Beauverger P, Cardoso A I, Daviet L, Buckland R, Wild T F
INSERM Unit 404 "Immunity and Vaccination," Institut Pasteur de Lyon, France.
Virology. 1996 May 1;219(1):133-9. doi: 10.1006/viro.1996.0230.
In Balb/c (H-2d) mice, the nucleoprotein (NP) of measles virus (MV) induces a MHC class I restricted-CTL response to a single 9-amino-acid epitope (aa 281--289). This L(d)-restricted epitope is also present in the NP of the closely related canine distemper virus (CDV). To investigate whether this epitope is immunologically effective when it is present within the primary sequence of a nonviral protein, we have incorporated the 281--289 motif into the human CD36 protein. When cells are infected with vaccinia virus (VV) recombinants expressing this protein, CD36NP, the MV epitope is correctly processed and the cells are lysed by MVNP-specific CTLs. In vivo, VV-CD36NP induced CTLs which protected mice from a lethal dose of CDV, but did not block virus replication. The MVNP contains four other potential L(d)-restricted motifs. To investigate if these could be utilized in the absence of the dominant epitope, a mutant NP was produced in which one of the anchor residues in the aa 281--289 motif was mutated. Cells infected with a VV recombinant expressing this protein (VV-NP F289S) were only poorly lysed by MVNP-specific CTLs. Similarly, immunization of Balb/c mice with VV-NP F289S induced a lower level of CTL activity compared to the VV-NP, but the activity was now directed to three other epitopes. When mice were vaccinated with VV-NP F289S they were only partially protected from a lethal CDV challenge. The significance of these results for MV vaccine development is discussed.
在Balb/c（H-2d）小鼠中，麻疹病毒（MV）的核蛋白（NP）可诱导针对单个9氨基酸表位（氨基酸281 - 289）的MHC I类限制性CTL反应。这种L(d)限制性表位也存在于密切相关的犬瘟热病毒（CDV）的NP中。为了研究当该表位存在于非病毒蛋白的一级序列中时是否具有免疫效力，我们将281 - 289基序整合到人类CD36蛋白中。当细胞被表达该蛋白（CD36NP）的痘苗病毒（VV）重组体感染时，MV表位被正确加工，并且细胞被MVNP特异性CTL裂解。在体内，VV-CD36NP诱导的CTL可保护小鼠免受致死剂量的CDV感染，但不能阻止病毒复制。MVNP还包含其他四个潜在的L(d)限制性基序。为了研究在不存在显性表位的情况下这些基序是否可用，我们产生了一种突变NP，其中281 - 289基序中的一个锚定残基发生了突变。被表达该蛋白的VV重组体（VV-NP F289S）感染的细胞仅被MVNP特异性CTL微弱裂解。同样，用VV-NP F289S免疫Balb/c小鼠诱导的CTL活性水平低于VV-NP，但该活性现在针对其他三个表位。当用VV-NP F289S给小鼠接种疫苗时，它们仅部分受到保护，免受致死性CDV攻击。本文讨论了这些结果对MV疫苗开发的意义。
