During an inflammatory response, neutrophils move through the basement membrane and may interact with the abundant basement glycoprotein, laminin. Neutrophils contain a variety of proteolytic enzymes which specifically degrade the laminin A and B chains into smaller fragments. This study was undertaken to determine whether intact laminin or ten synthetic peptides corresponding to various regions of the laminin A and B1 chains stimulate human neutrophil chemotaxis and activated random migration (chemokinesis). Peptides F-9, F-11, F-12, and F-13 were derived from the laminin B1 chain cross-region, while six peptides were derived from the laminin A chain: peptide TG-1 from the amino terminus top globule; peptides GD-1, GD-3, GD-6, and GD-7 from the carboxy terminus globular domain; and peptide AG-1 from above the carboxy terminus globular domain. Laminin and the peptides were evaluated over a concentration range of 1-200 ug/mL in the motility assays. Only four of the peptides, F-12, TG-1, GD-6 and GD-1, stimulated PMN chemokinetic migration. Laminin and the other peptides failed to stimulate human PMN migration. In contrast, laminin stimulated rabbit peripheral blood PMN chemokinesis. These results demonstrate a species difference in human and rabbit PMN motility responses to laminin. Three peptides from the laminin A chain, TG-1, GD-6, and GD-1, and one peptide from the B1 chain, F-12, stimulate human PMN chemokinetic migration. These results indicate that intact basement membrane laminin does not directly stimulate human blood neutrophil motility, however, selected laminin peptide sequences which may be generated during basement membrane degradation can stimulate human neutrophil motility.
