Rapid αβ T-cell responses orchestrate innate immunity in response to Staphylococcal enterotoxin A.

In the generation of a traditional immune response against invading pathogens, innate cells guide T cells by programming their differentiation. However, here we demonstrate that αβ T cells have an essential role in priming innate immunity in the lung after Staphylococcus aureus enterotoxin A (SEA) inhalation. We found that SEA induces waves of cellular activation, cytokine production, and migration into the lung tissue and airways. However, this innate response was completely inhibited in the absence of αβ T cells. Specifically, we found that interleukin (IL)-17A was required for the recruitment of neutrophils and monocytes into the lung. The cellular source of IL-17A was γδ T cells, which increased their IL-17A production following SEA but only in an αβ T-cell-dependent manner. Thus, rapid T-cell activation orchestrates innate immunity and may be a new point of therapeutic intervention for acute lung injury.