title: Localization of S protein and its relationship to the membrane attack complex of complement in renal tissue.
abstract: The S protein (S) binds to the attack complex of complement (C5b-9) in plasma preventing cytolysis. Using immunofluorescence microscopy, the authors determined the distribution of S in human renal tissue and its relationship to C5b-9, immunoglobulins, C3, albumin, and fibronectin. They examined normal and diseased human kidney tissue from patients with several forms of glomerulonephritis, diabetic nephropathy, and arterionephrosclerosis. S and C5b-9 were found in all diseased tissues; their amounts and distribution directly correlated with severity and location of injury. S and C5b-9 were colocalized in all immune deposits and in all injured glomeruli, tubular basement membranes, and vessel walls. Other than within immune deposits, S and C5b-9 were usually not colocalized with C3. This study demonstrates that S is deposited in areas of tissue injury and thus may participate in the pathogenesis of renal damage. Because in tissue S and C5b-9 are always associated, the attack complex in tissue must either be derived from the circulation as SC5b-9 or it must be capable of binding S after the formation in situ of C5b-9.
mesh_terms: D000838:Anions / Q000378:metabolism; D000911:Antibodies, Monoclonal; D015938:Complement Membrane Attack Complex; D003165:Complement System Proteins / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D007674:Kidney Diseases / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000378:metabolism; D011485:Protein Binding; D017293:Protein S; D012995:Solubility
chemical_list: D000838:Anions; D000911:Antibodies, Monoclonal; D015938:Complement Membrane Attack Complex; D006023:Glycoproteins; D007136:Immunoglobulins; D017293:Protein S; D003165:Complement System Proteins