Salmonid B lymphocytes demonstrate organ dependent functional heterogeneity

The passive hemolytic plaque assay was used to examine the functional heterogeneity of antibody producing cells in salmonid immune organs. In this study, the antibody response to Vibrio anguillarum antigens was induced by the injection of a somatic antigen extract. This antigen was also coated onto sheep red blood cells (SRBC) for plaque forming cell (PFC) determination. Previous studies have demonstrated that this response is antibody dependent and antigen specific (Kaattari and Irwin, 1985). The present study was focused upon the heterogeneity of antibody producing cells that arise in the spleen, anterior and posterior kidney of immunized coho salmon (Oncorhynchus kisutch). The functional heterogeneity of lymphocytes was assessed by histogram analysis of the antigen inhibition profiles of the plaque forming responses. These analyses have revealed that the anterior kidney lymphocytes possess a much more restricted profile of antibody specificities than do lymphocytes from the posterior kidney or spleen. These data suggest that B cell repetoires differ among the immune organs of salmonids.