Lysophosphatidic acids: III. Enhancement of neutrophil chemotaxis.

1-Palmitoyl-lysophosphatidic acid (LPA) was studied for its influence on the chemotaxis and ultrastructure of human neutrophils. By itself, LPA had no effect on the indices of chemotaxis or random migration of neutrophils. However, LPA on either the cellular or attractant side of Boyden chambers significantly enhanced the chemotactic responses of neutrophils to suboptimal concentrations of formyl-methionyl-phenylalanine. The enhancement of chemotaxis was achieved with concentrations of LPA (120-240 microM) that had no effect alone on neutrophil ultrastructure. The results, taken together with recent advances in knowledge of the role of the phosphatidylinositol turnover response in mediating effects of stimulating agents on cells, may provide a novel concept for understanding neutrophil chemotaxis.