title: Generation of chimeric monoclonal antibodies from mice that carry human immunoglobulin Cgamma1 heavy of Ckappa light chain gene segments.
abstract: Gene targeting in mouse embryonic stem (ES) cells was used to replace (i) the mouse immunoglobulin heavy chain (IgH) Cgamma2a gene segment (mCgamma2a) with the human Cgamma1 gene segment (hCgamma1), and (ii) the mouse immunoglobulin light chain (IgL) Ckappa gene segment (mC kappa) with its human counterpart (hC kappa). ES cells carrying these gene conversions were used to generate chimeric mice that transmitted the human alleles through the germ line. Mice homozygous for both gene alterations were generated by breeding. Serum from homozygous mutant mice contained comparable amounts of antibodies with chimeric kappa or mouse lambda light chains but only small fractions of basal serum IgG or antibodies elicited against immunizing agents contained chimeric heavy chains. A relative increase in immunogen-specific hCgamma1 antibodies was seen following immunization in combination with the saponin adjuvant QS-21. The effect of this was to shift the IgG1-dominated response to an IgG subclass profile that included significant amounts of IgG2a, IgG2b and IgG3 and chimeric IgG. The amounts of antibody secreted by hybridomas derived from mutant and wild-type mice were similar. Sequencing confirmed correct splicing of hCgamma1 and hCkappa gene segments to mouse J gene segments in hybridoma Ig gene transcripts. In conclusion, IgHhCgamma1/IgLhCkappa double mutant mice provide a useful animal model for deriving humanized antibodies with potential applications in immunotherapy and diagnostics in vivo as well as for investigating hCgamma1 associated functions.
authors.affiliation: Swiss Tropical Institute, Basel, Switzerland. pluschke@ubaclu.unibas.ch
authors.forename: G
authors.initials: G
authors.lastname: Pluschke
authors.forename: A
authors.initials: A
authors.lastname: Joss
authors.forename: J
authors.initials: J
authors.lastname: Marfurt
authors.forename: C
authors.initials: C
authors.lastname: Daubenberger
authors.forename: O
authors.initials: O
authors.lastname: Kashala
authors.forename: M
authors.initials: M
authors.lastname: Zwickl
authors.forename: A
authors.initials: A
authors.lastname: Stief
authors.forename: G
authors.initials: G
authors.lastname: Sansig
authors.forename: B
authors.initials: B
authors.lastname: Schläpfer
authors.forename: S
authors.initials: S
authors.lastname: Linkert
authors.forename: H
authors.initials: H
authors.lastname: van der Putten
authors.forename: N
authors.initials: N
authors.lastname: Hardman
authors.forename: M
authors.initials: M
authors.lastname: Schröder
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000235:genetics* / Q000276:immunology; D000918:Antibody Specificity; D001483:Base Sequence; D003001:Cloning, Molecular; D004622:Embryo, Mammalian; D005260:Female; D005434:Flow Cytometry; D018390:Gene Targeting; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood / Q000235:genetics; D007142:Immunoglobulin gamma-Chains / Q000096:biosynthesis* / Q000235:genetics* / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000096:biosynthesis* / Q000235:genetics* / Q000276:immunology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000235:genetics* / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D007142:Immunoglobulin gamma-Chains; D007145:Immunoglobulin kappa-Chains; D011993:Recombinant Fusion Proteins