Designed ankyrin repeat proteins as anti-idiotypic-binding molecules.
According to the network theory antibodies may act as antigens thus generating anti-idiotypic antibodies that can function as regulators of immune responses. Designed ankyrin repeat proteins (DARPins) are a new class of binding proteins and may serve as an alternative to antibodies. Selections from large DARPin libraries against the variable regions of a murine monoclonal anti-human IgE antibody, termed BSW17, yielded two highly specific anti-idiotypic DARPins both with high affinity. Their binding characteristics were comparable with these of a previously selected anti-idiotypic antibody. In vitro cell assays showed that the anti-idiotypic DARPins were able to inhibit the binding of BSW17 to cell-bound IgE and prevented BSW17 functional activity. These experiments demonstrate the possibility to isolate anti-idiotypic DARPins recognizing idiotypic determinants analogous to antibodies. In the future these DARPins may be further analyzed for their potential as putative vaccine candidates.
Vogel
Monique
M
Institute of Immunology, Inselspital, 3010 Bern, Switzerland. Monique.vogel@iib.unibe.ch
Keller-Gautschi
Elsbeth
E
Baumann
Michael J
MJ
Amstutz
Patrick
P
Ruf
Christine
C
Kricek
Franz
F
Stadler
Beda M
BM
D000818:Animals; D017089:Ankyrin Repeat / Q000276:immunology*; D000888:Antibodies, Anti-Idiotypic / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D006801:Humans; D051379:Mice; D015202:Protein Engineering; D051381:Rats; D017455:Receptors, IgE / Q000235:genetics / Q000276:immunology / Q000378:metabolism