Immune cell expression of GABAA receptors and the effects of diazepam on influenza infection

•Human alveolar macrophage expresses the α1 GABAA subunit.•Influenza induces dynamic changes in GABAA subunit expression.•Diazepam increases susceptibility to bacterial superinfection.•GABAA receptors may play a role in the endogenous antibacterial immune response.•GABAergic drugs, such as sedatives, may have important immune consequences.

Benzodiazepines increase vulnerability to infection through α1 subunit dependent Υ-amino-butyric-type-A (GABAA) signalling. Immune cell expression of GABAA receptors and the effect of diazepam on influenza infection was investigated. In patients with pneumonia, α1 GABAA subunits were expressed on alveolar macrophages and blood monocytes. In mice, influenza induced dynamic changes in immune cell GABAA subunit expression: α1 subunits decreased on alveolar macrophage, but increased on monocytes, CD4 + and CD8 + T cells. Following influenza viral infection, diazepam delayed weight loss on day 3 but later increased weight loss. Viral load was unaffected but increased bacterial superinfection was noted on day 10.