title: Complement activation is variably affected by fibronectin preparations obtained through different procedures.
abstract: Human plasma fibronectin (FN) containing preparations (FNCP) were prepared by means of gelatin-affinity chromatography of normal plasma cryoprecipitate (FNCP-a), and by affinity chromatography of cryoprecipitate on a rabbit anti-human FN antiserum Sepharose column (FNCP-b) or of normal citrated plasma (FNCP-c). These preparations were then tested for their ability to influence certain complement (C')-dependent polymorphonuclear phagocyte activities. FNCP-a consistently inhibited humoral chemotaxis, whereas FNCP-b and -c did not. Measurement of C' activation by the C3 conversion assay revealed that only FNCP-a displayed inhibitory activity on classical and alternative pathways. Ouchterlony and immunoelectrophoretic analyses indicated substantial identity of all FNCPs. FNCP-a contained a consistent amount of lower MW contaminants (between 40 and 60 KD) which were shown not to be immunologically related to FN by Western blot analysis. Immunoblotting also revealed a single band in FNCP-a (MW approx. 210 KD) instead of the anticipated two bands which were evident in the other FNCPs. Thus, a slight modification of the FN molecule and/or the presence of low MW contaminants in the gelatin-purified preparation seem able to induce inhibitory effects on C'-dependent polymorphonuclear phagocytic activities.
authors.affiliation: Department of Allergy and Clinical Immunology, University of Rome La Sapienza, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Fattorossi
authors.forename: S
authors.initials: S
authors.lastname: Le Moli
authors.forename: O
authors.initials: O
authors.lastname: Pontesilli
authors.forename: A
authors.initials: A
authors.lastname: Aiuti
authors.forename: R
authors.initials: R
authors.lastname: Nisini
authors.forename: E
authors.initials: E
authors.lastname: Galli
authors.forename: M
authors.initials: M
authors.lastname: Carbonari
authors.forename: R
authors.initials: R
authors.lastname: D'Amelio
mesh_terms: D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D003167:Complement Activation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005353:Fibronectins / Q000138:chemical synthesis / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects; D010587:Phagocytosis / Q000187:drug effects
chemical_list: D005353:Fibronectins