PHYLOGENY OF LYMPHOCYTE HETEROGENEITY - CYTOTOXIC ACTIVITY OF CHANNEL CATFISH PERIPHERAL-BLOOD LEUKOCYTES DIRECTED AGAINST ALLOGENEIC TARGETS

Channel catfish peripheral blood contains leukocytes that function as cytotoxic effecters directed against a variety of long-term cultured allogeneic, but not xenogeneic, targets. These effector cells are probably distinct from macrophages, B cells, and nonspecific cytotoxic cells. The cytotoxic activity of these effector cells was inhibited with monoclonal antibody 1H5. Although this reagent appears to react with a catfish cell surface molecule akin to the integrin LFA-1 present on the surface of nearly all leukocytes, it does not clarify the question as to whether or not these effecters are related to T cells.