NOD/ShiLtJ-Tg(Foxp3-HBEGF/EGFP)1Doi/J

Stock number: 028763
Product name: NOD.Foxp3^DTR
Research areas: Diabetes and Obesity Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

Foxp3^DTR mice express a DTR/EGFP fusion protein from Foxp3 promoter/enhancer regions on a BAC transgene. Regulatory T lymphocytes may be depleted by 80%-90% in lymphoid organs following injections of diptheria toxin. These mice may be useful for studying role of regulatory T cells in controlling the progression of autoimmune diabetes.

Detailed description

Mice hemizygous for the BAC Foxp3^DTR transgene are viable and fertile. These mice express a human heparin-binding EGF-like growth factor (HBEGF or DTR, diptheria toxin receptor) sequence fused to an enhanced green fluorescent protein (EGFP) directed by Foxp3 (forkhead box P3) promoter/enhancer regions on the BAC transgene. FOXP3 is a transcription factor necessary for the development and function of regulatory T (Treg) cells, which are required for suppression of self-reactive T cells and prevention of some autoimmune diseases. In these mice, EGFP expression is evident in FOXP3⁺ CD4⁺CD25⁺ Treg cells. Two consecutive daily injection of diptheria toxin (DT) specifically depletes 80%-90% of these cells in lymphoid organs such as the spleen, axillary lymph nodes (LN), and pancreatic LN. Three days after the last injection, Treg cell numbers recover to only 60% depletion. Pancreatic islets of the DT-injected mice show a strong immune infiltrate at day 12 after this treatment. In contrast, only mild infiltrates are evident at the same time point after injections every other day.

Foxp3^DTR were bred to NOD.Cg-Tg(TcraBDC2.5,TcrbBDC2.5)1Doi/DoiJ mice (Stock No. 004460) in order to study the direct role of FOXP3⁺ Treg ablation on islet infiltration during the progression of autoimmune diabetes. Histological changes in islet morphology are seen as early as 24 hours after DT-induction. Overt disease develops within 3 days as evident by the activation of natural killer (NK) cells within the insulitic lesion, and the induction of Ifnγ expression.

Development

Bacterial artificial chromosome (BAC) library (CHORI) was used to obtain a BAC containing the entire mouse Foxp3 (forkhead box P3) gene. This BAC was modified to insert a human heparin-binding EGF-like growth factor (HBEGF or DTR, diptheria toxin receptor) sequence fused to an enhanced green fluorescent protein (EGFP), with a stop codon, between the first and second codons of the Foxp3 open reading frame. This modified BAC was microinjected into fertilized NODShiLt/J oocytes. A Foxp3^DTR founder line was established and then subsequently maintained by breeding transgenic mice with NODShiLt/J inbred mice for at least ten generations. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize NODShiLt/J oocytes (Stock No. 001976).

Allele

Symbol: Tg(Foxp3-HBEGF/EGFP)1Doi
Name: transgene insertion 1, Christophe Benoist
MGI accession ID: MGI:5789576
Generation method: Transgenic
Attributes: Reporter; Inserted expressed sequence
Marker symbol: Tg(Foxp3-HBEGF/EGFP)1Doi
Marker name: transgene insertion 1, Christophe Benoist
Chromosome: UN
Strain of origin: NOD/ShiLtJ
Expressed genes: HBEGF,heparin binding EGF like growth factor,human; GFP,Green Fluorescent Protein,
Site of expression: The enhanced green fluorescent fusion protein (HBEGF/EGFP) is expressed in regulatory T cells.
Molecular note: A BAC containing Foxp3 was modified by inserting a human heparin-binding EGF-like growth factor (HBEGF or DTR, diptheria toxin receptor) sequence fused to an enhanced green fluorescent protein (EGFP) with a stop codon between the first and second codons of the Foxp3 open reading frame.