Intratracheal instillation of neutrophils rescues bacterial overgrowth initiated by trauma damage-associated molecular patterns.

Background: Nosocomial pneumonias are common in trauma patients and so interventions to prevent and treat nosocomial pneumonia may improve outcomes. Our prior work strongly suggests that tissue injury predisposes to infections like nosocomial pneumonia because mitochondrial debris originating from injured cells contains damage-associated molecular patterns that can reduce neutrophil (PMN) migration into the airway and diminish PMN function in response to bacterial inoculation of the airway. This suggested that putting exogenous "normal" PMN into the airway might be beneficial.