P-selectln is a Ca2+-dependent lectln that participates in leukocyte adhesion to vascular endothellum and platelets. Myeloid cells and a subset of T lymphocytes express carbohydrate llgands at the cell surface. Previously, we suggested that heat stable antigen (HSA/mouse CD24), an extensively glycosylated cell surface molecule on many mouse cells, is a llgand for P-selectin. Here we show that HSA mediates the binding of monocytic cells and neutrophlls to P-selectin. The monocytlc cell lines ESb-MP and J774, peritoneal exudate cells, and bone marrow neutrophils could bind to lipopolysaccharlde-activated bend3 endothelioma cells under rotation-induced shear forces and this binding was inhibited by mAb to P-selectln and HSA. Blocking was weak at room temperature but more efficient at 4°C when Integrln-mediated binding was decreased.
ناشر :Oxford Journals