戊型肝炎病毒ORF2N-端和C-端多肽的抗原性分析

Analysis of Antigenicity of Polypeptides at N-and C-terminus of ORF2 of Hepatitis E Virus

目的分析戊型肝炎病毒(HEV)ORF2N-端和C-端多肽的抗原性。方法以纯化的4型HEVORF2N-端1～124aa多肽pS4-1和4型HEVORF2C-端385～674aa多肽pS4-6分别包被微孔板,采用间接酶联免疫法(EIA)检测感染HEV的猴系列血清中的抗HEVIgG抗体,分析两种多肽的抗原性,并与进口试剂的检测结果进行比较。结果在感染HEV的猴系列血清中,针对HEVORF2N-端抗原的抗体产生时间早,持续时间短,其峰值与转氨酶(ALT)的峰值几乎重叠;针对HEVORF2C-端抗原的抗体在HEV感染早期产生的滴度较低,但逐渐升高,在14周的观察期内,抗体滴度几乎无下降趋势。用两种多肽检测HEVIgG抗体的灵敏度均高于进口试剂。结论两种多肽均具有较好的抗原性,但在HEV感染的不同时期,其反应性不同。

Objective To analyze the antigenicity of polypeptides at N- and C-terminus of ORF2 of hepatitis E virus （HEV）. Methods Microtiter plate was coated with the polypeptide pS4-1 at N-terminus and the polypeptide pS4-6 at C-terminus of type 4 HEV ORF2 respectively and used for determination of anti-HEV IgG in a series of serum samples of monkeys infected with HEV by EIA, based on which the antigenicity of the two polypeptides were analyzed, and the determination results were compared with those by imported kit. Results In a series of serum samples of monkeys infected with HEV, the IgG against antigen at N-terminus of HEV ORF2 appeared early and last for a short time, and its peak value appeared almost at the same time with that of ALT. However, the IgG titer against antigen at C-terminus of HEV ORF2 was low at early stage of infection, while increased gradually and showed almost no decreasing tendency during the observation period of 14 weeks. Both the sensitivities of HEV IgG kits prepared with polypeptides pS4-1 and pS4-6 were higher than those of imported kit. Conclusion Both pS4-1 and pS4-6 showed good antigenicity, while showed different reactogenicity at various stages of HEV infection.