CD63 associates with CD11/CD18 in large detergent-resistant complexes after translocation to the cell surface in human neutrophils

CD63 antibody binding to the neutrophil surface triggers a transient activa tion signal that regulates the adhesive activity and surface expression of CD11/CD18. Gel permeation chromatography demonstrated that all of the cell surface CD11/CD18 associated with CD63 eluted in the void volume, indicatin g that they were present in large detergent-resistant complexes. In contras t, the majority of the total cellular CD63, CD11 and CD18, which are largel y intracellular, was not present in complexes. The data suggest that intrac ellular CD11, CD18 and CD63 are not in detergent-resistant complexes, but e nter such complexes following translocation to the cell surface. (C) 2000 F ederation of European Biochemical Societies.