YFC51.1

Antibody Name: YFC51.1
References: Sims, M.J., Hassal. D.G., Brett, S., Rowan, W., Lockyer, M.J., Angel, A., Lewis, A.P., Hale, G., Waldmann, H. and Crowe, J.S. "A humanized CD18 antibody can block function without cell destruction. J. Immunol." (1993) 151: 2296-2308.
Donor Antibody: rat
Acceptor Antibody: Human IgG1/IgG4 | k
Antigen: Human Leukocyte functional Ag-1 (LFA-1) B-chain (CD18) but different epitope to 60.3.
Laboratory: Wellcome Research Labs, UK; Cambridge University, UK
Design: "Best-fit" strategy. V regions (up to JH and JL) were compared with Kabat Ed. V. 1991 and Genbank, matching CDR length and FR identity.
Frameworks: VH NEW | VL REI (CDR-H2 was one residue longer in NEW) (sequences from Campath-1H).
CDRs: All 6 VH and VL, Kabat Definition.
Backmutations: VH S27F S30T as in Campath-1H
Binding: In vitro assays (inhibition of T cell proliferation, ADCC and failure of C1q to bind mAb-coated cells) show that the humanised mAb retains the blocking characteristics of the rat mAb. However, the humanised mAb (although associated with IgG1) was unable to bind human C1q and was not lytic in ADCC assays, thus retaining the potentially therapeutic qualities of the rat mAb.
Expression: Using Celltech's gs vectors, transiently in cos cells and stable expression in NS0.
Comment: Celltech's glutamine synthase vectors allows integration of plasmids and selection of those containing both heavy and light chains.
Clinical Indication: To prevent influx of leukocytes in sepsis or reperfusion injury, adult respiratory distress syndrome and graft rejection.

explanation of symbols and abbreviations

José Saldanha © 1997-8. Birkbeck College, London WC1E 7HX.