hCGβ-C3d3融合蛋白免疫BALB/c小鼠及其抗血清对hCG诱导鼠子宫增重的抑制效应

目的:通过分子佐剂C3d3增强hCGb避孕疫苗的免疫原性。方法:采用分子生物学技术以phCMV1为载体分别构建分泌型、带有6个组氨酸纯化标签的真核表达质粒phCMV1-6His-hCGb-C3d3和phCMV1-6His-hCGb,在CHO细胞中获得稳定、高效表达的重组蛋白,并用镍柱和凝胶过滤层析对其进行分离、纯化。分别用hCGb-C3d3融合蛋白和单用hCGb间隔4周两次免疫生育期雌性BALB/c小鼠,ELISA测定血清中抗hCGb抗体滴度,并对各组小鼠产生的抗血清拮抗hCG诱导的小鼠子宫增重效应进行比较。结果:C3d3使hCGb蛋白疫苗的免疫原性增强1 995倍,hCGb-C3d3融合蛋白免疫小鼠产生的抗血清具有很强的抑制小鼠子宫增重作用。结论:通过分子佐剂C3d3可以大幅提高机体对hCGb的体液免疫应答能力,hCGb-C3d3融合蛋白免疫小鼠产生的抗血清对hCG的生物学作用具有更强的抑制效应。

Immunization of BALB/c Mice with hCGβ-C3d3 Fusion Protein and Inhibiting Effect of Its Antiserum on hCG-induced Uterus Weight Increase of Immature Mice

Objective: To enhance the immunogenicity and the hCG-neutralization of hCGb protein vaccineby fusing to the molecular adjuvant C3d3. Methods: The secreted 6his-hCGb-C3d3 fusion protein and 6his-hCGbwere expressed in CHO cells and purified with Ni2+-chelating chromatography and Sephadex G-150 column. Theanti-hCG antibody response of the hCGb-C3d3 fusion protein immunization was compared with that of immuniza-tion with hCGb alone in BALB/c mice. The increase of weight of hCG-induced murine uterus was used to investi-gate the hCG-neutralizing capacity of anti-hCGb antiserum. Results: The anti-hCGb antiserum titer of hCGb-C3d3 immunization was 1995-times higher than that of immunization with the hCGb alone, and the former wasmore effective than the latter in inhibiting the increase of hCG-induced murine uterus weight. Conclusion: C3d3conjugates may be used to improve the immunogenicity and anti-fertility effectiveness of the hCGb contraceptivevaccine.