A modular IgG-scFv bispecific antibody topology.
Here we present a bispecific antibody (bsAb) format in which a disulfide-stabilized scFv is fused to the C-terminus of the light chain of an IgG to create an IgG-scFv bifunctional antibody. When expressed in mammalian cells and purified by one-step protein A chromatography, the bsAb retains parental affinities of each binding domain, exhibits IgG-like stability and demonstrates in vivo IgG-like tumor targeting and blood clearance. The extension of the C-terminus of the light chain of an IgG with an scFv or even a smaller peptide does appear to disrupt disulfide bond formation between the light and heavy chains; however, this does not appear to affect binding, stability or in vivo properties of the IgG. Thus, we demonstrate here that the light chain of an IgG can be extended with an scFv without affecting IgG function and stability. This format serves as a standardized platform for the construction of functional bsAbs.
Orcutt
Kelly Davis
KD
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Ackerman
Margaret E
ME
Cieslewicz
Maryelise
M
Quiroz
Emmanuel
E
Slusarczyk
Adrian L
AL
Frangioni
John V
JV
Wittrup
K Dane
KD
D000818:Animals; D018033:Antibodies, Bispecific / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D019151:Peptide Library; D057127:Single-Chain Antibodies / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism
D018033:Antibodies, Bispecific; D007074:Immunoglobulin G; D019151:Peptide Library; D057127:Single-Chain Antibodies