Effects of Sendai virus infection on function of cultured mouse alveolar macrophages

Cultured mouse alveolar macrophages supported the growth of Sendai virus (murine parainfluenza I virus), as measured by both a 10-fold increase in extracellular virus titers and development of viral antigens on most of the cells. Synthesis of virus continued for at least 1 month without cytopathic effects. Macrophage phagocytic activity for Candida, Staphylococcus epidermidis, and opsonized erythrocytes remained unaffected by the infection, and the ability of the cells to kill S. epidermidis and S. Aureus was also unchanged. The defects in alveolar macrophage function observed in Sendai-infected mouse lungs probably are not due to a direct effect of the virus on macrophage function.