gene can break peripheral immune tolerance against this self antigen and kill vascular endothelial cells by an oral administration and is useful for both prophylactic and therapeutic purposes.