异种表皮生长因子受体胞外段的表达及其抗肿瘤效果研究

目的:构建异种EGFR蛋白疫苗并研究其抗肿瘤效果.方法:用PCR方法获得鸡EGFR胞外片段, 与pGEX- 4T-2载体连接, 并在E.coli BL21(DE3)中表达鸡的EGFR胞外片段与GST的融合蛋白, 融合蛋白经Ni2 亲和层析柱纯化、复性后, 免疫小鼠, 免疫3次后, 接种小鼠Lewis细胞, 观测肿瘤生长情况, ELISA检测小鼠血清中抗EGFR蛋白的抗体效价.结果:成功构建了EGFR胞外段基因的原核表达载体; SDS-PAGE显示成功表达了目的融合蛋白; 融合蛋白免疫小鼠后, ELISA法检测到特异性抗EGFR抗体; 实验组与对照组肿瘤体积的比较结果显示, 融合蛋白疫苗能够在一定程度上抑制肿瘤的生长.结论:异种EGFR蛋白能够克服免疫耐受问题, 诱导机体产生抗体, 有一定的抗肿瘤效果, 为后续的肿瘤疫苗研究打下了基础.

Expression of xenogentic epidermal growth factor receptor ectodomain and its antitumor effect

AIM: To construct the EGFR protein vaccine and evaluate its antitumor effect. METHODS: The gene of chicken EGFR ectodomain was amplified by PCR, inserted into the pGEX-4T-2 vetor, and then exporessed in E.coli BL21 with glutathione S-transferase in a fusion protein form. The fusion protein was purified by metal affinity chromatography, and refolded by dialysis.Then the mice were immunized with the fusion protein three times. After that, these mice were vaccinated with Lewis cells. At last the growth of tumors was measured and the surm antibody response was measured by ELISA. RESULTS: The ectodomain gene of EGFR was ligated into prokaryotic expression vetor. The expression of the fusion protein was analyzed by SDS-PAGE. The relative moleclar mass of the protein is about Mr 50 000. After the third immunization, all the mice immunized with the fusion protein showed an antibody response towards the EGFR protein. Compared with the control group, the fusion protein group showed good anti-tumor effects. CONCLUSION: The xenogentic EGFR protein vaccine can overcome the host's immune tolerance problem and induce the production of specific antibodies against.