title: [Activation of the alternative pathway of human complement (author's transl)].
abstract: The C3 amplification convertase of human complement, C3b, Bb, is assembled on biological surfaces by the interaction of the alternative pathway proteins B, D and P with cell-bound C3b. Convertase formation is modulated by the action of the regulatory proteins H and I. On activating surfaces of the alternative pathway, C3b, Bb is relatively resistant to regulation by H. In contrast, non-activating surfaces exhibit surface characteristics such as high content in membrane-associated sialic acid or heparin-related material which increase the interaction of H with cell-bound C3b. Thus, finely tuned molecular interactions allow the alternative pathway to function as a major recognition and effector system for natural defence.
mesh_terms: D000594:Amino Acid Oxidoreductases; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D003167:Complement Activation; D050577:Complement C3-C5 Convertases / Q000378:metabolism; D011415:Complement Factor B / Q000378:metabolism; D011416:Complement Factor D / Q000378:metabolism; D003170:Complement Pathway, Alternative; D050841:Glycine Dehydrogenase (Decarboxylating); D006801:Humans; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism; D011951:Receptors, Complement
chemical_list: D002352:Carrier Proteins; D011951:Receptors, Complement; D000594:Amino Acid Oxidoreductases; D050841:Glycine Dehydrogenase (Decarboxylating); D050577:Complement C3-C5 Convertases; C493488:CFD protein, human; D011416:Complement Factor D; D011415:Complement Factor B
vernacular_title: Activation de la voie alterne du complément par les surfaces biologiques.