猪细小病毒VP2蛋白的原核表达及其免疫原性评估

Prokaryotic expression and immunogenicity evaluation of porcine parvovirus VP2 protein

利用原核表达载体pET28a和pColdⅠ与猪细小病毒VP2基因分别构建重组表达质粒,并采用与伴侣蛋白共表达和低温诱导表达猪细小病毒VP2蛋白,并以电镜观察、血凝效价测定等进行鉴定。结果显示,2个表达载体均能对重组蛋白进行可溶性表达。冷休克载体组pColdⅠ-VP2蛋白在上清中表达效率更高且杂蛋白较少,诱导时不需要额外添加L-阿拉伯糖,表达过程工艺相对更简单。纯化后的pColdⅠ-VP2蛋白具有一定的免疫反应性,能在体外组装成病毒样颗粒(virus-like particles,VLPs),且具有血凝活性,使用206佐剂混合乳化重组蛋白免疫豚鼠后,血清中能检测到高滴度血凝抑制抗体。上述结果为进一步研究新型安全高效的猪细小病毒疫苗提供了数据支持。

Prokaryotic expression vectors pET28a and pCold I were used to construct recombinant expression plasmids with porcine parvovirus VP2 gene,and the recombinant protein of porcine parvovirus VP2 was co-expressed with chaperone protein and induced to express at low temperature,and identified by electron microscope and hemagglutination titer determination.The results showed that the recombinant protein could be expressed soluble by the two expression vectors.The cold shock vector recombinant protein pCold I-VP2 has a higher expression efficiency in the supernatant and fewer heteroproteins.It did not need additional L-arabinose during induction,and the expression process was relatively simple.The purified pCold I-VP2 recombinant protein had good immune reactivity,and could be assembled into virus like particles(VLPs)in vitro,and had hemagglutination activity.After immunizing guinea pigs with 206 adjuvant mixed with the emulsified recombinant protein,high titer of hemagglutination inhibition antibody could be detected in the serum.The above results provide data support for further research on new safe and efficient porcine parvovirus vaccine.