Infection Protection During Inflammation

 

During microbial infection, neutrophils generate microbicidal agents through the release of myeloperoxidase (MPO). Eiserich et al. (p. 2391) report that MPO's actions during inflammation extend beyond generating antimicrobial oxidizing species. MPO permeates the mammalian vasculature and alters blood vessel function during acute inflammation by catabolizing nitric oxide (NO). NO is an endothelial-derived blood vessel relaxant that is produced in response to endotoxin. By reducing NO availability, MPO impairs vascular changes produced by infection. This finding may explain the increased susceptibility of humans deficient in MPO to infection.