S100A9 mediates neutrophil adhesion to fibronectin through activation of beta2 integrins.
Neutrophil migration from the blood to inflammatory sites follows a cascade of events, in which adhesion to endothelial cells and extracellular matrix proteins is essential. S100A8, S100A9, and S100A12 are small abundant proteins found in human neutrophil cytosol and presumed to be involved in leukocyte migration. Here we investigated the S100 proteins' activities in neutrophil tissue migration by evaluating their effects on neutrophil adhesion to certain extracellular matrix proteins. S100A9 induced adhesion only to fibronectin and was the only S100 protein that stimulated neutrophil adhesion to this extracellular matrix protein. Experiments with blocking antibodies revealed that neither beta1 nor beta3 integrins were strongly involved in neutrophil adhesion to fibronectin, contrary to what the literature predicted. In contrast, neutrophil adhesion to fibronectin was completely inhibited by anti-beta2 integrins, suggesting that S100A9-induced specific activation of beta2 integrin is essential to neutrophil adhesion.
Anceriz
Nadia
N
Infectious Diseases Research Center, Laval University Hospital Center, Quebec, Canada G1V 4G2.
Vandal
Karen
K
Tessier
Philippe A
PA
D018821:CD18 Antigens / Q000378:metabolism*; D040502:Calgranulin B / Q000494:pharmacology / Q000502:physiology*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D018375:Neutrophil Activation / Q000187:drug effects / Q000502:physiology*; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*
D018821:CD18 Antigens; D040502:Calgranulin B; D005353:Fibronectins