The virtues of oxygenation: Low tissue oxygen adversely affects the killing of leishmania

Hypoxia contributes to the persistence of infections through altered immune responses. Studies examining skin O₂ changes at the site of a lesion are limited. The prevailing methods require the use of electrochemical O ₂ sensors or radiolabeled electrodes that utilize O₂ and may interfere with the precision at low O₂ levels. In this issue, Mahnke et al. (2014) demonstrate, using a novel fluorescence-based imaging technology, that low oxygen tension (pO₂) impairs NO-mediated anti-leishmanial immunity, leading to increased parasite burden. Replenishing tissue oxygen profoundly enhanced NO-mediated leishmanial killing, underscoring the need to accurately assess oxygenation in infected tissues as a novel strategy to challenge intracellular infection. The technology presented here may have clinical-translational potential in noninvasively assessing disease burden and response to treatment.