B6.129S-Rag1^tm1Mom Cd47^tm1Fpl Il2rg^tm1Wjl/SzJ

Stock number: 032088
Product name: BRAGG47
Research areas: Cancer Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools

Description

BRAGG47 are a triple knock-out mouse line lacking RAG1, CD47, and X-linked IL2RG - making them tolerant of xenotransplantation, resistant to graft versus host disease, and susceptible to HIV.

Detailed description

The phenotype described below reflects the characterization of B6.129S-Rag2^tm1Fwa Cd47^tm1Fpl Il2rg^tm1Wjl/J (Stock No. 025730) mice. Although expected to be the same, it should be noted that the phenotype of the BRAGG47 mice could vary from that described below. We will modify the strain description if necessary.

Triple knockout mice do not express the recombination activating gene 1 (Rag1), the CD47 antigen (CD47) gene, or the X-linked interleukin 2 receptor, gamma chain (Il2rg) gene and, therefore, contain no T cells, B cell, or Natural Killer (NK) cells. The disruption of the Il2rg gene prevents the development of thymomas and delays the onset of graft versus host disease (GVHD). Recognition of human CD47 by the murine signal-regulatory protein alpha (SIRPα) is required to suppress macrophage-mediated phagocytosis of transplanted human hematopoietic stem cells (HSCs). C57BL/6 mice express a form of the SIRPα receptor that does not recognize human CD47, leading to a lack of tolerization of xenotransplantation. Since phagocytes developed in a CD47-negative environment are tolerized to cells that do not express CD47, disruption of murine CD47 in this C57BL/6 model negates the requirement for CD47-SIRPa signaling and induces tolerance to transplanted human cells. These mice are viable and fertile.

Development

This strain was generated in three steps. First, mice from the B6.129S4-Il2rg^tm1Wjl/J (Stock No. 003174) and B6.129S7-Cd47^tm1Fpl/J (Stock No. 003173) colonies were interbred. Second, mice from B6.129S4-Il2rg^tm1Wjl/J (Stock No. 003174) and B6.129S7-Rag1^tm1Mom/J (Stock No. 002216) were interbred. Third, progeny from both matings were combined to generate females that are homozygous for the Rag1 KO, Cd47 KO and Il2rg KO alleles. Males are homozygous for the Rag1 KO and Cd47 KO alleles and hemizygous for the X-linked Il2rg KO allele.

Allele

Symbol: Rag1^tm1Mom
Name: targeted mutation 1, Peter Mombaerts
MGI accession ID: MGI:1857241
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: Rag-; Rag^1tm1Mom; RAG-1-; Rag1^-; RAG1^null; Rag-1KO
Marker symbol: Rag1
Marker name: recombination activating gene 1
Marker synonyms: RAG-1; RNF74
Chromosome: 2
Strain of origin: 129S7/SvEvBrd-Hprt1⁺
Site of expression: expression is seen in bone marrow derived cell lines.
Molecular note: A 1356 bp genomic fragment of the Rag1 gene, encoding the nuclear localization signal and the zinc-finger motif, was replaced by a neomycin cassette. A mutant transcript expressed from this allele was detected by Northern blot in bone marrow derived cell lines from homozygous mice.

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: Cd47^tm1Fpl
Name: targeted mutation 1, Frederik P Lindberg
MGI accession ID: MGI:1861955
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: CD47^-; IAP^-; Itgp^tm1Fpl
Marker symbol: Cd47
Marker name: CD47 antigen (Rh-related antigen, integrin-associated signal transducer)
Marker synonyms: 9130415E20Rik; B430305P08Rik; IAP; integrin-associated protein; Itgp; MER6; OA3
Chromosome: 16
Strain of origin: 129S7/SvEvBrd-Hprt1^b-m2
Molecular note: A neomycin resistance cassette was inserted into exon 2 of the gene, which encodes the signal peptide cleavage site and the IgV domain. Monoclonal antibodies recognizing the Ig domain failed to detect any CD47 antigen on the surface of erythrocytes, bone marrow cells, or other cells including peripheral blood leukocytes, splenocytes, and fibroblasts from homozygous mutant mice. In addition, no antigen was detected in mutant erythrocyte lysates with polyclonal antisera to the NH2 or COOH-termini.