C;129S4-Rag2^tm1.1Flv Csf1^tm1(CSF1)Flv Csf2/Il3^{tm1.1(CSF2,IL3)Flv} Thpo^{tm1.1(TPO)Flv} Il2rg^tm1.1Flv Tg(SIRPA)1Flv/J

Stock number: 017712
Product name: MISTRG
Research areas: Cancer Research, Developmental Biology Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools, Virology Research

Description

This strain has been discontinued. Please search the JAX Mice database for other strains which may be suitable for your studies or contact Technical Support for assistance.

Depending upon the experiment, the following may be considered for replacement strain(s):
BALB/c;129 Rag2^-;γc^- (Stock No. 014593)
BALB/c;129 Rag2^-;γc^-;TPO^h (Stock No. 014594)
BALB/c;129 Rag2^-;γc^-;IL-3/GM-CSF^h (Stock No. 014595)
BALB/c;129 Rag2^-;γc^-;hSIRPA^tg (Stock No. 017707)
BALB/c;129 Rag2^-;γc^-;CSF1^h (Stock No. 017708)

Detailed description

MISTRG are Rag2-deficient, Il2rg-deficient mice with human versions of four cytokines important for innate immune cell development (M-CSF^h;IL-3/GM-CSF^h;hSIRPA^tg;TPO^h;Rag2^-;γc^-). Because the human cytokines support the development and function of monocytes, macrophages and NK cells derived from liver or adult CD34⁺ progenitor cells injected into the mice, MISTRG mice are highly permissive for human hematopoiesis and enable the full recapitulation of human myeloid development and function in the mouse. This humanized mouse model may be used to model the human immune system in scenarios of health and pathology, such as human cell engraftment and patient-derived tumor xenografts (PDX).

Compared to MITRG mice (Stock No. 017711), MISTRG mice also have a human SIRPα-encoding BAC transgene. SIRPα binds to CD47 and the resulting signal suppresses phagocytosis of CD47-expressing cells. Because human CD47 constitutively expressed on human cells binds efficiently to the mouse BAC transgene-encoded human SIRPα, this transgene enables mouse phagocytes to tolerate and not engulf engrafted human cells.

The donating investigator reports that MISTRG females homozygous for the five targeted mutations and hemizygous for the human SIRPα BAC transgene are viable and fertile, but have impaired breeding performance. Females homozygous for the five targeted mutations and without the human SIRPα BAC transgene (i.e., MITRG homozygous females [Stock No. 017711]) are viable and fertile with normal fertility at least until 6 months of age. MISTRG males homozygous for the four somatic targeted mutations, hemizygous for the X-linked γc^- mutation and hemizygous or homozygous for the human SIRPα BAC transgene are viable and fertile with normal fertility at least until 6 months of age. Please see the "Technical Support" tab for specific "Breeding Considerations".

Using MITRG and MISTRG mice for human hematopoietic stem and progenitor cell engraftment as described in Rongvaux et al. 2014 Nat Biotechnol 32:364, the donating investigator additionally reports that ~80% of the mice reach ≥10% engraftment (hCD45+ cells in the blood) 8 weeks after injection. Irradiation dose from 0 to 2x200 cGy can be used. With 0 cGy, only 50% of the mice are highly engrafted in our experiments, but the mice are healthier. With higher doses, pathology can appear due to irradiation and lack of human-to-mouse phagocytic tolerance.

Development

MISTRG mice harbor three humanized knock-in alleles (M-CSF^h, IL-3/GM-CSF^h and TPO^h), the human SIRPa BAC transgene (hSIRPA^tg) and two knockout alleles (Rag2^- and γc^-); all designed by Dr. Richard A. Flavell (Yale University School of Medicine, HHMI).

MISTRG mice are MITRG animals additionally harboring the human SIRPa BAC transgene (hSIRPA^tg). Creation of the M-CSF^h, IL-3/GM-CSF^h, TPO^h, Rag2^- and γc^- alleles are as described for MITRG mice (Stock No. 017711).

To create the hSIRPa BAC transgene (Tg(SIRPA)1Flv or hSIRPA^tg), the bacterial artificial chromosome RP1179H23 (accession number A6083837) containing the entire human signal-regulatory protein alpha locus (SIRPA; corresponding to variant 2) was obtained. This BAC also has ~51 kbp 5prime flanking DNA and ~78 kbp 3prime flanking DNA. A loxP-flanked hUbp-hygromycin cassette (small bacterial Em7 promoter/human ubiquitin C promoter::hygromycin::PGK-polyA) was inserted into intron 1 via homologous recombination/BAC recombineering. The resulting ~177 kbp hSIRPa BAC transgene was injected into (BALB/cAnNTac x 129S4/SvJae)-derived V17.2 embryonic stem (ES) cells already harboring the Rag2^- and γc^- targeted mutations (see Stock No. 014593). Correctly re-targeted ES cells were identified and used to generate triple mutant mice. These triple mutant mice (Rag2^-;γc^-;hSIRPA^tg) on a mixed BALB/c;129 genetic background are described and available from The Jackson Laboratory as Stock No. 017707.

