title: A quasi-monoclonal mouse.
abstract: As a model for studying the generation of antibody diversity, a gene-targeted mouse was produced that is hemizygous for a rearranged V(D)J segment at the immunoglobulin (Ig) heavy chain locus, the other allele being nonfunctional. The mouse also has no functional kappa light chain allele. The heavy chain, when paired with any lambda light chain, is specific for the hapten (4-hydroxy-3-nitrophenyl) acetyl (NP). The primary repertoire of this quasi-monoclonal mouse is monospecific, but somatic hypermutation and secondary rearrangements change the specificity of 20 percent of the antigen receptors on B cells. The serum concentrations of the Ig isotypes are similar to those in nontransgenic littermates, but less than half of the serum IgM binds to NP, and none of the other isotypes do. Thus, neither network interactions nor random activation of a small fraction of the B cell population can account for serum Ig concentrations.
authors.affiliation: Department of Microbiology and Immunology, University of California, San Francisco 94143-0670, USA.
authors.forename: M
authors.initials: M
authors.lastname: Cascalho
authors.forename: A
authors.initials: A
authors.lastname: Ma
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: L
authors.initials: L
authors.lastname: Masat
authors.forename: M
authors.initials: M
authors.lastname: Wabl
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics* / Q000276:immunology; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA; D005434:Flow Cytometry; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D006241:Haptens / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics* / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000235:genetics; D007144:Immunoglobulin J-Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000235:genetics; D017493:Leukocyte Common Antigens / Q000276:immunology; D051917:Leukosialin; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D009596:Nitrophenols / Q000276:immunology; D010648:Phenylacetates; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012795:Sialoglycoproteins / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D006241:Haptens; D007143:Immunoglobulin Heavy Chains; D007132:Immunoglobulin Isotypes; D007144:Immunoglobulin J-Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D051917:Leukosialin; D009596:Nitrophenols; D010648:Phenylacetates; D011994:Recombinant Proteins; D012795:Sialoglycoproteins; C497863:Spn protein, mouse; C026242:4-hydroxy-5-nitrophenyl acetic acid; D004247:DNA; D017493:Leukocyte Common Antigens