B6.Cg-Cd80^tm1Shr Cd86^tm2Shr Tg(Cd80)1Hode/J

Stock number: 036705
Product name: B7.1 flox

Research areas: Developmental Biology Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools

Description

B7.1 floxed mice have the endogenous Cd80 and Cd86 loci deleted, and have a transgene carrying the murine Cd80 sequence with exon 2 flanked by loxP sites, allowing for Cre-mediated cessation of CD80 expression. These mice may be useful in studying immunology and germinal center responses.

Detailed description

Cd80 (also known as B7.1) is expressed in multiple cell types including dendritic cells and B cells and is critical for germinal center formation and cell differentiation. Disruption of the CD80/CD86 ligand-CD28 receptor pathway results in defects in the formation of germinal centers and impaired antigen-specific class-switched antibody production.

B7.1 floxed mice have the endogenous Cd80 and Cd86 loci deleted, and have a transgene carrying the murine Cd80 sequence with exon 2 flanked by loxP sites, allowing for Cre-mediated cessation of CD80 expression. Prior to introduction of Cre recombinase, mice heterozygous or homozygous for all three alleles are viable and fertile with normal breeding, and have no gross physical or behavioral abnormalities.

When B7.1 floxed mice are bred to mice that express Cre recombinase, the resulting offspring will have exon 2 deleted - creating a null allele in the cells/tissues as determined by the Cre promoter.
For example, when bred to dendritic cell-specific CD11c-Cre (such as Itgax-cre; see Stock No. 008068), the resulting "DC-B7 cKO" mice exhibit impaired generation of antigen-specific follicular helper T cells, antigen-specific germinal center B cells, and high-affinity class-switched antibody production (Watanabe et al., 2017).

Development

The B7.1 flox allele (also known as B7.1^flox BAC Tg) was generated in the laboratory of Dr. Richard Hodes (NIA, NCI, NIH). In brief, loxP sites were inserted flanking exon 2 of the mouse Cd80 gene contained within a bacterial artificial chromosome (RP23-206M14; Accession No. AC209577.2). The engineered BAC DNA was linearized by NotI digestion, purified and injected into C57BL/6NCrl-derived fertilized eggs. Founder lines positive for the transgene were backcrossed to constitutive B7 double knock-out mice (Stock No. 003610) to generate triple mutant B7.1^flox BAC Tg DKO mice. Males were sent to The Jackson Laboratory Repository and, upon arrival, sperm cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

In 2022, a 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. One of the 43 markers throughout the genome, on Chromosome 13, was segregating with an unknown source.

Allele

Symbol: Cd80^tm1Shr
Name: targeted mutation 1, Arlene H Sharpe
MGI accession ID: MGI:1861804
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: B7-; B7.1; B7-1-; CD80-
Marker symbol: Cd80
Marker name: CD80 antigen
Marker synonyms: B7; B7.1; B7-1; BB1; Cd28l; CD28LG; CD28LG1; LAB7; Ly53; Ly-53
Chromosome: 16
Strain of origin: 129S4/SvJae
Molecular note: A neomycin selection cassette replaced the exon encoding the IgV-like domain of the protein. RT-PCR analysis on RNA derived from spleen, thymus and LPS-stimulated B cells of homozygous mice demonstrated that no detectable transcript was produced from this allele. FACS analysis on B cells derived from homozygous mice confirmed that no functional protein was encoded by this allele.

Allele

Symbol: Cd86^tm2Shr
Name: targeted mutation 2, Arlene H Sharpe
MGI accession ID: MGI:2159105
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: B7.1/B7.2-; B7-1/2-; B7-1/B7-2-; B7DKO; B7KO; Cd80/86^-
Marker symbol: Cd86
Marker name: CD86 antigen
Marker synonyms: B7.2; B70; B7-2; BU63; Cd28l2; CD28LG2; CD86 v6; FUN-1; LAB72; Ly58; Ly-58; MB7-2
Chromosome: 16
Strain of origin: 129S4/SvJae
Molecular note: To create a knockout of both Cd80 and Cd86 in mice, an ES cell line in which the Cd80 gene was mutated was subsequently used in a second round of gene targeting. A hygromycin selection cassette replaced an exon encoding the IgV-like domain of the protein and flanking genomic sequences of the Cd86 gene. FACS analysis on splenocytes and LPS-stimulated B cells derived from homozygous mice confirmed that no functional protein was encoded by this allele.

Allele

Symbol: Tg(Cd80)1Hode
Name: transgene insertion 1, Richard Hodes
MGI accession ID: MGI:6834803
Generation method: Transgenic
Attributes: Conditional ready (e.g. floxed); Inserted expressed sequence
Synonyms: B7.1^flox BAC Tg
Marker symbol: Tg(Cd80)1Hode
Marker name: transgene insertion 1, Richard Hodes
Chromosome: UN
Strain of origin: C57BL/6NCrl
Molecular note: A bacterial artificial chromosome (RP23-206M14; Accession No. AC209577.2) containing the full length Cd80 gene is modified to include loxP sites flanking exon 2.