【作者】 李茂光； 俞永新； 刘欣玉； 徐宏山； 贾丽丽； 王志伟； 董关木；

【Author】 LI Mao-guang,YU Yong-xin,LIU Xin-yu,et al. (National Institute for the Control of Pharmaceutical and Biological Products,Beijing 100050,China)

【机构】 中国药品生物制品检定所；

【摘要】 目的研究SA14-14-2株流行性乙型脑炎(乙脑)减毒活疫苗(Live Attenuated Japanese Encephalitis Vaccine,JEV-L)和乙脑灭活疫苗(Inactivated Japanese Encephalitis Vaccine,JEV-I)在小鼠体内的免疫应答机制。方法将不同稀释度的SA14-14-2株JEV-L和SA14-14-2株JEV-I进行比较实验。以原倍、10-3、10-4、10-5稀释度JEV-L于0d一次,JEV-I于0、7d两次皮下免疫BALB/c小鼠,初次免疫后第14d处死,取脾脏,用酶联免疫斑点法(Enzyme-linked Immunospot,ELISPOT)检测脾淋巴细胞经JEV-L抗原刺激后分泌干扰素(Interferon,IFN)-γ和白细胞介素(Interleukin,IL)-2的水平,同时分离血清,混合后检测乙脑特异性IgG1、IgG2a和中和抗体水平。另一组相同免疫的小鼠于免疫后14d以P3毒株进行腹腔攻击,观察疫苗保护效果。结果与SA14-14-2株JEV-I相比,JEV-L免疫小鼠可产生更多数量的IFN-γ斑点形成细胞(Spot Forming Cell,SFC)和IL-2SFC,原倍JEV-L可同时诱导IgG2a和IgG1,而JEV-I免疫小鼠后只产生极少量的IFN-γSFC和IL-2SFC,并只能诱导IgG1抗体。JEV-L保护效果优于JEV-I,其稀释至10-3和10-4时中和抗体呈较低水平,但细胞免疫水平较强,并可保护90%和50%的小鼠免受致死剂量乙脑病毒的攻击。结论 SA14-14-2株JEV-L能同时诱导细胞免疫和体液免疫反应,两者均在保护小鼠免受致死剂量乙脑病毒攻击中发挥重要作用。而JEV-I仅诱导产生体液免疫反应,保护效果较JEV-L差。更多还原

【Abstract】 Objective To study the immune mechanism induced by live attenuated SA14-14-2 Japanese encephalitis vaccine and inactivated Japanese encephalitis vaccine in mice. Methods Live attenuated SA14-14-2 Japanese encephalitis vaccine of different dilutions were subcutaneously injected to BALB/c mice once at 0 day, and inactivated Japanese encephalitis vaccine were subcutaneously injected to BALB/c mice twice at 0 and 7days. Fourteen days after the first immunization, mice were sacrificed, and the spleens were removed aseptically for detection of IFN-γ and IL-2 spot forming cell (SFC) by ELISPOT assay. Serum samples were collected to detect the specific IgG2a and IgG1 antibody and neutralizing antibody. Another group of immunized mice were challenged by Japanese encephalitis virus P3 strain intraperitoneally to evaluate the protective efficacy at the fourteenth day after the first immunization. Results Mice immunized with the live attenuated SA14-14-2 Japanese encephalitis vaccine produced more IFN-γ SFC and IL-2 SFC than the inactivated Japanese encephalitis vaccine. IgG2a and IgG1 antibody could be induced at the same time by immunization with undiluted live attenuated Japanese encephalitis vaccine, while the inactivated Japanese encephalitis vaccine only induced the IgG1 antibody. The live attenuated Japanese encephalitis vaccine had a better protection than the inactivated Japanese encephalitis vaccine. The results indicated that 90% or 50% of mice with a low level of neutralizing antibody (1:10) but higher cellular immune level after immunization with 10-3 or 10-4 dilution of live attenuated Japanese encephalitis vaccine could survive against the challenge with a lethal dose of Japanese encephalitis virus. Conclusion Live attenuated SA14-14-2 Japanese encephalitis vaccine could induce both humoral and cellular immune response, which are all important factors to protect against the challenge with a lethal dose of Japanese encephalitis virus. However, the inactivated Japanese encephalitis vaccine could only induce humoral immune response and lower protective effect.更多还原