ACTINOBACILLUS-PLEUROPNEUMONIAE SEROTYPE-2 - EFFECTS ON THE INTERFERON-ALPHA PRODUCTION OF PORCINE LEUKOCYTES IN-VIVO AND IN-VITRO

Effects of a bacterial infection on the IFN-alpha production in vivo a nd in vitro were studied in eight specific pathogen free pigs experime ntally infected with Actinobacillus pleuropneumoniae. Clinically, the experimental infection was manifested as a febrile stage which lasted approximately one week and by signs of respiratory disease. The Aujesz ky's disease virus (ADV) induced IFN-alpha production, assessed in who le blood cultures, was increased for the infected pigs during the febr ile stage, Potentiating effects on the IFN-alpha production could be t ransferred to cultures of purified peripheral blood mononuclear cells with sera collected from the infected pigs during this period of time. Although the experimental infection with A. pleuropneumoniae did not induce any detectable amounts of IFN-alpha in serum or nasal secretion , both a phenol-extract and a heat-inactivated preparation of the bact eria induced low levels of IFN-alpha in cultures of purified PBMC, The interferogenic structures of the bacteria were not identified but the re were indications that the bacteria induced IFN-alpha production in the same cell type as ADV. (C) 1998 Elsevier Science Ltd. All rights r eserved.