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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抗体,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。
Objective To study the effects of live attenuated Japanese encephalitis vaccine (JEV-L) and Inactivated Japanese Encephalitis Vaccine (JEV-I) on SA14-14-2 strain, Immune response mechanism in mice. Methods Different dilutions of JEV-L strain SA14-14-2 and JEV-I strain SA14-14-2 were compared. BALB / c mice were immunized subcutaneously with JEV-L at 10-3, 10-4, and 10-5 dilutions on day 0, and JEV-I at 0 and 7 days after sacrifice. The spleens , And the levels of Interferon (IFN) -γ and Interleukin (IL) -2 secreted by JEV-L antigen in splenic lymphocytes were detected by enzyme-linked immunospot (ELISPOT) At the same time, the serum was separated and mixed for detection of JE-specific IgG1, IgG2a and neutralizing antibody levels. Another group of mice immunized with the same immunized mice were intraperitoneally challenged with P3 strain 14 days after immunization to observe the protective effect of the vaccine. Results Compared with JEV-I of SA14-14-2 strain, JEV-L-immunized mice produced more quantities of IFN-γ spot-forming cells (SFC) and IL-2SFC, While IgG2a and IgG1 antibodies were induced, whereas JEV-I mice produced only minimal amounts of IFN-γSFC and IL-2SFC and only IgG1 antibodies. JEV-L is more potent than JEV-I in that it neutralizes antibodies to 10-3 and 10-4 dilutions at low levels, but has a high level of cellular immunity and protects 90% and 50% of mice from Lethal dose of JE virus attack. Conclusions SAE 14-14-2 strain JEV-L induces both cellular and humoral immune responses, both of which play an important role in protecting mice against lethal doses of JE virus challenge. JEV-I only induced humoral immune response, the protective effect is worse than JEV-L.