Bianchi A T, Moonen-Leusen H W, van Milligen F J, Savelkoul H F, Zwart R J, Kimman T G
DLO Institute of Animal Science and Health, Department of Mammalian Virology and Immunology, Lelystad, The Netherlands.
Vaccine. 1998 Oct;16(16):1550-8. doi: 10.1016/s0264-410x(98)00044-9.
In this study we firstly established a vaccination/challenge model to study pseudorabies virus infection in mice. The mouse model was used to investigate the significance of CD4+ and CD8+ cells and of IFN gamma production in protective immunity. Functional depletion of CD4+ and CD8+ and IFN gamma was obtained in vivo by intraperitoneal injection of alginate-encapsulated anti-CD4, -CD8 or -IFN gamma producing hybridoma's before and at the moment of vaccination. The observed protective immunity was correlated with underlying immunologic responses such as PRV-specific DTH reactivity, lymphoproliferation and cytotoxicity. The significance of CD4+ and CD8+ cells and of IFN gamma production was also investigated for these immunological responses by the same in vivo depletion technique. The results demonstrated that protective vaccination of mice, that could be induced by immunization with 10(7) plaque forming units of the avirulent PRV mutant NIA3 TK-, was characterized by a typical anti-viral Th1 type immune response. A clear PRV-specific, CD4-dependent DTH reactivity and a classical CD8-dependent, MHC-restricted cytotoxicity was induced after protective immunization and the humoral immune response had a bias towards PRV-specific IgG2a formation. In vivo treatment with anti-CD8 and anti-IFN gamma demonstrated that the cytotoxic response and humoral IgG2a response, respectively, were strongly reduced, whereas protection against lethal challenge was unaffected. On the other hand anti-CD4 treatment reduced the induced protection so that 30% of the mice died after lethal challenge. The results of our study demonstrated that CD4+, DTH like effector cells are a crucial effector mechanism for protective immunity against PRV.
在本研究中，我们首先建立了一个疫苗接种/攻毒模型来研究小鼠伪狂犬病病毒感染。该小鼠模型用于研究CD4⁺和CD8⁺细胞以及IFN-γ产生在保护性免疫中的意义。在接种疫苗前及接种时，通过腹腔注射藻酸盐包封的抗CD4、抗CD8或抗IFN-γ产生杂交瘤，在体内实现CD4⁺、CD8⁺和IFN-γ的功能耗竭。观察到的保护性免疫与潜在的免疫反应相关，如PRV特异性迟发型超敏反应（DTH）、淋巴细胞增殖和细胞毒性。还通过相同的体内耗竭技术研究了CD4⁺和CD8⁺细胞以及IFN-γ产生对这些免疫反应的意义。结果表明，用10⁷个空斑形成单位的无毒PRV突变体NIA3 TK⁻免疫可诱导小鼠产生保护性疫苗接种，其特征为典型的抗病毒Th1型免疫反应。保护性免疫后诱导出明显的PRV特异性、CD4依赖性DTH反应性以及经典的CD8依赖性、MHC限制性细胞毒性，并且体液免疫反应倾向于PRV特异性IgG2a的形成。用抗CD8和抗IFN-γ进行体内治疗表明，细胞毒性反应和体液IgG2a反应分别强烈降低，而对致死性攻毒的保护作用不受影响。另一方面，抗CD4治疗降低了诱导的保护作用，以至于30%的小鼠在致死性攻毒后死亡。我们的研究结果表明，CD4⁺、类似DTH的效应细胞是针对PRV保护性免疫的关键效应机制。
