NIF Proteins and Enzymes

Neutrophil inhibitory factor (NIF) of the dog hookworm, Ancylostoma caninum, is a 41 kDa secreted glycoprotein that is thought to allow the hookworm to evade the innate immune defenses of the host. NIF interacts with the leukocyte integrin alpha M beta 2 (CD11b/CD18, also called Mac-1), blocking adhesion to ligands including ICAM-1/CD54, complement component C3b, and fibrinogen, and effectively inhibiting neutrophil adhesion to endothelium. In mammalian inflammatory lung injury models, administration of NIF prevented neutrophil-dependent vascular injury.