title: Generation of the primary antibody repertoire in rabbits: expression of a diverse set of Igk-V genes may compensate for limited combinatorial diversity at the heavy chain locus.
abstract: In mouse and human, generation of combinatorial diversity through use of different heavy and light chain variable region genes in immunoglobulin rearrangements can be a major contributor to the primary antibody repertoire. In rabbits, the contribution of the combinatorial mechanism to heavy chain diversity is minimal, as only a few Igh-V genes are rearranged and expressed. To investigate the contribution of combinatorial diversity toward generation of the rabbit V(kappa) repertoire, we constructed five genomic libraries from rabbit kidney DNA and 1 cDNA library from the bone marrow of a 1-day-old rabbit using a series of polymerase chain reaction-based strategies. Our analyses indicate that most of the sequences that we recovered from our libraries belong to a single family and some are extremely similar. The actual number of germline Igk-V genes is potentially greater than our conservative estimate of at least 39, 28 of which we found expressed as mRNA. The germline Igk-V genes display different lengths of the coding region 3' of Cys 88 ranging from 7 to 12 amino acids, resulting in CDR3 length heterogeneity among functional V(kappa)J(kappa) sequences ranging from 8 to 15 amino acids. Some of the V(kappa)J(kappa) junctions had N and P nucleotide additions. Thus, in contrast to limited combinatorial diversity of its heavy chain, the rabbit can draw upon a diverse set of germline Igk-V genes. The kappa light chain has the potential to be a major contributor toward generation of the antibody specificities of the rabbit pre-immune repertoire.
authors.affiliation: Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1892, USA.
authors.forename: D
authors.initials: D
authors.lastname: Sehgal
authors.forename: G
authors.initials: G
authors.lastname: Johnson
authors.forename: T T
authors.initials: TT
authors.lastname: Wu
authors.forename: R G
authors.initials: RG
authors.lastname: Mage
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D001483:Base Sequence; D001853:Bone Marrow; D019070:Cell Lineage; D015870:Gene Expression; D015723:Gene Library; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D015698:Genomic Library; D005854:Germ Cells; D007133:Immunoglobulin Joining Region / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000145:classification / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000145:classification / Q000235:genetics*; D007668:Kidney; D008969:Molecular Sequence Data; D011817:Rabbits / Q000235:genetics* / Q000276:immunology; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D007133:Immunoglobulin Joining Region; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains