IMMUNOGEN DESIGN BASED ON B-CELL LINE DIFFERENTIATION USING HUMANISED ANIMALS

FIELD: biochemistry.SUBSTANCE: invention relates to biochemistry and is a method for screening a wide range of antibody action against an antigen of interest from a pathogen that is HIV, an influenza virus or a hepatitis C virus, comprising: (a) administering a first immunogen derived from the antigen of interest, to a mouse from a line of mice containing in its germ line: (i) a restricted immunoglobulin heavy chain locus containing a single human unconverted gene segment V, which is the human gene segment V1-69 or a polymorphic variant thereof, one or more human gene segments Dand one or more human gene segments Joperably linked with the nucleotide sequence of the constant region of the heavy chain, (ii) a genetically modified immunoglobulin light chain locus containing one or more human gene segments Vκ and one or more human gene segments Jκ, wherein the gene segments Vκ and Jκ are operably linked to the nucleotide sequence of the light chain constant region, and wherein the first immunogen contains a plurality of epitopes; (b) allowing the mouse to develop an immune response to the first immunogen, wherein the immune response involves the generation of mouse B cells that express the VDJ sequences of the human immunoglobulin heavy chain (IgH) and the VJ sequences of the human immunoglobulin light chain (IgL); (c) isolating clonally related B cells from a mouse that expresses a B cell receptor (BCR) that specifically binds the first epitope of the first immunogen; (d) determining the amino acid sequences of the VDJ IgH and VJ IgL of said B-cell receptor (BCR) of clonally related B cells; (e) obtaining, from the VDJ IgH and VJ IgL sequences, the amino acid sequences VDJ and VJ of the unmutated B cell receptor (BCR); and one or more amino acid sequences of the VDJ and VJ of the intermediate B-cell receptor (BCR) precursor of said B cells at an intermediate differentiation step; (f) providing a plurality of second immunogens comprising second epitopes different from the first epitope, which bind with high affinity to the unmutated B cell receptor (BCR) or the intermediate precursor of the B cell receptor (BCR) compared to the first immunogen; (g) serial administration of another mouse of said line with second immunogens selected from the plurality of second immunogens from step (f), serial administration, starting from the second immunogen, to unmutated BCR and then the second immunogens into the intermediate BCR successively more phylogenetically removed fr