INTERACTION OF FIBRONECTIN (FN) CELL-BINDING FRAGMENTS AND INTERLEUKIN-8 (IL-8) IN REGULATING NEUTROPHIL CHEMOTAXIS

This study investigated the possible interaction of FN fragments in re gulating IL-8-mediated neutrophil chemotaxis in vitro using Neuroprobe microchambers. Human neutrophil suspensions were incubated with purif ied FN fragments or an RGD-containing peptide and allowed to migrate i n response to chemotactically active concentrations of human recombina nt IL-8. The 120-kD fragment of FN containing the RGD sequence or an R GD peptide (GRGDSP) inhibited IL-8-mediated neutrophil chemotaxis; how ever, these RGD peptides did not inhibit neutrophil chemotaxis in resp onse to other chemotactic agents. Furthermore, FN fragments not contai ning the RGD sequence had no effect on IL-8-mediated chemotaxis. These data suggest that directed migration of neutrophils in response to IL -8 is inhibited in the presence of cell-binding fragments of FN and ma y represent a local mechanism for terminating neutrophil migration at areas Of tissue injury. (C) 1994 academic Press, Inc.