Construction of bacteriophage expressing mouse monoclonal Fab fragments directed against the human MN glycophorin blood group antigens.
BACKGROUND
The MN human blood group antigens are complex glycopeptide antigens at the amino terminus of glycophorin A. Many different mouse monoclonal antibodies to these antigens have been produced and characterized. The construction of combinatorial immunoglobulin libraries displaying antibody Fab fragments on the surface of bacteriophage (Fab-phage) represents a novel approach for developing monoclonal reagents, for exploring the diversity of the immune response to specific antigens, and for understanding the molecular basis of the interaction of an antibody with its antigen. However, it is necessary to determine whether Fab fragments displayed on bacteriophage surfaces retain immunologic characteristics similar to the intact antibodies.


METHODS
Fab-phage were constructed from three anti-N (AH7, N61, and N92) and two anti-M (425/2B and M2A1) murine hybridomas. The Fab-phage and parental hybridomas were compared by enzyme-linked immunosorbent assay, Western blotting, and flow cytometry.


RESULTS
In each case, the Fab-phage and its parental hybridoma antibody had similar immunologic characteristics. In particular, their dependence on the pH of the buffer and on sialylation of the target antigen was similar.


CONCLUSIONS
These results suggest that Fab-phage may provide novel reagents with applications in immunohematology and may be useful in the study of the immune response to human blood group antigens.
Czerwinski
M
M
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia.
Siegel
D L
DL
Moore
J S
JS
Spitalnik
P F
PF
Spitalnik
S L
SL
D000818:Animals; D000911:Antibodies, Monoclonal; D001435:Bacteriophages / Q000276:immunology*; D001483:Base Sequence; D015153:Blotting, Western; D002678:Chimera; D005434:Flow Cytometry; D006021:Glycophorins / Q000276:immunology*; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology*; D008951:MNSs Blood-Group System / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid; D011485:Protein Binding; D012794:Sialic Acids / Q000502:physiology
D000911:Antibodies, Monoclonal; D006021:Glycophorins; D007140:Immunoglobulin Fab Fragments; D008951:MNSs Blood-Group System; D012794:Sialic Acids; D019158:N-Acetylneuraminic Acid