B6N.129-Nlrp3^tm2Hhf/J

Stock number: 017970
Product name: Nlrp3^L351PneoR
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

These Nlrp3^L351PneoR mice serve as a constitutive knockout of the Nlrp3 gene. In the presence of cre recombinase however, a transcript encoding a L351P mutation is produced. This line may be useful in studying the role of cryopyrin in the regulation of autoinflammatory diseases.

Detailed description

Nlrp3^L351PneoR mice contain a floxed neomycin cassette in intron 2 of the NLR family, pyrin domain containing 3 gene, Nlrp3, in opposite orientation to gene (neoR), abolishing gene expression. These mice also contain a point mutation in exon 3, which results in a missense mutation, L351P, corresponding to human amino acid 353. This mutation is commonly found in humans with familial cold autoinflammatory syndrome (FCAS). NLRP3 encodes the protein cryopyrin, which is a cytosolic nucleotide-binding domain and leucine-rich repeat containing (NLR) protein expressed in white blood cells and chondrocytes. Cryopyrin controls the formation of the inflammasome which regulates the immune system's response to injury, toxins, and infection by cleaving interleukin (IL)-1β. NLRP3 mutations are known to cause autoinflammatory diseases known as cryopyrin-associated periodic syndromes (CAPS) such as FCAS, Muckle-Wells syndrome (MWS), and neonatal onset multisystem inflammatory disease (NOMID). Homozygotes are viable and fertile and lack expression of Nlrp3 due to the presence of the neoR cassette. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have the floxed-neoR deleted in the cre-expressing tissues, allowing expression of the mutated gene.

For example, when bred to B6.129P2-Lyz2^tm1(cre)Ifo/J mice (Stock No. 004781), Nlrp3^L351PneoR expression in myeloid lineage cells results in 100% lethality by one day after birth.

When bred to B6.Cg-Tg(CAG-cre/Esr1*)5Amc/J mice (Stock No. 004682), bone marrow derived dendritic cells (DCs) spontaneously secrete high levels of IL-1β in response to cold (32 degrees) incubation.

Development

A targeting vector was designed to insert a loxP-flanked neomycin resistance (neo) cassette, in reverse orientation to the gene, into intron 2 of the NLR family, pyrin domain containing 3 gene, Nlrp3. A point mutation was introduced into exon 3 resulting in a missense mutation, L351P, corresponding to human amino acid 353. This mutation is commonly found in humans with cryopyrin-associated periodic syndromes (CAPS). The construct was electroporated into 129/SvJ-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and resulting chimeric mice were bred to C57BL/6NCrl mice for at least 10 generations to establish a colony. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6NJ inbred mice (Stock No. 005304) for at least one generation.

Allele

Symbol: Nlrp3^tm2Hhf
Name: targeted mutation 2, Hal M Hoffman
MGI accession ID: MGI:3850013
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Humanized sequence; No functional change
Marker symbol: Nlrp3
Marker name: NLR family, pyrin domain containing 3
Chromosome: 11
Strain of origin: 129/Sv
Molecular note: The leucine 353 to proline human mutation associated with familial cold autoinflammatory syndrome was produced in mice by changing the equivalent leucine at position 351 to a proline (L351P). A floxed neomycin cassette was inserted in the reverse orientation into intron 2, which is upstream of the point mutation in exon 3. Sequence analysis of transcripts isolated from heterozygote mice demonstrate the mutant allele is not expressed due to the presence of the neomycin cassette. In the presence of cre recombinase, the neomycin cassette is removed and the mutant allele is expressed.