LOSS OF L-SELECTIN (CD62L) ON HUMAN NEUTROPHILS FOLLOWING EXUDATION IN-VIVO

L-selectin, an adhesion molecule expressed on the surface of periphera l blood neutrophils, mediates the rolling of neutrophils along vascula r endothelium, Stimulation of neutrophils in vitro causes decreased ex pression of L-selectin on the surface of neutrophils due to shedding, In this study, we have demonstrated that human exudative neutrophils i solated from both skin lesions and from pus exhibit little expression of L-selectin, Although a dramatic accumulation of exudative neutrophi ls is observed in the skin lesions within 24 hr, there is no accompany ing increase in soluble L-selectin. In addition, the levels of soluble L-selectin in the extracellular tissue fluid (97.2 +/- 12,7 mu g/ml, n = 8) are only 20% of that observed in peripheral plasma (482.4 +/- 3 5.9 mu g/ml). These data suggest that shedding of L-selectin from the surface of neutrophils occurs in the peripheral circulation as a prelu de to diapedesis of neutrophils into peripheral tissues. (C) 1995 Acad emic Press, Inc.