Phagocyte Impotence Caused by an Invasive Bacterial Adenylate Cyclase

For unknown reasons, humans infected with the bacterium Bordetella pertussis are exceptionally vulnerable to secondary infections. Bordetella species elaborate a soluble, heat-stable, and highly active adenylate cyclase. This enzyme is internalized by phagocytic cells and catalyzes the unregulated formation of adenosine 3′,5′-monophosphate (cyclic AMP), thereby disrupting normal cellular function. This unusual phenomenon may explain Bordetella -induced aphylaxis and may prove to be useful for investigating a variety of cyclic AMP-governed processes.