NZ810163A - Mice that make binding proteins comprising vl domains - Google Patents

Abstract

In vitro methods are provided for making an antigen-binding protein or an in vitro expression system for expressing the antigen-binding protein, wherein the method comprises obtaining a nucleotide sequence encoding a VL domain from a gene encoding a VL domain fused to a mouse CH isotype from a cell of a mouse, cloning the nucleotide sequence encoding the VL domain in frame with a gene encoding a first human CH isotype to form a human antigen-binding protein sequence, and expressing the human antigen-binding protein sequence in a suitable isolated cell, wherein the mouse comprises in its germline (i) an unrearranged human light chain V segment and an unrearranged human light chain J segment operably linked with a heavy chain constant region (CH) nucleic acid sequence that encodes a CH domain capable of associating with a light chain constant domain, and (ii) an unrearranged human light chain V segment and an unrearranged human light chain J segment operably linked to a light chain constant region (CL) gene, wherein the mouse expresses an antigen-binding protein comprising: (i) a first polypeptide comprising a first human immunoglobulin light chain variable domain (VL1) fused with a first immunoglobulin CH domain; and (ii) a second polypeptide comprising a second human immunoglobulin light chain variable domain (VL2) fused with a first immunoglobulin CL domain, and wherein neither the human VL1 nor the human VL2 contain an amino acid sequence derived from a DH gene segment. Also provided are antigen-binding proteins or in vitro expression systems made according to the above method.