SPECIFIC IMMUNOGLOBULINS IN SERUM FROM ATLANTIC SALMON, SALMO-SALAR L, IMMUNIZED WITH VIBRIO-SALMONICIDA AND INFECTIOUS PANCREATIC NECROSIS VIRUS

Abstract. Atlantic salmon, Salmo salar L., responded to intraperitoneal injection of formalin killed Vibrio salmonicida or live infectious pancreatic necrosis virus (ipnv) by producing specific antibodies. The antibody titre varied significantly within the group tested. Western blot analysis demonstrated that high‐titre antisera recognized two major bacterial antigens with molecular weights of 12–15 kD and 22–27 kD. In addition, a few narrow bands with higher molecular weights were observed. An antiserum raised against IPNV recognised two major antigens corresponding to the structural proteins of the virus. Elisa and Western blot analysis showed that the immune serum raised against Vibrio salmonicida reacted slightly with Vibrio anguillarum, whereas no reaction to Yersinia ruckeri or Aeromonas salmonicida was detected. Indirect elisa and an elisa competition assay revealed that the immune serum raised against the N1 serotype was specific for this serotype of ipnv. The results demonstrate that Atlantic salmon has a humoral immune system capable of producing antibodies which discriminate between related bacterial antigens and between different serotypes of a virus. Copyright © 1990, Wiley Blackwell. All rights reserved