Characterization of Marek's disease herpesvirus-specific cytotoxic T lymphocytes in chickens inoculated with a non-oncogenic vaccine strain of MDV

Abstract

Previously we have reported that reticuloendotheliosis virus (REV)-transformed cell lines expressing Marek's disease virus (MDV) genes pp38, meq or gB were lysed by syngeneic MDV-specific splenocytes from major histocompatibility complex (MHC): B9B19 and MHC: B1B21 chickens. In contrast, REV-transformed cell lines expressing the MDV gene ICP4 were only lysed by syngeneic MDV-specific splenocytes from MHC: B21B21 chickens. In this study we report that this syngeneic cell-mediated immune response is induced by cytotoxic T lymphocytes (CTL). Splenocytes from MDV vaccine strain, SB-1 inoculated MHC:B19B19 and MHC:B21B21 chickens, depleted for CD4+, CD8+, TCRγδ+, TCRαβ1+ and/or TCRαβ2+ cells, were used as effector cells in chromium-release assays. Effector cells depleted of CD8+ or TCRαβ1+, but not TCRγδ+ or TCRαβ2+, markedly reduced the MDV-specific release. Depletion of CD4+ effector cells did not influence the specific release significantly. This is the first report on identification of virus-specific CD8+ CTL in chickens inoculated with a non-oncogenic vaccine strain of MDV.