Polyclonal activation of salmonid B lymphocytes.

The process of in vitro polyclonal activation of coho salmon (Oncorhynchus kisutch) lymphocytes was examined with respect to the induction of mitogenesis, total immunoglobulin production, and the production of specific antibodies or plaque forming cells. These studies demonstrate that antigen specific stimulation of antibody production is not linked to mitogenic activity, or total immunoglobulin production, while the polyclonal activation of specific antibody production is closely linked to these functions. Stimulation of immunoglobulin production by phytohemagglutinin suggests that this mitogen may not be limited to T cell activation in salmonids or, alternatively, it may induce the production of lymphokines capable of polyclonally activating B cells. Further, fetal calf serum was found to cause production of large amounts of immunoglobulin in vitro without antigenic stimulation.