CD59 (homologous restriction factor 20), a plasma membrane protein that protects against complement C5b-9 attack, in human atherosclerotic lesions

Blood cells express a cell membrane protein, termed homologous restriction factor 20 (HRF20) and identical to CD59, that can inhibit complement C5b-9 insertion into their membranes. In this report, we investigated by immunohistochemistry whether CD59 was present on cells in human atherosclerotic lesions since membranous C5b-9(m) has been found in lesions. Using a monoclonal anti-CD59 antibody, a cellular CD59 staining pattern was apparent in nearly all lesion specimens. CD59 stain co-localised with macrophage (CD14), T lymphocyte (CD7), endothelial cell (anti-factor VIII related antigen) and smooth muscle cell cytoskeletal-specific antigens (anti-alpha actin and muscle myosin). Endothelial …