neutrophil inhibitory factor

Neutrophil inhibitory factor (NIF) is a recombinant 41-kDa glycoprotein originally discovered in the canine hookworm (*Ancylostoma caninum*). It acts as a highly selective antagonist of the leukocyte integrin Mac-1 (CD11b/CD18, αMβ2), specifically binding to the I-domain of the CD11b subunit. By blocking the interaction of Mac-1 with its endothelial and humoral ligands—including ICAM-1, fibrinogen, and complement iC3b—NIF potently inhibits neutrophil adhesion to vascular endothelial cells and subsequent transendothelial migration. This prevents neutrophil-mediated inflammatory tissue damage and vascular injury. Originally developed by Corvas International, NIF was licensed to Pfizer in 1995 and advanced into clinical development under the code name UK-279,276 (brand name Corleukin) for the treatment of acute ischemic stroke. However, development was discontinued in 2002 after the Phase II ASTIN trial failed to demonstrate clinical efficacy. Corvas was subsequently acquired by Dendreon in 2003.

Brand names

Corleukin

Other names

NIFrecombinant neutrophil inhibitory factorrNIF