To generate the MISTRG mice, Dr. Flavell bred BALB/c;129 Rag2^-;γc^-;hSIRPA^tg mice with MITRG animals on a mixed BALB/c;129 genetic background (Stock No. 017711). The resulting MISTRG mice were maintained on a mixed BALB/c;129 genetic background prior to sending to The Jackson Laboratory in 2015 as Stock No. 017712.

Allele

Symbol: Rag2^tm1.1Flv
Name: targeted mutation 1.1, Richard A Flavell
MGI accession ID: MGI:4887836
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Rag2
Marker name: recombination activating gene 2
Chromosome: 2
Strain of origin: BALB/cAnNTac x 129S4/SvJae
Molecular note: A floxed PGK-neomycin cassette replaced the coding region. Cre-mediated recombination removed the neo cassette.
General note: Originally generated in conjunction with Il2rg^tm1.1Flv.

Allele

Symbol: Csf2/Il3^{tm1.1(CSF2,IL3)Flv}
Name: targeted mutation 1.1, Richard A Flavell
MGI accession ID: MGI:4887879
Generation method: Targeted
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Csf2
Marker name: colony stimulating factor 2 (granulocyte-macrophage)
Chromosome: 11
Strain of origin: BALB/cAnNTac x 129S4/SvJae
Expressed genes: CSF2,colony stimulating factor 2,human; IL3,interleukin 3,human
Molecular note: The coding region of Il3 through Csf2 was replaced with the corresponding human sequence. The human Il3 remains under the control of the mouse promoter while expression of Csf2 is controlled by the human promoter. Cre-mediated recombination removed the selection cassettes.
General note: Originally generated in ES cells containing Il2rg^tm1.1Flv and Rag2^tm1.1Flv.

Allele

Symbol: Il2rg^tm1.1Flv
Name: targeted mutation 1.1, Richard A Flavell
MGI accession ID: MGI:4887837
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Il2rg
Marker name: interleukin 2 receptor, gamma chain
Chromosome: X
Strain of origin: BALB/cAnNTac x 129S4/SvJae
Molecular note: A floxed human ubiquitin promoter-driven hygromycin cassette replaced the coding region. Cre-mediated recombination removed the hygro cassette.
General note: Originally generated in conjunction with Rag2^tm1.1Flv.

Allele

Symbol: Thpo^{tm1.1(TPO)Flv}
Name: targeted mutation 1.1, Richard A Flavell
MGI accession ID: MGI:4887867
Generation method: Targeted
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Thpo
Marker name: thrombopoietin
Chromosome: 16
Strain of origin: BALB/cAnNTac x 129S4/SvJae
Expressed genes: TPO,thyroid peroxidase,human
Molecular note: The coding region was replaced with the corresponding human sequence. Cre-mediated recombination removed the neo cassette.
General note: Originally generated in ES cells containing Il2rg^tm1.1Flv and Rag2^tm1.1Flv.

Allele

Symbol: Tg(SIRPA)1Flv
Name: transgene insertion 1, Richard A Flavell
MGI accession ID: MGI:5300383
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(SIRPA)1Flv
Marker name: transgene insertion 1, Richard A Flavell
Chromosome: UN
Strain of origin: BALB/cAnNTac x 129S4/SvJae
Expressed genes: SIRPA,signal regulatory protein alpha,human
Molecular note: The transgene contains a BAC encoding the entire 45 kb human SIRPA gene along with about 51 kb of 5' flanking DNA and 78 kb 3' flanking sequence. Line 1 was generated.
General note: Previously targeted V17 ES cells carrying Rag2^tm1.1Flv and Il2rg^tm1.1Flv were used to generate the transgene.

Allele

Symbol: Csf1^tm1(CSF1)Flv
Name: targeted mutation 1, Richard A Flavell
MGI accession ID: MGI:5616641
Generation method: Targeted
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Csf1
Marker name: colony stimulating factor 1 (macrophage)
Chromosome: 3
Strain of origin: (BALB/cJ x 129S4/SvJae)F1
Expressed genes: CSF1,colony stimulating factor 1,human
Molecular note: The mouse open reading frame (exon 2 through 9) was replaced with the human gene from BAC RPCI-11, clone 101M23.
General note: The version of this allele that does not contain the neomycin selection cassette, Csf1^{tm1.1(CSF1)Flv}, has been analyzed.