关键词: 猪细小病毒, VP2蛋白, 病毒样颗粒, 疫苗, 免疫评价

Abstract: In order to develop porcine parvovirus(PPV) virus-like particles(VLPs) vaccine,the VP2 gene of PPV was optimized according to the preference codon usage of Escherichia coli (E.coli) and synthesized.Subsequently,the synthesized VP2 gene was subcloned into pET28a and transformed into BL21(DE3),then the partner protein plasmid,pTf16,was transformed into the BL21(DE3) competent cell containing pET28a-VP2.The objective gene was induced by L-arabinose and IPTG,its product was identified by SDS-PAGE and Western blot, and then the optimization of expressed condition, and distribution analysis of objective protein were done.The results indicated that,the expression quantity of soluble recombinant VP2 protein was highest after induced by 2 mg/mL L-arabinose and 0.1 mmol/L IPTG at 30 ℃ for 12 h.The recombinant VP2 protein was purified by ammonium sulfate precipitation and Ni-NTA affinity chromatography,and the purity was about 90%.The VLPs about 20 nm were obtained,which could hemagglutinate red blood cell.And then Kunming mice were immunized with purified VLPs.The results showed that the prepared VLPs vaccine could effectively stimulate the body to produce high titer antibodies(the titer of antibodies was up to 1∶25 600 by ELISA).Preliminary results showed that the prepared VLPs vaccine could stimulate body to produce specific antibody.

Key words: Porcine parvovirus, VP2 protein, Virus-like particles, Vaccine, Immunization evaluation