表达轮状病毒VP4抗原的重组腺病毒对新生小鼠的被动免疫保护作用

目的探讨表达轮状病毒VP4抗原的重组腺病毒(Ad5/VP4)对新生小鼠的被动免疫保护作用。方法在293细胞上扩增表达猴轮状病毒SA11株VP4抗原的重组腺病毒并纯化。将轮状病毒抗体阴性的小鼠交配后的雌性小鼠,分别通过肌肉注射、滴鼻和口服免疫纯化后的重组腺病毒,生产后第7天和第8天,用轮状病毒SA11(1·0×106PFU)口服攻击乳鼠2次,观察出现腹泻症状的乳鼠的比例,并用ELISA检测母鼠的血清以及乳鼠胃囊乳块中的轮状病毒特异性抗体。同时以含有部分E1区基因的腺病毒5型载体(Ad5)作为对照。结果经3种不同途径免疫母鼠后,在血清和乳汁中均能检测到轮状病毒VP4特异性抗体。经滴鼻免疫的母鼠喂养的乳鼠,经攻击后保护率为100%(11/11);经肌肉注射免疫的母鼠喂养的乳鼠,经攻击后保护率为30%(3/10);经口服免疫的母鼠喂养的乳鼠,经轮状病毒攻击后保护率为80%(8/10)。对照组的小鼠全部出现了腹泻症状。结论表达轮状病毒VP4抗原的重组腺病毒经滴鼻免疫母鼠后,能在乳汁中产生特异性的IgA和IgG抗体,并能保护新生小鼠对抗轮状病毒的攻击,保护率达100%。

Passive Immune Protection of Neonatal Mice with Recombinant Adenovirus Expressing Rotavirus VP4 Antigen

Objective To explore the passive immune protection of recombinant adenovirus(Ad5/VP4)expressing rotavirus VP4 antigen in neonatal mice.Methods Recombinant adenovirus Ad5/VP4 was constructed by homologous recombination,proliferated in 293 cells and purified.The rotavirus antibody-negative female mice 3 d after mating with rotavirus antibody-negative male mice were divided into three test groups and inoculated with the purified Ad5/VP4 by intramuscular,intranasal and oral routes respectively,using adenovirus type 5 genome(Ad5)containing partial E1 gene as control.The neonatal mice were challenged twice with rotavirus SA11 by oral route on days 7 and 8 after birth respectively,each at a dosage of 1.0×10~6 PFU.Observe the diarrhea in neonatal mice and determine the specific antibody against rotavirus in sera of female mice and milk plug of neonatal mice by ELISA.Results After immunization by three routes,the specific antibodies against rotavirus were found in both sera of female mice and milk plug of neonatal mice.The protective rates of neonatal mice from the mothers immunized by intranasal,intramuscular and oral routes were 100%,30% and 80% respectively.However,diarrhea were observed in all the neonatal mice in control groups.Conclusion The recombinant adenovirus Ad5/VP4 expressing rotavirus VP4 antigen induced specific IgA and IgG in milk and showed a protective rate of 100% to the neonatal mice challenged with rotavirus.