【摘要】 过去的研究发现大肠杆菌表达的戊型肝炎病毒 （HEV）衣壳蛋白ORF2的aa3 94₆0 6片段NE2可以形成同源多聚体 ,并具有良好的免疫保护性 ,但纯化后的免疫原性较弱。这里表达了 3个NE2蛋白的N端延伸突变体 ,发现对应于ORF2aa3 68₆0 6的重组蛋白HEV 2 3 9在体外可以形成颗粒性抗原。HEV 2 3 9抗原颗粒与戊肝患者血清反应性良好 ,对中和性单克隆抗体 8C11的反应性与NE2抗原相当 ,而对另一中和性单克隆抗体 8H3的反应性较NE2抗原有显著提高 ,表明HEV 2 3 9抗原颗粒具有比NE2更好的抗原性。纯化后的HEV 2 3 9抗原颗粒直径约为 15～3 0nm。铝佐剂吸附的HEV 2 3 9免疫Balb c小鼠的半数有效剂量 （ED5 0 ）在 0 0 8～ 0 2 5μg之间 ,而同样以铝佐剂吸附的NE2抗原 60 μg剂量免疫的抗体阳转率仅 2 5% ,表明HEV 2 3 9抗原颗粒具有更好的免疫原性更多还原

【Abstract】 An E.coli expressed recombinant antigen NE2 was reported to aggregate into homo_oligomer, and can induce protective ant ibodies on rhesus monkey, but its immunogenicty was much weak after being puri fied. In this study, three N_terminal extension mutant of NE2 were expressed in E.coli, one of which named HEV 239 was found to aggregate into particle. HEV 239 antigen had good reactivity with sera of hepatitis E patients. The reactivity of HEV 239 against neutralization monoclonal antibody 8C11 was s imilar as NE2 antigen, while the reactivity of it against another neutralization monoclonal antibody 8H3 is much better than NE2 antigen, which indicated better antigenicity of HEV 239 than NE2 The diameter of purified HEV 239 particulate antigen was between 15 nm to 30 nm. The ED 50 of immunization of HEV 239 p article adsorbed by aluminum adjuvant to BALB/c mice was between 0 08 μg to 0 25 μg.In contrast, the seraconversion rate of mice immunized by NE2 antigen a dsorbed by aluminium adjuvant was only 25% on 60 μg vaccination. These results suggested that HEV 239 antigen particle has better immunogenicity as well as ant igenicit y than those of NE2 antigen, so it is a better vaccine candidate against HEV.更多还原