重组戊型肝炎病毒抗原免疫恒河猴及其对病毒攻击的保护  

Vaccination of Rhesus Monkeys with Recombinant Antigen Fragments and Protection from Hepatitis E Virus Infection

作　　者：马雁冰[1] 谢天宏[1] 张光明[1] 李春宏[1] 戴解杰[1] 戴长柏[1] 孙茂盛[1] 鲁健[2] 毕胜利[2] 

机构地区：[1]中国医学科学院中国协和医科大学医学生物学研究所分子生物学研究室,昆明650118 [2]Institute of Virology,CAPM,beijing100052

出　　处：《中国医学科学院学报》2002年第6期592-595,共4页Acta Academiae Medicinae Sinicae

基　　金：国家"九五"攻关课题(96-906-03-05)

摘　　要：目的了解重组抗原免疫恒河猴的抗体应答情况及其对病毒攻击的保护作用。方法利用大肠杆菌表达的戊型肝炎(HEV)病毒3个不同的片段,分别为Ag1(ORF2C端431aa)、Ag2(ORF2C端128aa片段)、Ag3犤ORF3122aa与ORF26287-6404碱基编码的39aa片段以及C端128aa依次以(Gly)n短臂连接的嵌合抗原犦免疫恒河猴,用ELISA方法检测IgG抗体水平,3周后达到较高水平应答时,用HEV阳性粪便样静脉注射进行攻击,经肝脏病理切片观察、血清IgG、丙氨酸转氨酶(ALT)水平测定及粪便排毒的RT-nPCR检测来评价抗原对病毒攻击的保护作用。结果对照组3只猴中两只发现肝脏组织产生明显的病理性改变,而免疫了抗原的试验组12只猴正常;对照组均在攻毒后3～4周发生ALT异常,为正常值的10～20倍,而试验组有部分猴不同程度轻微的ALT异常,其余正常;试验组免疫抗原后IgG水平迅速上升,滴度可达1∶12800;对照组粪便中病毒RNA的检出在攻毒后7～50d左右,而试验组7～21d内以低水平存在。结论重组的抗原片段诱发机体产生针对HEV的抗体应答,能够抑制HEV感染引起的肝炎症状的产生。Objective To observe anti-HEV IgG response to vaccination of recombinant an tigen fragments and evaluate its protection from Hepatitis E Virus infection in rhesus monkeys (Macaca mulatta).Methods Twelve monkeys were divided into thr ee groups and immunized respectively with three different recom binant antigen s:namely Ag1(carboxyl terminal431amino acids of ORF2),Ag2(128aa fr agment at the carboxyl terminal of ORF2),and Ag3(full length ORF3ligated with two ORF2fragments encoded by6743-7126nt and6287-6404nt) .The monkeys were challenged intravenously with fecal suspension from experimen tally infected rhesus monkeys,and the other three monkeys served as the placebo group for challenge with HEV.The dynamic changes of the levels of ALT and anti -HEV IgG were examined.Pathological changes of liver tissue were observed by li ght microscope.Excretion of virus was detected by RT-nPCR.Results Hepatic his topathology of two monkeys in the placebo group was consistent with acute vira l hepatitis,and ALT was elevated3～4weeks after inoculated with virus,up to 10～20times higher than normal level.The liver tissue of monkeys immunized with antigen kept normal,ALT in several monkeys elevated mildly,and anti-HEV IgG conversation occurred at1～2weeks after vaccination,with the titer reachi ng1∶12800.The virus RNA could be detected by RT-nPCR from days7to50in monkeys of control group,and from days7to21in vaccinated monkeys after challenged with virus.Conclusions The recombinant antigens could induce the production of anti-HEV IgG,which protected rhesus monkeys from acute Hepatitis symptoms related to HEV infection.

关 键 词：戊型肝炎病毒 戊型肝炎疫苗 抗体应答 抗原免疫 

分 类 号：Q78[生物学—分子生物学] R512.6[医药卫生—内科学]