A Detailed Characterization of the Dysfunctional Immunity and Abnormal Myelopoiesis Induced by Severe Shock and Trauma in the Aged.

The elderly are particularly susceptible to trauma, and their outcomes are frequently dismal. Such patients often have complicated clinical courses and ultimately die of infection and sepsis. Recent research has revealed that although elderly subjects have increased baseline inflammation as compared with their younger counterparts, the elderly do not respond to severe infection or injury with an exaggerated inflammatory response.

Improved emergency myelopoiesis and survival in neonatal sepsis by caspase-1/11 ablation.

Over one million newborns die annually from sepsis with the highest mortality in premature and low-birthweight infants. The inflammasome plays a central role in the regulation of innate immunity and inflammation, and is presumed to be involved in protective immunity, in large part through the caspase-1-dependent activation of interleukin-1β (IL-1β) and IL-18. Studies in endotoxic shock, however, suggest that endogenous caspase-1 activity and the inflammasome contribute to mortality primarily by promoting excessive systemic inflammatory responses.

TRIF-dependent innate immune activation is critical for survival to neonatal gram-negative sepsis.

Current evidence suggests that neonatal immunity is functionally distinct from adults. Although TLR signaling through the adaptor protein, MyD88, has been shown to be critical for survival to sepsis in adults, little is known about the role of MyD88 or TRIF in neonatal sepsis. We demonstrate that TRIF(-/-) but not MyD88(-/-) neonates are highly susceptible to Escherichia coli peritonitis and bacteremia.

Delayed emergency myelopoiesis following polymicrobial sepsis in neonates.

Neonates have increased susceptibility to infection, which leads to increased mortality. Whether or not this as a result of implicit deficits in neonatal innate immune function or recapitulation of innate immune effector cell populations following infection is unknown. Here, we examine the process of emergency myelopoiesis whereby the host repopulates peripheral myeloid cells lost following the initial infectious insult.

Novel role for tumor-induced expansion of myeloid-derived cells in cancer cachexia.

Cancer progression is associated with inflammation, increased metabolic demand, infection, cachexia, and eventually death. Myeloid-derived suppressor cells (MDSCs) commonly expand during cancer and are associated with adaptive immune suppression and inflammatory metabolite production. We propose that cancer-induced cachexia is driven at least in part by the expansion of MDSCs.

Persistent inflammation, immunosuppression, and catabolism syndrome after severe blunt trauma.

Background: We recently proffered that a new syndrome persistent inflammation, immunosuppression, and catabolism syndrome (PICS) has replaced late multiple-organ failure as a predominant phenotype of chronic critical illness. Our goal was to validate this by determining whether severely injured trauma patients with complicated outcomes have evidence of PICS at the genomic level.

Methods: We performed a secondary analysis of the Inflammation and Host Response to Injury database of adults with severe blunt trauma.