TLR-induced activation of neutrophils promotes histamine production via a PI3 kinase dependent mechanism

► Histamine is upregulated during LPS-induced acute lung injury. ► Neutrophils release histamine upon activation by TLR agonists. ► Histidine decarboxylase is necessary for histamine production. ► LPS-induced histamine requires PI3 kinase. ► Histamine is not required for neutrophil granule integrity.