An antibody fragment from a phage display library competes for ligand binding to the low density lipoprotein receptor family and inhibits rhinovirus infection.
Recently antibodies with a wide range of binding specificities have been isolated from large repertoires of antibody fragments displayed on filamentous phage, including those that are difficult to raise by immunization. We have used this approach to isolate an antibody fragment against chicken very low density lipoprotein (VLDL) receptor. It binds to the receptor with good affinity (Kaff = 2 x 10(8) M-1) as measured by plasmon surface resonance, and competes for binding of natural ligands (vitellogenin, VLDL, and receptor-associated protein). The antibody also binds to other members of the low density lipoprotein (LDL) receptor family including rat LDL receptor and human and rat low density lipoprotein receptor-related protein (LRP/alpha 2MR), and it competes for binding of receptor-associated protein to LRP/alpha 2MR. Moreover, the antibody fragment inhibits infection of human fibroblasts deficient in LDL-R but expressing LRP/alpha 2MR by human rhinovirus. Binding of the antibody is abolished upon reduction of the receptors and is strictly Ca2+ dependent. The phage antibody thus recognizes the ligand binding site(s) of several members of the LDL receptor family, in contrast to antibodies produced by hybridoma technology.
Hodits
R A
RA
Institute of Biochemistry, University of Vienna, Austria.
Nimpf
J
J
Pfistermueller
D M
DM
Hiesberger
T
T
Schneider
W J
WJ
Vaughan
T J
TJ
Johnson
K S
KS
Haumer
M
M
Kuechler
E
E
Winter
G
G
D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D001667:Binding, Competitive; D015153:Blotting, Western; D002460:Cell Line; D002645:Chickens; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D003090:Coliphages; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D005260:Female; D015723:Gene Library; D006801:Humans; D007128:Immunoglobulin Fragments / Q000378:metabolism*; D007700:Kinetics; D008079:Lipoproteins, VLDL / Q000097:blood / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D010058:Oviposition; D051381:Rats; D011973:Receptors, LDL / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D012229:Rhinovirus / Q000276:immunology / Q000472:pathogenicity / Q000502:physiology*; D013045:Species Specificity; D014162:Transfection
D007128:Immunoglobulin Fragments; D008079:Lipoproteins, VLDL; D011973:Receptors, LDL; D011994:Recombinant Proteins