P-SELECTIN (CD62) BINDS TO SUBPOPULATIONS OF HUMAN-MEMORY LYMPHOCYTES-T AND NATURAL-KILLER-CELLS

P-selectin (CD62) is a Ca2+-dependent lectin expressed on activated platelets and endothelium. Although P-selectin is known to function as a receptor for myeloid cells, previous studies indicated that P-selectin also bound to a subset of lymphocytes. Using a multi-color immunofluorescence assay we found that purified P-selectin bound to 12.2 ± 4.1 % of peripheral blood lymphocytes and that P-selectin could mediate adhesion of activated platelets to lymphocytes. A subpopulation of CD4+, CD8+, and CD16+ lymphocytes bound P-selectin. There was a marked preference for P-selectin binding to memory cells (CD45RO+) in both the CD4+ and CD8+ populations. Binding to all cell types was Ca2+-dependent and blocked by pretreatment of the cells with sialidase. These data suggest that P-selectin may play a role in the recruitment of specific lymphocyte populations to sites of inflammation. © 1992 Academic Press, Inc.