| 摘要 |
The invention discloses methods for the generation of chimaeric human-non-human antibodies and chimaeric antibody chains, antibodies and antibody chains so produced, and derivatives thereof including fully humanised antibodies; compositions comprising said antibodies, antibody chains and derivatives, as well as cells, non-human mammals and vectors, suitable for use in said methods. |
| 主权项 |
1. A method of providing an antigen-specific polypeptide comprising a human IgH variable region, antibody comprising said polypeptide, a cell producing said polypeptide, a nucleic acid encoding said polypeptide and/or a biological sample comprising said polypeptide, the method comprising providing a transgenic mouse immunized with an antigen and expressing said polypeptide,
isolating from said transgenic immunized mouse one or more of said polypeptide, said antibody comprising said polypeptide, said cell producing said polypeptide, said nucleic acid encoding said polypeptide and/or said biological sample comprising said polypeptide, wherein said transgenic mouse comprises a germline with a homozygous chimeric immunoglobulin heavy chain (IgH) locus comprising unrearranged human IgH variable region gene segments positioned within the JC intron of the endogenous IgH locus, upstream of a constant (C) region comprising an endogenous IgH C gene segment, wherein said human variable region gene segments in said chimeric IgH locus are operably linked to said C region at a human/mouse chimeric junction; wherein said homozygous chimeric IgH locus comprises in 5′ to 3′ transcriptional orientation (i) unrearranged human immunoglobulin heavy chain (IgH) variable region (VH) DNA comprising one or more human IgH V gene segments, one or more human D gene segments and one or more human JH gene segments comprising a human JH6 gene segment, (ii) a chimeric JC intron comprising human DNA downstream of and naturally contiguous with a said human JH gene segment, mouse DNA and an enhancer, wherein said chimeric JC intron comprises mouse 129 strain DNA upstream of said enhancer, wherein the 3′ end of said one or more human JH gene segments is less than 2 kb upstream from said chimeric junction; (iii) said C region; wherein said homozygous chimeric IgH locus is functional to undergo human IgH gene segment rearrangement, wherein said transgenic mouse is functional to form rearranged human VH, D and JH gene segments and to express mRNA transcripts encoding chimeric immunoglobulin heavy chain polypeptide comprising a human VH region and a mouse Cμ region, and wherein said immunized mouse forms rearranged human VH, D and JH gene segments, and expresses mRNA transcripts encoding said antigen-specific polypeptide, wherein prior to immunization said transgenic mouse comprises IgH mRNA transcripts comprising IgH-VDJCμ transcripts comprising rearranged human heavy chain V, D, and J gene segments and mouse Cμ and encoding chimeric IgH polypeptides, wherein each IgH-VDJCμ transcript encodes a human variable region comprising a CDR-H3, wherein said IgH-VDJCμ transcripts comprise transcripts encoding a human variable region comprising a CDR-H3 length of 17 amino acids and transcripts encoding human variable region comprising a CDR-H3 length of 18 amino acids, wherein the mean frequency of the group consisting of said transcripts encoding CDR-H3 lengths of 17 and 18 amino acids present in said IgH-VDJCμ transcripts of said mouse is between 5% and 10%. |
