BCG-CpG-DNA佐剂人用狂犬病疫苗(MRC-5细胞)在食蟹猴体内的免疫原性

Immunogenicity of BCG-CpG-DNA adjuvant rabies vaccine (MRC-5 cell)for human use in cynomolgus monkeys

目的 评价BCG-CpG-DNA佐剂人用狂犬病疫苗(MRC-5细胞)在食蟹猴体内的免疫原性。方法 将食蟹猴随机分为对照组、3针组及4针组,经后肢肌肉免疫,1.0 mL/剂。3针组及4针组均接种BCG-CpG-DNA佐剂人用狂犬病疫苗,3针组于0 d、7 d、21 d各接种1剂,4针组于0 d、3 d、7 d、14 d各接种1剂;对照组接种市售国产同类疫苗,于0 d注射2剂、7 d及21 d各1剂。初免前(0 d)及初免后7 d、14 d、28 d、35 d、49 d、63 d后肢隐静脉采血,分离血清及外周血淋巴细胞。快速荧光灶抑制实验(Rapid Fluorescent focus Inhibition Test, RFFIT)及酶联免疫斑点检测技术(Enzyme-linked Immunospot Assay, ELISPOT)分别检测血清中抗狂犬病病毒中和抗体水平和外周血淋巴细胞中细胞因子IFN-γ、IL-2的表达水平。结果 食蟹猴血清中和抗体水平于免疫前均呈阴性(抗体效价<0.5 IU/mL),3针组和对照组在初免后7~28 d呈上升趋势,于28 d达最高,4针组在14 d达最高;在初免后28 d,对照组、3针组中和抗体水平显著高于4针组;初免后35 d,3针组中和抗体水平显著高于4针组,其余时间点同时间各组间差异均无统计学意义(P均>0.05)。3针组及4针组外周血淋巴细胞中IL-2及IFN-γ水平在7~14 d呈上升趋势,于14 d达最高,且3针组IFN-γ水平显著高于对照组,其余时间点同时间各组间差异均无统计学意义。结论 BCG-CpG-DNA佐剂人用狂犬病疫苗(MRC-5细胞)具有良好的免疫原性,具有优化狂犬病免疫接种程序的应用价值。

To evaluate the immunogenicity of BCG-CpG-DNA-adjuvanted human rabies vaccine(MRC-5 cell)in cynomolgus monkeys,we randomly divided monkeys into a control group,three-dose group,and four-dose group.The three-dose and four-dose groups were vaccinated with BCG-CpG-DNA-adjuvanted human rabies vaccine for human use at 0,7,and 21,or at 0,3,7,and 14 days,respectively.The control group was vaccinated with a commercially available domestic vaccine with a 2-1-1 protocol.Serum samples were collected from all monkeys before(0 day)and after immunization,on days 7,14,28,35,49,and 63.RFFIT and ELISPOT were used to detect anti-rabies virus neutralizing antibodies and cytokines(IFN-γand IL-2).The anti-rabies virus neutralizing antibodies in all groups were negative before immunization.The three-dose and control groups showed an increasing trend from 7 to 28 days after primary immunization,and the highest level was reached on the 28th day;in contrast,the four-dose group showed a peak on the 14th day.On the 28th day,the neutralizing antibody levels in the control and three-dose groups were significantly higher than those in the four-dose group.On the 35th day after the initial immunization,the neutralizing antibodies in the three-dose group was significantly higher than those in the four-dose group.The levels of IL-2 and IFN-γin peripheral blood lymphocytes in the three-dose and four-dose groups tended to increase from 7 to 14 days and peaked on the 14th day;the level of IFN-γin the three-dose group was significantly higher than that in the control group on the 14th day.Otherwise,no significant differences in the levels of neutralizing antibodies and cytokines were observed among all groups at all other time points.Thus,BCG-CpG-DNA adjuvanted human rabies vaccine(MRC-5 cell)has excellent immunogenicity and application value for optimizing immunization procedures.