NOD.Cg-Prkdc^scid Hprt^em1Mvw Il2rg^tm1Wjl/MvwJ

Stock number: 026222
Strain synonyms: NSG-Hprt^null
Research areas: Cancer Research, Cardiovascular Research, Developmental Biology Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools, Virology Research

Description

NSG-Hprt^null mice are NOD.scid.Il2Rγc^null ("NSG") animals with the Hprt^null knockout allele. The NSG model is permissive for xenograft/human tumor growth, with Hprt-deficiency allowing human tumors to be transplanted into culture and any mouse cells removed (via HAT selection).

Detailed description

NSG-Hprt^null mice are NOD.scid.Il2Rγc^null ("NSG"; Stock No. 005557) animals also harboring the Hprt^em1Mvw allele (Hprt^null). The Hprt^null mutation has as a frame shift and premature termination, resulting in function knockout. Hprt-deficiency causes hypoxanthine-aminopterin-thymidine (HAT)-inducible cell death, but renders the cell resistant to 6-thioguanine (6-TG) cytotoxicity.

NSG-Hprt^null females homozygous for all three mutations, and males that are homozygous for scid and hemizygous for the X-linked mutations Hprt^null and Il2Rγc^null, may be collectively referred to as homozygous NSG-Hprt^null mice.

These NSG-Hprt^null mice may be expected to have a similar phenotype as the NSG-Hprt^b-m3 model (Stock No. 012480) that has the Hprt^b-m3 knockout rather than the Hprt^em1Mvw knockout. The expected phenotype of NSG-Hprt^null mice is described below.
Although viable and fertile, homozygous NSG-Hprt^null mice are immunodeficient: they have no mature T cells or B cells, lack functional natural killer (NK) cells, have reduced numbers of lymphocytes and myeloid dendritic cells, and are deficient in cytokine signaling. The Hprt-deficiency results in biochemically defective stromal cells.
Like homozygous NSG mice, homozygous NSG-Hprt^null mice are designed to allow engraftment of human tissues and primary cancers, such as hematopoietic cancers (e.g., leukemia), melanoma, ER+ breast cancer xenografts, purified human CD4⁺ T cells (fractionated from human peripheral blood mononuclear cells [PBMC]), and other tissues. When human cancers are implanted in Hprt-deficient NSG mice, the mouse fibroblast and stromal cells replace the human stromal cells. Following tumor explantation into culture, any Hprt-deficient mouse cells can be eliminated by HAT selection; resulting in isolation of human cancer cells. Conversely, Hprt-deficient mouse cells can be enriched by 6-TG selection. These mice may be used to generate patient-specific low passage cell lines from primary cancers for use in chemosensitivity profiling and other applications.

Similar to other immunodeficient strains, maintaining homozygous NSG-Hprt^null mice in high health status (specific pathogen-free) vivaria promotes overall colony health. If homozygous NSG-Hprt^null animals are maintained in low health barrier rooms, the use of medicated water (e.g., sulfatrim/trimethoprim-sulfa or enrofloxacin/Baytril) is suggested to increase overall colony health.

View our Resources for the NSG mouse model, including discussion forum, immunodeficient model comparison, and categorized, up-to-date references.

Development

NSG-Hprt^null mice are NOD.scid.Il2Rγc^null ("NSG") animals with the Hprt^em1Mvw knockout allele (Hprt^null). NSG-Hprt^null mice harbor several mutations, as described below.

NSG mice are non-obese diabetic animals (NOD/ShiLtJ) harboring the spontaneous severe combined immunodeficiency mutation (Prkdc^scid) on chromosome 16 and the Il2Rγc^null mutation at ~101 Mbp on the X chromosome (Il2rg^tm1Wjl created by Dr. Warren J. Leonard [NIH]). NSG mice are described and available from The Jackson Laboratory Repository as Stock No. 005557.

The Hprt^em1Mvw knockout allele (Hprt^null) was created by Dr. Michael V. Wiles (The Jackson Laboratory) using CRISPR/Cas9 genome engineering in NSG mouse zygotes (Stock No. 005557). The hypoxanthine guanine phosphoribosyl transferase locus (Hprt) on the X chromosome (~53 Mbp) was targeted with a specific single guide RNA (sgRNA) to create an 18 bp deletion, resulting in a frame shift and premature termination. The founder mouse was bred to NSG mice, and the offspring were bred together to produce homozygous mice.

In 2014, Dr. Wiles sent NSG-Hprt^null triple mutant mice to The Jackson Laboratory Repository as Stock No. 026222. The colony is maintained by breeding females homozygous for all three mutations with males that are homozygous for scid and hemizygous for the X-linked mutations Hprt^null and Il2Rγc^null.

Allele

Symbol: Prkdc^scid
Name: severe combined immunodeficiency
MGI accession ID: MGI:1857113
Generation method: Spontaneous
Marker symbol: Prkdc
Marker name: protein kinase, DNA activated, catalytic polypeptide
Chromosome: 16
Strain of origin: C.BKa-Igh^b/Icr
Site of expression: T and B lymphocytes.
Molecular note: A T-to-A transversion point mutation at a position corresponding to codon 4046 (codon 4095 in transcript ENSMUST00000023352.8) created a premature stop codon (p.Y4046*).

Allele

Symbol: Il2rg^tm1Wjl
Name: targeted mutation 1, Warren J Leonard
MGI accession ID: MGI:1857455
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Il2rg
Marker name: interleukin 2 receptor, gamma chain
Chromosome: X
Strain of origin: 129S4/SvJae
Site of expression: Primarily lymphoid cells.
Molecular note: A neomycin resistance cassette replaced part of exon 3 and all of exons 4 - 8 of the gene, resulting in the loss of most of the extracellular domain and all of the transmembrane and cytoplasmic domains of the protein.

Allele

Symbol: Hprt^em1Mvw
Name: endonuclease-mediated mutation 1, Michael Wiles
MGI accession ID: MGI:5572799
Generation method: Endonuclease-mediated
Attributes: Null/Knockout
Marker symbol: Hprt
Marker name: hypoxanthine guanine phosphoribosyl transferase
Chromosome: X
Strain of origin: NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ
Molecular note: This allele was generated by injecting Cas9 RNA and a specific single guide RNA (sgRNA) to create an 18 bp deletion, resulting in a frame shift and premature termination.