C;129S4-Rag2^tm1.1Flv Csf1^tm1(CSF1)Flv Il2rg^tm1.1Flv/J

Stock number: 017708
Product name: human M-CSF knockin
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

These humanized immunodeficient mice express human mCSF (CSF1) on a Rag2/Il2rg deficient background, significantly increasing their ability to engraft and maintain human hematopoietic cells.

Detailed description

Csf1 (colony stimulating factor 1 (macrophage)) is a cytokine that plays several physiological roles, among them the promotion of myeloid cell differentiation. CSF1 is believed to interact with hematopoietic stem cells to regulate the maturation, survival, adhesion and motility of macrophages.

Human mCSF (CSF1) replaces expression of mouse Csf1 in these Rag2/Il2rg knockout mice lacking T, B, and NK cells (see Stock No. 014593). Animals faithfully express a functional human CSF1 protein that is recognized by the mouse system both qualitatively and quantitatively. Unlike Csf1^op homozygous mice (Stock No. 000231), these animals exhibit normal teeth and bone properties as well as normal bone marrow cell content, myeloid cell frequencies in the bone marrow, spleen, and peripheral blood, and macrophage frequencies in the bone marrow and spleen.

Human CSF1 significantly increases the ability of the mice to engraft and maintain human hematopoietic cells. Intra-hepatic transfer of human fetal liver-derived hematopoietic stem and progenitor cells (CD34⁺) to newborn mice results in more efficient differentiation and enhanced frequencies of human monocytes/macrophages in bone marrow, spleen, peripheral blood, lungs, liver and the peritoneal cavity. Significant proportions of human CD14+CD33+ cells are observed at 16-20 weeks.

Development

MRG mice harbor the M-CSF^h humanized knock-in allele and two knockout alleles (Rag2^- and γc^-), all designed by Dr. Richard A. Flavell (Yale University School of Medicine, HHMI).

The Rag2^- (Rag2^tm1.1Flv) and γc^- (Il2rg^tm1.1Flv) knockout alleles were created in (BALB/cAnNTac x 129S4/SvJae)-derived V17.2 embryonic stem (ES) cells. The recombination activating gene 2 (Rag2) coding region on chromosome 2 is replaced with a loxP-flanked PGK-neo cassette. The interleukin 2 receptor gamma chain (Il2rg) coding region on chromosome X is replaced with a loxP-flanked hUbp-hygro cassette. Correctly targeted ES cells were transiently transfected with a cre plasmid to delete the floxed cassettes. The resulting BALB/c;129 Rag2^-;γc^- ES cells were used for electroporation of the M-CSF^h targeting vector described below. Rag2^-;γc^- mice on a mixed BALB/c;129 genetic background are described and available from The Jackson Laboratory as Stock No. 014593.

The M-CSF^h humanized knock-in allele (Csf1^tm1(CSF1)Flv or CSF1^h) replaces almost all the macrophage colony stimulating factor (Csf1) coding region on chromosome 11 with a 17.5 kbp human CSF1 sequence (exon 2 to 633nt downstream of noncoding exon 9), followed by a floxed hUbp-neo cassette. The Csf1 promoter and 5prime UTR are mouse origin. The M-CSF^h targeting vector was electroporated into BALB/c;129 Rag2^-;γc^- ES cells described above. The resulting triple mutant mice (Rag2^-;γc^-;CSF1^h) on a mixed BALB/c;129 genetic background are available from The Jackson Laboratory as Stock No. 017708. The CSF^h allele in these mice still has the floxed hUbp-neo cassette.

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: 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: 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.