Alteration of alveolar macrophage functions after aerosol infection with bovine herpesvirus type 1

Calves were aerosol challenged with bovine herpesvirus type I, and bronchoalveolar cells were subsequently retrieved by lavage from days 1 to 8 postinfection. Alveolar macrophages (AM), which were depleted of contaminating cells, were characterized with respect to phenotypic markers and functional activities. In most aspects, the changes suggested a stimulation of the AM. With variations in kinetics the percentage of AM expressing an MHC II antigen and Fc (immunoglobulin G)-mediated phagocytosis increased, as did the activity level of two ectoenzymes and the lysosomal hydrolase beta-glucoronidase. The generation of prostaglandin E2 by the AM also rose significantly. However, selective suppression of cellular cytotoxicity and interleukin-1 generation was observed. These findings may have important implications for understanding the events involved in the virus-bacterial interaction in respiratory diseases.