Human immunoglobulin heavy-chain minilocus recombination in transgenic mice: gene-segment use in mu and gamma transcripts.
We (N.L. and L.D.T.) have introduced a human heavy-chain minilocus into mice transgenically. Constructs contain 2 heavy-chain variable (VH; psi VH3-105 and VH5-251), 10 diversity (D), 6 heavy-chain joining (JH), and either constant (C)mu or C mu and C gamma gene segments. Several founder lines were established and studied before immunization. Seventy heavy-chain transcripts were cloned and sequenced from murine splenic B lymphocytes, and gene-segment use was assessed before and after class-switching. In general, the repertoire was "fetal" in appearance with little evidence of somatic mutation in any gene segment. The two VH gene segments were found rearranged to mu- and gamma-chain C segments, with a preference of VH5-251. We observed a preponderance of the most-J-proximal D gene (DHQ52) segments among the mu transcripts (44%). The JH gene-segment use mimics most patterns seen in human antibodies. Diversification in CDR3 was extensive and included clear examples of D inversions and D-D fusions. These data suggest that a human immunoglobulin minilocus can undergo recombinatorial processes in a manner analogous to that seen in the human fetal/preimmune repertoire. This model, in addition to providing a potential source of human monoclonal antibodies, is ideal for the study of further questions concerning immunoglobulin gene-segment recombination.
Tuaillon
N
N
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235.
Taylor
L D
LD
Lonberg
N
N
Tucker
P W
PW
Capra
J D
JD
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D005787:Gene Frequency; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007133:Immunoglobulin Joining Region / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D007142:Immunoglobulin gamma-Chains / Q000235:genetics*; D007148:Immunoglobulin mu-Chains / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction / Q000379:methods; D011995:Recombination, Genetic; D017386:Sequence Homology, Amino Acid; D013154:Spleen / Q000276:immunology; D014158:Transcription, Genetic
D007127:Immunoglobulin Constant Regions; D007143:Immunoglobulin Heavy Chains; D007133:Immunoglobulin Joining Region; D007135:Immunoglobulin Variable Region; D007142:Immunoglobulin gamma-Chains; D007148:Immunoglobulin mu-Chains; D009838:Oligodeoxyribonucleotides; D004247:DNA