NOD.Cg-Foxn1^em1Dvs Prkdc^scid Il2rg^tm1Wjl/J

Stock number: 026263
Product name: NSG-nude , NSG-Foxn1^null (line 25-5 ; del1)
Research areas: Cancer Research, Cardiovascular Research, Dermatology Research, Developmental Biology Research, Endocrine Deficiency Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools, Virology Research

Description

NSG-nude (or NSG-Foxn1^null) mice are NOD.scid.Il2Rγc^null ("NSG") animals with the Foxn1^null knockout allele. The NSG model is permissive for human xenografts, with Foxn1-deficiency (lack of thymus) allowing human stem cell-derived, thymic epithelial cell (TEC) precursors to reconstitute the only thymopoeitic effector population. NSG-nude mice are useful for studying the function of human TECs in disease models of type 1 diabetes, autoimmunity and transplantation.

Detailed description

NSG-nude (or NSG-Foxn1^null) mice are NOD.scid.Il2Rγc^null ("NSG"; Stock No. 005557) animals also harboring the Foxn1^em1Dvs allele (Foxn1^null). The Foxn1^null mutation has a 1 nucleotide deletion that causes a frame shift and premature truncation after an additional out-of-frame ~120 nucleotides - resulting in a 300 aa protein that is a functional knockout.

NSG-nude females homozygous for all three mutations, and males that are homozygous for Foxn1^null, homozygous for scid and hemizygous for the X-linked Il2Rγc^null, may be collectively referred to as homozygous NSG-nude mice.

Of note, homozygous NSG-nude males in The Jackson Laboratory Repository colony are subfertile and often non-productive breeders (January 2018). Furthermore, it is the experience of The Jackson Laboratory that breeding NSG-nude mice together as Foxn1^em1Dvs heterozygotes results in less than Mendelian expectations of Foxn1^em1Dvs homozygous pups.

These NSG-nude mice may be expected to combine the NSG phenotype (Stock No. 005557) with the Foxn1^nu spontaneous knockout phenotype (Stock No. 000819). The expected phenotype of NSG-nude mice is described below.
Homozygous NSG 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. Foxn1-deficient mice have no thymus (lack T cells and cell-mediated immunity) with functional-but-faulty hair growth follicles (hairless ["nude"] appearance). Foxn1-deficient females are poor mothers as they are unable to keep pups warm and have poor lactation.
Like homozygous NSG mice, homozygous NSG-nude mice are designed to robustly support engraftment human hematopoietic cells, human tissues and primary cancers: these include purified human CD4⁺ T cells (fractionated from human peripheral blood mononuclear cells [PBMC]), hematopoietic cancers (e.g., leukemia), melanoma, ER+ breast cancer xenografts, and other tissues. Foxn1-deficiency additionally allows human stem cell-derived, thymic epithelial cell (TEC) precursors to reconstitute the only thymopoietic effector population.

Similar to other immunodeficient strains, maintaining homozygous NSG-nude mice in high health status (specific pathogen-free) vivaria promotes overall colony health. If homozygous NSG-nude 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-nude (or NSG-Foxn1^null) mice are NOD.scid.Il2Rγc^null ("NSG") animals with the Foxn1^em1Dvs knockout allele (Foxn1^null). NSG-nude 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 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 Foxn1^em1Dvs knockout allele (Foxn1^null) was created by the Type 1 Diabetes Repository (Dr. David V. Serreze) at The Jackson Laboratory using CRISPR/Cas9 genome engineering in NSG mouse zygotes (Stock No. 005557). The forkhead box N1 locus (Foxn1) on chromosome 11 was targeted with a specific single guide RNA (sgRNA) to create a 1 nucleotide deletion (GGCcAACGCCG to GGC-AACGCCG) in exon 5 (encodes the N-terminal portion of the DNA binding domain). This 1 nucleotide deletion causes a frame shift and premature truncation after an additional out-of-frame ~120 nucleotides - resulting in a 300 aa protein. The founder mice were bred to NSG mice, and the offspring were bred together to produce homozygous mice.

In 2014, NSG-nude triple mutant mice were established at The Jackson Laboratory Repository as Stock No. 026263. The colony is maintained by breeding females heterozygous for Foxn1^null, homozygous for scid and homozygous for the X-linked Il2Rγc^null with males that are heterozygous for Foxn1^null, homozygous for scid and hemizygous for the X-linked 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: Foxn1^em1Dvs
Name: endonuclease-mediated mutation 1, David V Serreze
MGI accession ID: MGI:5882743
Generation method: Endonuclease-mediated
Attributes: Null/Knockout
Marker symbol: Foxn1
Marker name: forkhead box N1
Chromosome: 11
Strain of origin: NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ
Molecular note: CRISPR/cas9 endonuclease mediated genome editing is used to introduce a 1 nucleotide deletion (GGCcAACGCCG to GGC-AACGCCG) in exon 5 (encodes the N-terminal portion of the DNA binding domain). This 1 nucleotide deletion causes a frame shift and premature truncation after an additional out-of-frame ~120 nucleotides - resulting in a 300 aa protein.

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.