STOCK Tg(Cd3d-Insr*)1Mcin/J

Stock number: 035908
Product name: CD3-3×FLAG-mIR/MFM, BL/6-CD3FLAGmIR, CD3FLAGmIR/mfm

Research areas: Diabetes and Obesity Research, Immunology, Inflammation and Autoimmunity Research

Description

CD3-3xFLAG-mIR/MFM mice express flag-tagged mouse insulin receptor (Insr) cDNA from the mouse Cd3d (CD3 antigen, delta polypeptide) promoter/enhancer. This enables INSR expression on T cells. Transgenic T cells migrate to the pancreas where they cause insulitis, but do not cause hyperglycemia/diabetes on this C57BL/6 genetic background.

Detailed description

Type 1 diabetes mellitus (T1D) is an autoimmune disease characterized by insulitis and T cell-mediated destruction of pancreatic islet beta cells. It has been shown that cells with a high density of insulin receptor (INSR) can chemotax toward insulin.

CD3-3×FLAG-mIR/MFM (CD3FLAGmIR/mfm) mice express flag-tagged mouse insulin receptor (Insr) cDNA from the mouse Cd3d (CD3 antigen, delta polypeptide) promoter/enhancer, enabling transgene expression on the surface of T cells. Detectable 3×FLAG protein is expressed on T-lymphocytes found in peripheral blood and spleen.

Transgenic T cells migrate to the pancreas of homozygous mice where they cause insulitis by about 15 weeks of age in males. Females reportedly develop the phenotype 5-10 weeks later. Beta cell functionality is affected, causing metabolic abnormalities. Islets are enlarged and disorganized. Features of the phenotype can be adoptively transferred to Rag1 knock-out mice 4-5 weeks post transfer of transgenic splenocytes.

On this C57BL/6 genetic background, mice do not spontaneously develop diabetes/hyperglycemia.

Development

CD3-3xFLAG-mIR/MFM mice express a 3xFLAG-mIR transgene insert which encodes a full-length mouse insulin receptor protein (INSR) cDNA containing an N-terminal 3xFLAG (DYKDDDDK) tagged α-subunit and full length β-subunit as seen in the native mouse Insr gene. The endogenous signal peptide coding sequence was deleted and replaced with a pre-protrypsin (PPT) signal peptide. The PPT-3xFLAGmIR transgene was placed downstream of the mouse Cd3d enhancer and promoter construct to elicit T-lymphocyte directed transgene over-expression. A human growth hormone (hGH) poly A signal enhances mRNA stability. The transgenic vector was introduced to C57BL/6NTac embryos. Mice were subsequently intercrossed by the donating laboratory (see SNP note below). The transgenic copy number and insert site are not known (December, 2020).

In 2021, 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. Three of the 43 markers throughout the genome were segregating with an unknown source. Also, two 4 of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. The rd8 recessive mutation associated with retinal degeneration on Chromosome 1 within the Crb1 locus were determined to be C57BL/6J-derived.These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed genetic background.

Allele

Symbol: Tg(Cd3d-Insr*)1Mcin
Name: transgene insertion 1, Marcia McInerney
MGI accession ID: MGI:6478197
Generation method: Transgenic
Attributes: Inserted expressed sequence; Epitope tag
Synonyms: CD3-3×FLAG-mIR/MFM
Marker symbol: Tg(Cd3d-Insr*)1Mcin
Marker name: transgene insertion 1, Marcia McInerney
Chromosome: UN
Strain of origin: C57BL/6NTac
Molecular note: The transgene insert encodes a full-length mouse insulin receptor protein cDNA containing an N-terminal 3xFLAG (DYKDDDDK) tagged alpha-subunit and full length beta-subunit as seen in the native mouse Insr gene. The endogenous signal peptide coding sequence was deleted and replaced with a pre-protrypsin (PPT) signal peptide. Thetransgene is placed downstream of the mouse Cd3d enhancer and promoter construct to elicit T-lymphocyte directed transgene over-expression. A human growth hormone (hGH) poly A signal enhances mRNA stability