Chemotaxis of Human Polymorphonuclear Leukocytes under Agarose: Lack of Requirement for Media Protein and Differential Effects of Buffer and Agarose Type on Locomotion

Abstract

Migration and chemotaxis of human polymorphonuclear leukocytes (PMN) under agarose was studied in the presence and absence of various proteins. Contrary to previous reports, chemotaxis could be elicited in a protein-free medium using both complement-derived factors and fMet - Leu - Phe. Cell movement was critically dependent on the choice of agarose and buffer system. Addition of human serum or albumin produced marked chemokinesis while gelatin had no effect. These results indicate that media protein is a methodological requirement of some in vitro test systems but not a physiological requisite for PMN chemotaxis. The described procedures provide a valuable control for studying protein effects on cell migration as well as a means of avoiding unwanted cell stimulation and inactivation of test substances by media protein. This should facilitate studying chemokinetic and chemotactic materials, helper factors, and pharmacological agents. Agarose types were found to differ in the occurrence of a concentration dependent inhibition of locomotion. This suggests that restriction of cell movement by agarose may influence migration of PMN with abnormalities possibly unrelated to locomotion (e.g., cell swelling and decreased deformability induced by pharmacological agents or disease). Conditions are described which should minimize or enhance detection of such phenomena.