IL-1α is a pro-inflammatory cytokine produced by activated monocytes, lymphocytes and epithelial cells (1). IL-1α is synthesized as an active precursor protein that appears to be cleaved by cytosolic proteases into its mature form (1,2). Often, precursor and mature forms of IL-1α are primarily retained intracellularly rather than constitutively secreted. (1,2). Signaling by IL-1α involves IL-1α binding to an IL-1 accessory protein (IL-1-AcP) and then the complex binds to IL-1RI (1,2). Signaling is through activation of MAP kinase and NFκB pathways (1,2). IL-1α also binds to an IL-RII that lacks an intracellular signaling domain and thereby serves as a high affinity decoy receptor. Inhibition of IL-1α activity is through IL-1R antagonist (IL-1Ra) that binds IL-1R1 but does not signal. IL-1α has been shown to be a key mediator of virus-induced inflammatory responses in mice (3).
