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 activation 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, indicating that they were present in large detergent-resistant complexes. In contrast, the majority of the total cellular CD63, CD11 and CD18, which are largely intracellular, was not present in complexes. The data suggest that intracellular CD11, CD18 and CD63 are not in detergent-resistant complexes, but enter such complexes following translocation to the cell surface. (C) 2000 Federation of European Biochemical Societies.