Altered cell signaling and mononuclear phagocyte deactivation during intracellular infection.

Given the critical antimicrobial properties of mononuclear phagocytes, an important concern in cell biology and immunology has been to understand how intracellular microbes are able to establish states of chronic infection within these cells. Recent studies indicate that mononuclear phagocytes become functionally deactivated during intracellular infection. Here, Neil Reiner considers the experimental evidence to indicate that this is a frequent event that may be accounted for by induced defects in the signaling pathways required to bring cells to an activated state.