EGFR基因重组T7噬菌体疫苗抗Lewis肺癌的实验研究

本研究中制备了表达表皮生长因子受体（EGFR）部分肽段的基因重组T7噬菌体疫苗，并开展了诱导小鼠产生内源性抗EGFR抗体的实验性抗肿瘤作用研究。由T7噬菌体展示系统将7个经筛选的异种属（人源、鸡源）EGFR膜外区片段展示在其壳体次要头蛋白（P10B）上，用所制备的基因重组噬菌体疫苗免疫小鼠，免疫4W后皮下接种Lewis肺癌细胞，10d后分离瘤体并称重，观察各实验组的抗肿瘤效果。WesternBlot检测重组的融合壳蛋白均有EGFR抗原性：高表达EGFR的A431细胞与免疫3W的小鼠抗血清结合并被荧光二抗标记．流式细胞仪检测法确认有抗EGFR抗体产生；各实验组肿瘤均重统计结果显示，P—CL1—670组、P—cp1-130组、P—cp2—136组、P—cp3—145组、P—cp4—142组与空白噬菌体组差异性显著。说明表达EGFR的基因重组噬菌体疫苗诱导产生的内源性抗体，在一定程度上抑制了EGFR阳性肿瘤的生长，为诱导型内源性抗EGFR抗体的肿瘤靶向治疗研究开辟了新的途径。

AN ANTI-TUMOR RESEARCH OF RECOMBINANT PHAGE VACCINE EXPRESSED XENOGENIC EGFR

A recombinant phage vaccine expressing EGFR on it's capsid was constructed and used to study the anti-tumor effect. The T7 phage display system was applied to display seven xenogenic (human, chicken) epidermal growth factor receptor extracellular domain fragments. The EGFR fragment was expressed as fused protein with 10B capsid on the surface of T7 phage. The T7-EGFR phage vaccines were injected into C57BL/6J mice, and then Lewis lung cancer cells were inoculated after 4 weeks immunization. The tumor tissue was excised and weighed after 10 days to evaluate the anti-tumor effect of each experimental group. The EGFR expression of the phage vaccine was verified by western-blot analysis. The A431 cells with high expressed EGFR was used to detect the anti-EGFR antibody by flow cytometry analysis. The results showed that the A431 cell can react with the serum obtained from the mice after three-week immunization. The experimental results confirmed that special EGFR antibody could be induced by the T7-EGFR phage vaccine. The T7-EGFR phage vaccine can elicit endogenous special EGFR antibody in mice and is capable of suppressing the tumor proliferation and retarding the growth of Lewis lung cancer. This research can be used to develop an anti-tumor vaccine for the target-therapy of EGFR(+) tumor.