Borna disease virus nucleoprotein (p40) is a major target for CD8(+)-T-cell-mediated immune response

Experimental infection of rats with Borna disease virus (BDV) and natural B DV infection of horses and sheep leads to a virus-induced T-cell-mediated i mmunopathology in the central nervous system. Earlier work revealed the imp ortance of the BDV-specific T-cell response and of CD8(+) effector cells in particular in the destruction of virus-infected cells. Evidence was also p resented that this major histocompatibility complex class I-restricted lysi s detected in vitro might play a functional role in the immunopathogenesis of Borna disease. The present study employed different vaccinia virus recom binants expressing single BDV-specific proteins to investigate the specific ity of the cytolytic CD8(+)-T-cell response, revealing a major epitope on t he BDV nucleoprotein p40. In contrast, no direct evidence in favor of the p resence of in vivo relevant cytotoxic T-lymphocyte epitopes on other BDV-sp ecific proteins was found.