| abstract |
A method for selecting a human heavy chain variable region to prepare a bispecific antibody comprising: (a) immunizing a genetically modified mouse with an antigen of interest, wherein the mouse comprises (i) a substitution in the endogenous locus of the region mouse κ light chain variable of all endogenous genetic segments of the mouse immunoglobulin Vκ light chain variable region with a rearranged human Vκ 1-39 / J genetic segment, a human Vκ 3-20 / J genetic segment rearranged or a combination thereof, wherein the rearranged human genetic segment is operatively linked to a gene of the mouse κ constant region, where the mouse lacks an endogenous locus of the κ light chain variable region of the mouse immunoglobulin that is capable of rearranging and forming a gene that encodes a mouse κ variable region; and (ii) a 90-100% substitution of non-rearranged mouse VH genetic segments, with at least one human non-rearranged VH genetic segment, and a replacement of all endogenous mouse D and JH genetic segments with at least one non-rearranged human D genetic segment and at least one non-rearranged human JH genetic segment, wherein the human VH, D and JH genetic segments are operatively linked to an endogenous mouse heavy chain constant region gene, and the genetic segments Human VH, D and JH are able to rearrange and form a human / mouse chimeric heavy chain rearranged gene; (b) allow the mouse to develop an immune response for the antigen of interest; and, (c) identify a lymphocyte selected by mouse cloning that expresses an antibody that specifically binds the antigen of interest, and obtain from the lymphocyte or antibody a nucleotide sequence encoding a variable region of the human heavy chain that binds specifically to the antigen of interest. |