Macrophage response and lung injury from thoacic RT is enhanced by subsequent influenza infection II

RILI is enhanced by subsequent influenza A virus (IAV) infection, leading us to hypothesize that the irradiated lung microenvironment alters macrophage dynamics and functioning following IAV. CD45+ immune cells were isolated from the lungs of C57Bl/6J mice that had been exposed to RT, IAV, RT plus IAV, or vehicle control.

IAV inoculation occurred 1 week post RT and lungs were harvested 1 following IAV inoculation. Whereas RT alone did not increase MDMs, they were increased in the flu conditions and were the most elevated from combined exposure to both RT and IAV. The proportions of immature MDMs were also greater after RT plus IAV when compared to IAV alone.