[61] using MBP(79-87) TCR-tg mice [66] . Cytometric phenotyping, in vitro CD8 + T cell killing assays, and adoptive transfer experiments were used to track the expansion and killing capacity of Vα8Vβ8 MBP (79-87)-specific TCR and Vα8Vβ6-vaccinia virusspecific TCR. Infection of these tg mice with vaccinia virus induced autoimmune disease, thus demonstrating a virus triggering an autoimmune disease through dual TCR expressing T cells [61] . Although several tg TCR β-chains have been described on peripheral T cell [61, 67-70], there is no evidence that co-expression of dual TCRs leads to autoimmunity without the use of TCR-tg mice. As described above, current work in our laboratory has characterized TMEV-specific autoreactive CD8 + T cell clones derived from a wild-type animal, and these autoreactive TMEV-specific T cell clones express dual TCRs (manuscript in preparation). Importantly, we were able to induce CNS pathology in naïve SJL/J mice by adoptively transferring the TMEV-specific clones. Although further work is needed in order to identify the self-antigen that activates these CD8 + T cells, to our knowledge these results are the first demonstration of an autoimmune disease initiated by a dual expressing TCR characterized in the virus' natural host.