In vitro generation of viral-antigen dependent cytotoxic T-cells from ginbuna crucian carp, Carassius auratus langsdorfii

Little is known about antigen-specific T-cell responses to viruses in teleosts due to a lack of a suitable experimental system using inbred or clonal animals. In the present study we have successfully induced an in vitro generation of virus-specific cytotoxic T-cells (CTLs) from isogeneic ginbuna crucian carp. Responder cells (primarily lymphocytes) from crucian carp haematopoietic necrosis virus (CHNV)-infected fish were capable of proliferating after stimulation in vitro with CHNV-infected syngeneic stimulator cells (primarily lymphocytes and macrophages). The effector cells collected 8 and 12 days after the in vitro stimulation efficiently lysed CHNV-infected syngeneic cells, but not CHNV-infected allogeneic cells or different virus (EVA)-infected syngeneic cells. Furthermore, in situ hybridization analysis showed that some effector cells binding to a CHNV-infected target were TCRβ or CD8α positive. These results provide evidence that the teleost effector cells generated in vitro correspond to virus-specific CTL and they recognize virus-infected target cells in a similar manner of mammalian counterparts.