重组人源抗狂犬病毒单克隆抗体鸡尾酒暴露后预防效果评价

Development of Recombinant Human Monoclonal Antibody Cocktail for Postexposure Rabies Prophylaxis

本研究对重组人源抗狂犬病毒单克隆抗体鸡尾酒暴露后预防效果进行评价,选用狂犬病毒国内代表性疫苗株、实验室固定毒株及街毒株共11株病毒,通过荧光抗体病毒中和试验(FAVN)分析针对狂犬病毒糖蛋白Ⅰ、Ⅱ、Ⅲ号表位的三株单抗CR57(I)、RV08(II)和RV3A5(Ⅲ)及其鸡尾酒配伍的中和谱,在此基础上选用狂犬病病毒标准攻击毒株CVS-11感染仓鼠腓肠肌,进一步研究重组人源抗狂犬病毒单抗及其鸡尾酒制剂暴露后保护效果,结果显示CR57、RV08、RV3A5及其三联配伍制剂对11株狂犬病毒均具有明确的中和作用,按中和效价1∶1∶1配伍组成的鸡尾酒组合制剂对这些毒株的中和能力没有减弱,表明三株抗体间无相互干扰,对个别毒株(JX08-45、Flury、SRV9)的中和活性表现出协同作用;三株单抗CR57、RV08和RV3A5单独应用或是三联配伍应用的暴露后保护率达100%,与HRIG单独免疫相比较具有更优秀的动物保护活性;在与疫苗联合应用方面重组人源单抗与HRIG在暴露后预防的效果相仿,均可达到100%的保护率,所以重组人源单抗具有替代HRIG应用于狂犬病暴露后预防与保护的潜力,为我国具有自主知识产权的狂犬单抗鸡尾酒制剂的研发打下基础。

To evaluate the neutralizing potency and spectrum of three recombinant human mAbs CR57（Ⅰ）,RV08（Ⅱ）,RV3A5（Ⅲ）and the triple combination cocktail against antigenic site Ⅰ,Ⅱ and Ⅲ on rabies virus glycoprotein,a standard fluorescent antibody virus neutralization test（FAVN）on several RV vaccine strains,fixed strains,and street strains of total 11 trains was performed by incubation of RV with varying concentrations of antibody followed by incubation with BHK-21 cells.To investigate whether the antibodies display neutralizing activity against a lethal RV infection in vivo,we performed a Syrian hamster study by infecting with 50LD50/100μl of CVS-11 strain intramuscularly（i.m.）in the gastrocnemius muscle.Three recombinant human mAbs CR57（I）,RV08（II）,RV3A5（III）and the compatibility triple cocktail showed broad cross-neutralizing reactivity to all 11 RV strains.The cocktail composed of three mAbs CR57（Ⅰ）,RV08（Ⅱ）,RV3A5（Ⅲ）by neutralizing titers of 1∶1∶1has no less in neutralizing ability against these strains,indicating that no mutual interference between the three antibodies.The cocktail exhibited neutralizing synergistic activity against individual strains（JX08-45,Flury,SRV9）.The treatment with CR57,RV08,RV3A5 or the triple combination cocktail alone respectively provided better protection with a survival range of 100%against the lethal RV infection compared HRIG immunized alone.Combined immunization with the vaccine,recombinant mAbs protected hamsters with a survival rate of 100%equally as well as HRIG after exposure to a lethal RV infection.Our results provide more candidates eligible for use in a mAb cocktail aimed at replacing RIG for rabies post-exposure prophylaxis.