Suppression of the humoral immune response of Atlantic salmon, Salmo salar L. by the 64 kDa serine protease of Aeromonas salmonicida.
Bacteria-free supernatants of broth cultures of Aeromonas salmonicida inhibited the humoral immune response, but not the cell-mediated immune response, of Atlantic salmon to bacteriophage MS2. The immunosuppressive factor was the 64 kDa serine protease secreted by A. salmonicida. The suppressive activity was not due to degradation of epitopes of MS2, and although serine protease degraded the heavy chain of salmon IgM in vitro there was no evidence for significant degradation in vivo. The principal lethal toxin of A. salmonicida, the glycerophospholipid: cholesterol acyltransferase did not inhibit the immune response of salmon.
Division of Infection and Immunity, University of Glasgow, Scotland.
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I
Hussain
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Mackie
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D
Cox
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R
Alderson
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Birkbeck
D000333:Aeromonas / Q000201:enzymology*; D000818:Animals; D000917:Antibody Formation; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D006388:Hemagglutinins / Q000302:isolation & purification; D006460:Hemolysin Proteins / Q000302:isolation & purification; D017909:Levivirus / Q000276:immunology; D020317:Salmo salar / Q000276:immunology* / Q000821:virology; D012697:Serine Endopeptidases / Q000378:metabolism*
D006388:Hemagglutinins; D006460:Hemolysin Proteins; D012697:Serine Endopeptidases