Purification of surface-exposed integral outer membrane proteins of Actinobacillus pleuropneumoniae and their role in opsonophagocytosis.
Previously identified 39-, 50-, and 76-kd integral outer membrane proteins (IOMP) of Actinobacillus pleuropneumoniae, a respiratory tract pathogen, were separated by electroelution of sodium dodecyl sulfate-polyacrylamide gel electrophoresis-obtained fragments and their role in opsonophagocytosis by porcine leukocytes was investigated by flow cytometry of fluorescein-labeled A pleuropneumoniae. Using specific antisera, immunoblot analysis indicated that the 3 proteins were antigenically distinct. Antibodies against each IOMP have an important role as opsonins for phagocytosis by porcine leukocytes. The effect of using a combination of all 3 of the specific antisera was minimal. Antiserum absorbed against intact A pleuropneumoniae and Escherichia coli organisms indicated that the antibodies to the 39-, 50-, and 76-kd IOMP were specific for A pleuropneumoniae antigens. Nonheat-treated antiserum did not increase phagocytosis, compared with heat-inactivated antiserum, indicating that complement may not have a major role in opsonization of A pleuropneumoniae.
Thwaits
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Department of Animal Science, College of Biology and Agriculture, Brigham Young University, Provo, UT 84602.
Kadis
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D016977:Actinobacillus pleuropneumoniae / Q000276:immunology* / Q000302:isolation & purification; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D009895:Opsonin Proteins / Q000276:immunology; D010587:Phagocytosis / Q000276:immunology*; D013552:Swine
D001425:Bacterial Outer Membrane Proteins; D009895:Opsonin Proteins