ANTIVIRAL CYTOTOXIC-CELLS IN THE CHANNEL CATFISH (ICTALURUS-PUNCTATUS)

Cytotoxic cells isolated from the head kidney and peripheral blood of the channel catfish appear to represent distinct subpopulations of eff ector cells, Previous studies showed that the former lyse xenogeneic n atural killer (NK) cell targets, whereas the latter preferentially lys e allogeneic cells. Here we extend these studies and present data sugg esting a third class of cytotoxic effecters responsible for killing vi rus-infected allogeneic and autologous cells, Peripheral blood leukocy tes (PBLs) freshly isolated from unimmunized catfish lyse uninfected a llogeneic target cells as well as virus-infected allogeneic and autolo gous cells, Cell depletion and unlabeled (''cold'') target inhibition studies discriminated between putative effector classes and supported the view that at least two populations of cytotoxic cells are present within peripheral blood leukocytes. One population lyses allogeneic ta rgets, whereas a second population kills channel catfish virus (CCV)-i nfected cells, In addition, inhibitor studies demonstrated that early virus gene products are sufficient to render infected cells susceptibl e to lysis, These results suggest that channel catfish possess distinc t populations of NK-like, PBL-derived cytotoxic cells capable of lysin g allogeneic and virus-infected target cells. Copyright (C) 1996 Elsev ier Science Ltd.