Objective To investigate the cellular and humoral immune responses and protective effect induced by co-immunization with two multi-epitope combinant antigens. Methods Mice were co-im-munized with the muhi-epitope HCV-T and HCV-E1 antigens three times. Sera antibodies IgG, IgG1 and IgG2a were tested by ELISA. Spleens from BALB/c mice immunized were removed 10 days after the last im-munization. CTL activity was assessed using LDH cytotoxicity assay kit. IFN-γ- and IL-4-secreting cells were quantified using ELISPOT kit. Two weeks after the final immunization, the mice were challenged sub-cutaneously(s, c. ) at the back with 106 SP2/0-NS3 cells, and protective effect was observed. For therapy, 106 SP2/0-NS3 cells were implanted into the back of BALB/c mice. Seven days later, mice were immuniza-tion three times. Therapy effect was observed. Results Co-immunization with HCV-T and HCV-E1 induced high tiers of HCV-El-specific IgG, IgG1 and IgG2a antibodies, and high level of CTL activity. Synergistic effect in frequencies of both specific IFN-γ-secreting cells and IL-4-secreting cells was observed in mice co-immunized. Prophylactic as well as therapeutic administration of mT + mE1 in mice led to protecting mice against SP2/0-NS3 cells. These results suggested that mT + mE1 was potential as a prophylactic as well as therapeutic HCV vaccine. Conclusion Co-immunization with HCV-T + HCV-EI induced protective humor-al and cellular immune response. HCV-T + HCV-E1 was potential as a recombinant HCV vaccine.%目的 研究两个丙型肝炎病毒(HCV)多表位重组抗原联合免疫后诱导的细胞免疫和体液免疫应答,以及对小鼠的保护作用.方法 用两个多表位抗原HCV-T和HCV-E1联合免疫BALB/c小鼠3次,ELISA检测血清中抗体IgG、IgG1和IgG2a滴度;最后一次免疫后10 d杀死一半小鼠,取脾细胞,用乳酸脱氢酶(LDH)释放法检测细胞毒性T淋巴细胞(CTL)活性;ELISPOT法检测分泌IFN-γ和IL4的细胞;最后一次免疫后2周,在免疫小鼠的背部皮下注射106个SP2/0-NS3细胞,考察联合免疫对小鼠的保护作用;另取BALB/c小鼠,先在背部皮下注射106个SP2/0-NS3细胞,7 d后开始联合免疫,免疫3次,考察免疫治疗作用.结果 用HCV-T+HCV-E1联合免疫诱导了高滴度的HCV-E1特异性的IgG、IgG1和IgG2a抗体以及高水平的CTL活性;与单独免疫相比,联合免疫产生的分泌IFN-γ和IL-4的细胞数量有协同作用;而且联合免疫能有效预防和治疗SP2/0-NS3对小鼠的攻击.结论 HCV-T+HCV-E1联合免疫诱导了保护性的体液免疫和细胞免疫应答,有望进一步开发为一种有效的重组HCV疫苗.
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