Phage-derived monoclonal anti-Lu.
BACKGROUND
Monoclonal antibodies (MoAbs) are gradually replacing human polyclonal sera as typing reagents. Many blood group specificities, however, are not amenable to classic hybridoma technology. The phage display technology, aimed at isolating peptides or antibody fragments, offers an alternative strategy. Recombinant antibodies derived from this technology would greatly facilitate phenotyping and decrease analysis cost.


METHODS
A human single-chain Fv (scFv) phage-displayed library was panned on red blood cells (RBCs) in an attempt to isolate clones recognizing human RBC specificities. Three rounds of biopanning were performed. Enrichment was monitored by phage titration, and selected phage populations were analyzed further.


RESULTS
Three major clones were identified by clone diversity analysis. One of them showed a specificity for Lua. This scFv was reconstructed into a human IgG1 by recombinant DNA methods. The reactivity of the reconstructed human IgG1 toward Lua is indistinguishable from its parent scFv. Moreover, the specificity of the antibody was confirmed by serologic assays, flow cytometry, and biochemical analysis with RBCs of different Lu phenotypes and a recombinant cell line expressing Lu glycoproteins.


CONCLUSIONS
With phage display and standard recombinant DNA methods, isolation of a scFv of Lua specificity was successful, from which a complete human IgG1 MoAb of equivalent reactivity was reconstructed. To our knowledge, this is the first MoAb specific for Lua.
Richard
Martine
M
From Research and Development, Héma-Québec, Sainte-Foy, Québec, Canada.
Perreault
Josée
J
Gane
Pierre
P
el Nemer
Wassim
W
Cartron
Jean-Pierre
JP
St-Louis
Maryse
M
D000911:Antibodies, Monoclonal; D001435:Bacteriophages / Q000276:immunology*; D001788:Blood Grouping and Crossmatching / Q000379:methods*; D015815:Cell Adhesion Molecules / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology; D006801:Humans; D007135:Immunoglobulin Variable Region; D008188:Lutheran Blood-Group System / Q000276:immunology; D009363:Neoplasm Proteins / Q000276:immunology*; D019151:Peptide Library
D000911:Antibodies, Monoclonal; C090228:BCAM protein, human; D015815:Cell Adhesion Molecules; D007135:Immunoglobulin Variable Region; D008188:Lutheran Blood-Group System; D009363:Neoplasm Proteins; D019151:Peptide Library