Deactivation of the Innate Cellular Immune Response Following Endotoxic and Surgical Injury

The innate cellular immune (iCMI) system provides for the rapid production of interferon-γ (IFNγ) by NK cells in response to microbial threats. In this review, we examine the cellular and cytokine mechanisms of innate cellular immunity as determined in murine endotoxemia. This will be contrasted to the subsequent suppression of these same responses present in the mouse model of endotoxin tolerance, which is characterized by profound deficiency in both IL-12 and IFNγ synthesis. Transient IFNγ deficiency due to altered iCMI function has also been described in trauma or burn patients and is termed “clinical immune paralysis.” If the common pathogenesis of these entities can be better understood, immune-based interventions might be identified for restoring iCMI function. In addition to the gain in basic immunologic insight, research on this subject may deliver future forms of prophylaxis against infection that do not rely on antibiotics and that will not promote antimicrobial resistance.