NOD.Cg-Idua^em1Osp Prkdc^scid Il2rg^tm1Wjl/J

Stock number: 035868
Product name: NSG-MPSI
Strain synonyms: NSG-IDUA^x, NSG-IDUA^X
Research areas: Cancer Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Mouse/Human Gene Homologs, Research Tools, Virology Research

Description

NSG-MPSI mice are NOD.scid.Il2Rγc^null ("NSG") animals with a CRISPR-made insertion of the W392X mutation in the endogenous mouse Idua gene, analogous to the human W402X mutation commonly observed in patients with the severe lysosomal storage disorder mucopolysaccharidosis type I (MPS I or Hurler syndrome). NSG-MPSI mice are designed to provide an improved environment for transplantation of human immune cells, and may be useful in studying genome-edited CD34+ hematopoietic stem and progenitor cells as a potential treatment for MPS I.

Detailed description

NSG-MPSI mice are NOD.scid.Il2Rγc^null ("NSG"; Stock No. 005557) animals also harboring the Idua^em1Osp knock-in allele (Idua^W392X or Idua^X) having a nonsense codon substitution of the tryptophan amino acid in position 392 of Idua exon 9 that results in a premature STOP. Idua^W392X is analogous to the human IDUA^W402X mutation commonly observed in patients with the severe lysosomal storage disorder mucopolysaccharidosis type I (MPS I or Hurler syndrome).

Females homozygous for all three mutations, and males that are homozygous for Idua^W392X, homozygous for scid and hemizygous for the X-linked Il2Rγc^null mutation, may be collectively referred to as NSG-MPSI mice.

Although viable, NSG-MPSI 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 NSG platform is permissive for xenograft/human hematopoietic stem cell engraftment.

The donating investigator reports that NSG-MPSI mice have no detectable IDUA enzyme activity in the brain, liver, and spleen, confirming a functionally null allele. Moreover, these mice accumulate glycosaminoglycans (GAGs) and the urinary excretion of GAGs increases progressively with age. NSG-MPSI mice exhibit progressive dysmorphism (broadening of face, flattening of the snout, and thickening of the paws), bone dysplasia, and visceral enlargement, though their average lifespan is equivalent to NSG controls.
Behaviorally, homozygous NSG-IDUA^X/X mice exhibit defects in spontaneous locomotion, long-term memory retention, and anxiety-like behaviors including: reduced locomotion and decreased exploratory behavior, shorter crossing times in the passive inhibitory avoidance task and deficits in the marble-burying task.

Maintenance Note: Similar to other immunodeficient strains, maintaining NSG-MPSI mice in high health status (specific pathogen-free) vivaria promotes overall colony health.

Development

NSG-MPSI mice are NOD.scid.Il2Rγc^null ("NSG") animals with the Idua^W392X knock-in allele. NSG-IDUA^xmice 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 NSG-MPSI mice (also called NSG-IDUA^X) were created in the laboratory of Dr. Natalia Gomez-Ospina (Stanford University) using CRISPR/Cas9 genome engineering in NSG mouse zygotes (from Stock No. 005557). Exon 9 of the iduronidase, alpha-L locus (Idua) on chromosome 5 was targeted with two specific single guide RNAs [Guide1 (5'-TTATAGATGGAGAACAACTC-3') cleaves 4 bases upstream and Guide3 (5'-GTTGGACAGCAATCATACAG-3') cleaves 44 bases downstream of the target site]. The plasmid was co-injected with Cas9 mRNA into NSG-derived zygotes and the resulting mice were screened for the presence of the Idua^W392X allele by PCR (see note on mutation and exon numbering below). One homozygous male was subsequently bred to an NSG female for germline transmission of the Idua^W392X allele and progeny were then intercrossed to generate homozygotes before mice were sent to The Jackson Laboratory in 2021. Upon arrival, sperm was frozen. To establish our live colony, an aliquot of frozen sperm was used to fertilize NSG oocytes.

Mutation and exon numbering note: The human IDUA^W402X nonsense mutation should correspond to mouse Idua^W401X. The original reference of this mutation as mouse Idua^W392X is likely an artifact associated with using mouse Methionine 10 as the start codon rather than mouse Methionine 1 (note the human IDUA canonical transcript has no Methionine in its first 100 aa other than the start codon). With respect to the mouse Idua canonical transcript [Idua-201; ENSMUST00000071650.13], the W401X mutation is in exon 10 (which is the 9th coding exon as no coding sequences are present in exon 1). [January 2023]

Allele

Symbol: Prkdc^scid
Name: severe combined immunodeficiency
MGI accession ID: MGI:1857113
Generation method: Spontaneous
Synonyms: scid
Marker symbol: Prkdc
Marker name: protein kinase, DNA activated, catalytic polypeptide
Marker synonyms: DNAPDcs; DNAPK; DNA-PK; DNAPKc; DNA-PKC; DNA-PKcs; DNPK1; DOXNPH; dxnph; HYRC; HYRC1; IMD26; p350; S473K; slip; XRCC7
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
Synonyms: [KO]gammac; CD132^-; gammac^-; gc^-; Il2rg^tm1Wjll; IL2Rgamma^null
Marker symbol: Il2rg
Marker name: interleukin 2 receptor, gamma chain
Marker synonyms: [g]c; Ab2-183; Cd132; CIDX; common cytokine receptor gamma chain; common gamma chain; gamma C receptor; gamma(c); gammaC; gc; IL-2RG; IMD4; P64; SCIDX; SCIDX1
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: Idua^em1Osp
Name: endonuclease-mediated mutation 1, Natalia Gomez-Ospina
MGI accession ID: MGI:6501945
Generation method: Endonuclease-mediated
Attributes: Humanized sequence
Synonyms: IDUA^X
Marker symbol: Idua
Marker name: iduronidase, alpha-L
Marker synonyms: IDA; MPS1; MPSI
Chromosome: 5
Strain of origin: NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ
Molecular note: CRISPR/cas9 genome editing is used to replace the tryptophan at position 392 with a nonsense codon, W392X (initially published as W329X), in exon 9 . W392X is analogous to the human W402X mutation associated with severe mucopolysaccharidosis type I (MPSI).