Alveolar macrophage dysfunction associated with viral pneumonitis.

Viral infections are known to predispose to bacterial infections of the lung. Studies on the virus-induced suppression of pulmonary bactericidal mechanisms have identified the defect with abnormalities in the alveolar macrophage phagocytic system. In the investigation presented herein, we have dissected some of the subcomponents of the phagocytic process and found virus-induced defects in phagocytic ingestion, phagosome-lysosome fusion, and intracellular killing.