The immunodominant CD8+ T cell epitope region of Theiler's virus in resistant C57BL/6 mice is critical for anti-viral immune responses, viral persistence, and binding to the host cells

• Published in: Virology (New York, N.Y.) N.Y.), 2007-03, Vol.360 (1), p.159-171
• Main Authors: Myoung, Jinjong, Hou, Wanqiu, Kang, Bongsu, Lyman, Michael A, Kang, Jeong-Ah, Kim, Byung S
• Format: Article
• Language: English
• Subjects: Animals; Brain - immunology; Brain - virology; Capsid Proteins - immunology; CD4-Positive T-Lymphocytes - immunology; CD8+ T cells; CD8-Positive T-Lymphocytes - immunology; Cell Line; Cells, Cultured; CNS; Disease Models, Animal; Epitope; Epitopes, T-Lymphocyte - genetics; Epitopes, T-Lymphocyte - immunology; Female; H-2 Antigens - immunology; Histocompatibility Antigen H-2D; Immunodominant Epitopes - immunology; Infectious Disease; Lymphocyte Activation; Macrophages - virology; Mice; Mice, Inbred C57BL; Multiple Sclerosis - etiology; Mutant viruses; Mutation; Spinal Cord - immunology; Spinal Cord - virology; Theilovirus - physiology; TMEV; Virus Replication
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2006.09.045

Abstract Theiler's virus infection induces an immune-mediated demyelinating disease, providing a relevant animal model of human multiple sclerosis. VP2121–130 -specific CD8+ T cells in resistant H-2b mice account for the majority of CNS-infiltrating CD8+ T cells. To further study the role of the CD8+ T cells, we generated a panel of mutant viruses substituted with L, G, or T at the anchor residue (M130) of the VP2121–130 epitope. M130L virus (M130L-V) with a substitution of M with L displayed similar properties as wild-type virus (WT-V). However, M130G-V and M130T-V could not establish a persistent infection in the CNS. The level of both virus-specific CD8+ and CD4+ T cell responses is significantly reduced in mice infected with these variant viruses. While all mutant and wild-type viruses replicate comparably in BHK cells, replication of M130G-V and M130T-V in macrophages was significantly lower compared to those infected with WT-V and M130L-V. Interestingly, these mutant viruses deficient in replication in primary mouse cells showed drastically reduced binding ability to the cells. These results suggest that the anchor residue of the predominant CD8+ T cell epitope of TMEV in resistant mice is critical for the virus to infect target cells and this deficiency may result in poor viral persistence leading to correspondingly low T cell responses in the periphery and CNS. Thus, selection of the cellular binding region of the virus as the predominant epitope for CD8+ T cells in resistant mice may provide a distinct advantage in controlling viral persistence by preventing escape mutations.