B6.129-Tnfrsf18^tm1Ppp/CptJ

Stock number: 030648
Product name: GITR- (GITR KO)
Research areas: Cancer Research, Cell Biology Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools

Description

The GITR knock-out allele (GITR-) has exons 1-5 of the glucocorticoid-induced tumor necrosis factor receptor locus (Tnfrsf18) replaced with a reverse-oriented neo cassette. These mice may be useful in studying innate and adaptive immunity, as well as the receptor-ligand (GITR-GITRL) association with human disease or as combinatorial immunotherapy targets for studying solid tumor microenvironment.

Detailed description

The glucocorticoid-induced tumor necrosis factor receptor (GITR; encoded by Tnfrsf18) is a member of the TNF-receptor superfamily that functions to provide co-stimulatory signals essential for innate and adaptive immunity (regulates the function of both T cells and antigen-presenting cells [APCs]). This receptor is expressed in naive T cells (expression increases with activation), B cells and natural killer cells (NKs). Receptor-ligand (GITR-GITRL) binding leads to NFκB pathway induction, which subsequently promotes differentiation/expansion of CD4⁺ and CD8⁺ T cells, as well as maturation of thymic T regulatory cells (Tregs). GITR-GITRL defects are linked to human disease (including celiac disease and Crohn's disease), and this receptor-ligand are combinatorial immunotherapy targets for studying solid tumor microenvironment.

The GITR knock-out allele has exons 1-5 replaced with a reverse-oriented neo cassette. Homozygotes (GITR-/-) are viable and fertile, with flow cytometric analysis of T lymphocytes showing absence of endogenous protein. Relative to wild-type mice, homozygotes exhibit no significant differences in the weight or cellularity of lymphoid organs, with normal T lymphocyte subpopulations detected in spleen and lymph nodes.


GITR-/- mice are useful for studying how GITR engagement enhances Treg proliferation both in vivo and in vitro [Liao et al. 2010 Int Immunol. 22:259].
Furthermore, in an induced colitis protocol (injection of CD4⁺CD45RB^hi T cells), GITR-/- Rag1-/- recipients developed an aggravated chronic enterocolitis whereas Rag1-/- recipients did not. Because that phenotype resulted from an imbalance of colitogenic Th1 cells and Treg cells (independent of GITR-GITRL interaction), it suggests that GITR functions in dendritic cell and monocyte development [Liao et al. 2012 Gastroenterology 142:582].

Development

The GITR knock-out allele (GITR-) was created in the laboratory of Dr. Pier Paolo Pandolfi (while at Memorial Sloan-Kettering Cancer Center). A targeting vector was designed to replace ~600 bp of the promoter region, exons 1-5 and ~1.2 kbp of 3' sequences of the tumor necrosis factor receptor superfamily, member 18 locus (Tnfrsf18 ; GITR) on chromosome 4 with a reverse-oriented neomycin-resistance cassette. The construct was electroporated into 129S4/SvJaeJ-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts, and chimeric males were bred with C57BL/6 females for germline transmission. In 2004, Dr. Pandolfi sent GITR knock-out mice (black coat color) on a C57BL/6;129 genetic background to Dr. Cox Terhorst (Beth Israel Deaconess Medical Center / Harvard Medical School). There, Dr. Terhorst backcrossed them with C57BL/6J mice for ten generations prior to sending males with black coat color to The Jackson Laboratory Repository in 2017. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).
Of note, the donating investigator reports that, at least once during backcrossing, a GITR- female was bred to a C57BL/6J inbred male (thus the Y chromosome of the congenic strain is of C57BL/6J origin).

Allele

Symbol: Tnfrsf18^tm1Ppp
Name: targeted mutation 1, Pier Paolo Pandolfi
MGI accession ID: MGI:2676557
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: GITR^-; GITR-KO
Marker symbol: Tnfrsf18
Marker name: tumor necrosis factor receptor superfamily, member 18
Marker synonyms: AITR; CD357; ENERGEN; Gitr; GITR-D
Chromosome: 4
Strain of origin: 129S4/SvJae
Molecular note: Exons 1 through 5 were replaced with a neomycin selection cassette inserted by homologous recombination. The absence of normal protein was verified by flow cytometric analysis of T lymphocytes obtained from homozygous mutant mice.