MELANOCYTE MOVEMENT IN-VITRO - ROLE OF MATRIX PROTEINS AND INTEGRIN RECEPTORS

During the repigmentation of vitiliginous skin, melanocytes migrate from the outer root sheath of the hair follicle into the depigmented skin. We hypothesize that this requires changes in the local microenvironment that are conducive to melanocyte migration. One important change in the micro-environment could be the localized production of matrix proteins. We have previously employed time-lapse photography to evaluate the effect of inflammatory mediators and cytokines on melanocyte movement. We have adapted this system to study the effect of matrix proteins on melanocyte movement in vitro. Type IV collagen significantly increases melanocyte migration, whereas laminin and fibronectin have no effect. Cell/matrix interactions are in part controlled by cell-surface integrins. Integrins have been demonstrated to be important in controlling the migration of many cell types. We demonstrate that melanocytes express cell-membrane alpha2, alpha3, and alpha5 integrins and that the enhanced melanocyte migration on type IV collagen is inhibited by specific function-blocking antibodies to integrins alpha2 and alpha3, but not to alpha5 integrins.