Fibronectin increases the motility, phagocytosis and NBT (nitroblue tetrazolium)-reduction of granulocytes.

Neutrophilic granulocytes preincubated in vitro with human plasma fibronectin (0-1.25 mg/ml) for 30 minutes showed increased spontaneous and chemotactic migration, increased uptake of fluorescein labelled yeast particles as well as higher NBT-reduction both with and without E. coli stimulation. These effects on the granulocyte functions were found to be mainly dose dependent. In control experiments, no significant effects were noted when fibronectin was replaced by human serum albumin in the same concentration range.