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The cleavage site of C5 from man and animals as a common target for neutralizing human monoclonal antibodies: in vitro and in vivo studies.

AbstractThe isolation of an anti-C5 single-chain fragment variable (scFv) antibody, TS-A12/22, from a human phage display library, is described. This antibody inhibits the activation of C5 and the assembly of the terminal complement complex implicated in cell and tissue damage. Using antibody-sensitized sheep erythrocytes and rabbit red cells as target cells in hemolytic assays, we found that TS-A12/22 inhibited the activation of C5 by the convertases of both classical and alternative pathways. Western blot analysis and competition experiments with synthetic peptides showed that TS-A12/22 reacted with the alpha chain of C5 and recognized the cleavage site of this complement component by the C5 convertase. As a result, the antibody prevented splitting of C5 and inhibited the generation of C5a and of the terminal complement complex. The identification of the TS-A12/22 recognition site as a conserved sequence in man, mouse, rat and rabbit enabled the demonstration of in vitro inhibition of complement activity in these species. The scFv TS-A12/22 was tested in a rat model of antigen-induced arthritis and proved to be effective in preventing influx of polymorphonuclear cells into the knee joint and C9 deposition on synovial tissue.
AuthorsRoberto Marzari, Daniele Sblattero, Paolo Macor, Fabio Fischetti, Renato Gennaro, James D Marks, Andrew Bradbury, Francesco Tedesco (Affiliation: Department of Biology, University of Trieste, Via Fleming 22, I-34127 Trieste, Italy.)
JournalEuropean journal of immunology (Eur J Immunol) Vol. 32 Issue 10 Pg. 2773-82 (Oct 2002) ISSN: 0014-2980 Germany
PMID12355429 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
Chemical References
  • Antibodies, Monoclonal
  • Complement C5
  • Immunoglobulin Fragments
  • Peptide Library
  • immunoglobulin Fv
Topics
  • Animals
  • Antibodies, Monoclonal (immunology)
  • Arthritis (prevention & control)
  • Complement C5 (immunology, metabolism)
  • Female
  • Humans
  • Immunoglobulin Fragments (immunology)
  • Mice
  • Mice, Inbred CBA
  • Peptide Library
  • Rats
  • Rats, Wistar