B6(129S4)-Ncf2^{tm1c(EUCOMM)Wtsi}/DinJ

Stock number: 037260
Product name: Ncf2^fl
Research areas: Cancer Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

Ncf2^fl/fl floxed mice have loxP sites flanking exon 3 of the neutrophil cytosolic factor 2 gene. These mice may be suitable for use in studies related to chronic granulomatous disease and reactive oxygen species (ROS) and their roles in host defense and immunoregulation.

Detailed description

Ncf2^fl/fl mice have exon 3 of the neutrophil cytosolic factor 2 (Ncf2) gene floxed. The Ncf2 gene encodes the p67^phox (or NOXA2) subunit of the multi-protein NADPH oxidase complex found primarily in myeloid cells including neutrophils, monocytes, macrophages, eosinophils, and dendritic cells, as well as B-lymphocytes. NADPH oxidase generates superoxide, the precursor to reactive oxygen species (ROS) which plays essential roles in host defense and immunoregulation. Inactivating mutations in this gene are associated with chronic granulomatous disease, and hypomorphic variants of Ncf2 are associated with systemic lupus erythematosus (SLE) and other autoimmune disorders. Ncf2^fl/fl homozygous mice are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have coding exon 3 deleted in the Cre-expressing tissues.

When bred to LysMcre mice (Stock No. 004781), expressing nuclear-localized Cre recombinase in myeloid cell lineages, 95% of alveolar macrophages (AM) or resident peritoneal macrophages (RPM) in the resulting Ncf2^LysMCre mice lack NOX2 enzyme activity, with NCF2 expression only partially reduced in neutrophils. At 12 weeks of age, these mice show increased total leukocytes, neutrophils and pro-inflammatory cytokines in bronchoalveolar lavage fluid and a population of CD11c^highSiglec F^highCD11b^high AM which persist after one year of age, with no development of focal alveolar infiltrates. They also exhibit enhanced lung inflammation following insults.

Development

The L1L2_Bact_P cassette was inserted at a position on Chromosome 1 upstream of coding exon 3 of the neutrophil cytosolic factor 2 (Ncf2) gene. The cassette is composed of a FRT site, a β-galactosidase (lacZ) sequence, a loxP site, and a neomycin resistance (neo) cassette, followed by a second FRT site and a second loxP site. A third loxP site was inserted downstream of coding exon 3. The mutation was generated in C57BL/6N-derived JM8.N4 embryonic stem (ES) cells, and correctly targeted ES cells of clone EPD0240_5_F04 were injected into blastocysts. The resulting chimeric mice were bred to C57BL/6J mice and then subsequently to ROSA26-Flpe mice (Stock No. 009086) to remove the FRT-flanked region containing the lacZ and neo cassette sequences. Resulting Ncf2^fl/fl mice were bred to C57BL/6J mice to remove the Flp recombinase. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Ncf2^{tm1c(EUCOMM)Wtsi}
Name: targeted mutation 1c, Wellcome Trust Sanger Institute
MGI accession ID: MGI:6149902
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed)
Marker symbol: Ncf2
Marker name: neutrophil cytosolic factor 2
Chromosome: 1
Strain of origin: C57BL/6N
Molecular note: Flp-mediated excision of the parental Ncf2^{tm1a(EUCOMM)Wtsi} allele resulted in the removal of the promoter-driven neomycin selection cassette and the inserted lacZ reporter sequence, leaving behind the loxP-flanked critical exon(s). Further information on targeting strategies used for this and other IKMC alleles can be found at http://www.informatics.jax.org/mgihome/nomen/IKMC_schematics.shtml.