Direct selection of a human antibody fragment directed against the tumor T-cell epitope HLA-A1-MAGE-A1 from a nonimmunized phage-Fab library.
Antitumor antibodies with the same specificity as cytotoxic T lymphocytes that recognize antigenic peptides encoded by tumor-associated genes and presented by MHC class I molecules would be valuable tools to analyze the antigenicity or target tumor cells in vivo. To obtain a human antibody directed against a peptide encoded by gene melanoma-associated antigen (MAGE)-A1 and presented by HLA-A1 molecules, we selected a large phage Fab antibody repertoire on a recombinant version of the complex HLA-A1-MAGE-A1 produced by in vitro refolding. One of the selected phage antibodies shows binding to HLA-A1 complexed with the MAGE-A1 peptide, but does not show binding to HLA-A1 complexed with a peptide encoded by gene MAGE-A3 and differing from the MAGE-A1 peptide by only three residues. Phages carrying this recombinant antibody bind to HLA-A1(+) cells only after in vitro loading with MAGE-A1 peptide. These results indicate that nonimmunized phage Fab libraries are a source of antibodies with a T cell antigen receptor-like specificity. The human anti-HLA-A1-MAGE-A1 antibody described here may prove very useful for monitoring the cell surface expression of these complexes, and eventually, as a targeting reagent for the specific immunotherapy of HLA-A1 patients bearing a MAGE-A1-positive tumor.
Chames
P
P
Department of Pathology, Maastricht University, and University Hospital Maastricht, P.O. Box 5800, 6202AZ Maastricht, The Netherlands.
Hufton
S E
SE
Coulie
P G
PG
Uchanska-Ziegler
B
B
Hoogenboom
H R
HR
D000912:Antibodies, Neoplasm / Q000235:genetics*; D017951:Antigen Presentation; D000943:Antigens, Differentiation; D000951:Antigens, Neoplasm; D015374:Biosensing Techniques; D003001:Cloning, Molecular; D000939:Epitopes; D005434:Flow Cytometry; D015788:HLA-A1 Antigen / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000235:genetics*; D008545:Melanoma / Q000276:immunology*; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins / Q000276:immunology* / Q000302:isolation & purification; D019151:Peptide Library; D017510:Protein Folding; D012641:Selection, Genetic; D013601:T-Lymphocytes / Q000276:immunology*
D000912:Antibodies, Neoplasm; D000943:Antigens, Differentiation; D000951:Antigens, Neoplasm; D000939:Epitopes; D015788:HLA-A1 Antigen; D007140:Immunoglobulin Fab Fragments; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D019151:Peptide Library