B6(SJL)-Cd40lg^{tm1.1(icre)Tega}/J

Stock number: 039650
Product name: Cd40lg-cre
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

Cd40lg-cre knock-in mice express Cre recombinase under the direction of the X-linked Cd40lg promoter in CD4⁺ T cells.

Detailed description

Cd40lg-cre knock-in mice express Cre recombinase under the direction of the X- linked CD40 ligand (Cd40lg) gene. The presence of IRES-Cre cassette in the 3' UTR allows for expression of Cd40lg and cre. Cd40lg encodes a transmembrane protein expressed predominantly on the surface of CD4⁺ T cells and activates the receptor CD40. It regulates B cell function by engaging CD40 on the B cell surface and a subset of dendritic cells. CD40 is a receptor on antigen-presenting cells and is essential for mediating a broad variety of immune and inflammatory responses including T cell-dependent immunoglobulin class switching, memory B cell development, and germinal center formation. When these mice are bred with mice containing loxP-flanked sequence, Cre-mediated recombination will result in deletion of the floxed sequences in CD4⁺ T cells and a minority of CD8⁺ T cells of the offspring. Homozygous females and hemizygous males are viable, fertile, and immunologically competent. The donating investigator has not observed leaky germline deletion with this strain.

Development

A targeting construct was designed to insert an FRT-flanked neomycin resistance (neo) cassette and an internal ribosomal entry site (IRES) fused to a codon optimized Cre recombinase (iCre) sequence into the 3' UTR of the X-linked CD40 ligand (Cd40lg) gene. This construct was electroporated into C57BL/6N-derived JM8.N4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric Cd40lg-cre mice were bred to Actb-Flpe mice (Stock No. 005703) to remove the neo cassette. Offspring were crossed to remove the Flpe expressing gene. The donating laboratory reported the mice were further backcrossed to C57BL/6NCrl mice for at least 4 generations prior to sending to The Jackson Laboratory in 2024 (see SNP note below). Upon arrival, sperm was cryopreserved. To establish our live colony in 2024, an aliquot of frozen sperm was used to fertilize C57BL/6NJ oocytes (Stock No. 005304).

In 2024, 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 males sent to The Jackson Laboratory Repository. One of the 43 markers throughout the genome was segregating with SJL. Also, one 4 of the 5 markers that determine C57BL/6J from C57BL/6N was found to be C57BL/6J like. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background that was mostly C57BL/6J.

Allele

Symbol: Cd40lg^{tm1.1(icre)Tega}
Name: targeted mutation 1.1, Takeshi Egawa
MGI accession ID: MGI:7490227
Generation method: Targeted
Attributes: Recombinase-expressing
Synonyms: Cd40lg-cre
Marker symbol: Cd40lg
Marker name: CD40 ligand
Marker synonyms: CD154; Cd40L; gp39; hCD40L; HIGM1; IGM; IMD3; Ly-62; T-BAM; Tnfsf5; TRAP
Chromosome: X
Strain of origin: C57BL/6N
Molecular note: An IRES-icre sequence was inserted into the 3’ UTR of the Cd40lg gene by homologous recombination. After obtaining germline transmission of the targeted allele, the FRT-flanked selection cassette was removed by crossing to Flpe transgenic mice.