C.129X1-Il4ra^tm3.1Tch/J

Stock number: 012709
Strain synonyms: C.129.Il4ra<F709>
Research areas: Cell Biology Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools

Description

These Il4ra^F709 mutant mice harbor a Y709F polymorphism within the canonical immunoreceptor tyrosine-based inhibitory motif (ITIM) sequence near the carboxyl-terminus of the protein. This Y709F polymorphism prevents ITIM phosphorylation and disables the binding of regulatory phosphatases. These Il4ra^F709 mutant mice may be useful in immunological studies of mitogenic signal transduction, specifically antigen-specific antibody responses, allergic airway inflammation, atopy, asthma, and food allergy research.

Detailed description

Mice homozygous for this Il4ra^F709 (IL-4Rα Y709F) polymorphic allele are viable and fertile. The mutation introduces a tyrosine to phenylalanine amino acid substitution at codon 709 (Y709F) within the canonical immunoreceptor tyrosine-based inhibitory motif (ITIM) sequence near the carboxyl-terminus of the protein. This Y709F polymorphism prevents ITIM phosphorylation and inhibit the binding of regulatory phosphatases (including Src homology 2 domain-containing protein tyrosine phosphatase 1 [SHP-1]), resulting in enhanced receptor signaling. Allele-specific PCR verifies the Y709 to F709 codon substitution. Homozygous mice exhibit enhanced phosphorylation of signal transducer and activator of transcription 6 (STAT6) in B cells following IL-4 treatment, and increased serum concentrations of total IgE and ovalbumin (OVA)-specific IgE after immunization with OVA/alum. Il4ra^F709/F709 mice have increased allergic airway inflammation (peribronchial and perivascular inflammation, goblet cells and eosinophil accumulation) and airway hyperresponsiveness in response to allergen sensitization and challenge.

Both untreated and OVA-challenged homozygous mice exhibit upregulated expression of a number of STAT6-responsive genes involved in allergic airway inflammation. The Y709F substitution results in increased IL-4 production after Th2 polarization (Th2 bias) and enhanced alternative macrophage activiation by IL-13 in vivo. The Il4ra^F709/F709 mice are highly susceptible to oral sensitization to OVA, even in the absence of adjuvants, and sensitized mice respond to oral challenge with anaphylaxis. These Il4ra^F709 mutant mice may be useful in immunological studies of mitogenic signal transduction, specifically antigen-specific antibody responses, allergic airway inflammation, atopy, asthma, and food allergy research.

Development

Two base pair substitutions (A->T and C->T at basepair 2362 and 2363, respectively) were introduced into the murine Il4ra cDNA using site-directed mutagenesis. These mutations result in a single amino acid substitution of tyrosine to phenylalanine at codon 709 (Y709F) within the canonical immunoreceptor tyrosine-based inhibitory motif (ITIM) sequence near the carboxyl-terminus of the protein. A targeting vector that included these two mutations and a loxP-flanked neo cassette inserted into intron 11 was electroporated into 129X1/SvJ-derived RW4 embryonic stem (ES) cells. Correctly targeted ES cells were transiently transfected with a cre-expressing vector to remove the neo selection cassette (leaving a single loxP site in intron 11) and then injected into recipient blastocysts. The resulting chimeric males were crossed to BALB/cAnNTac females. Heterozygotes were bred to BALB/cAnNTac for at least 10 generations prior to sending to The Jackson Laboratory Repository. Upon arrival, mice were bred to BALB/cByJ (Stock No. 001026) for at least one generation to establish the colony.

Allele

Symbol: Il4ra^tm3.1Tch
Name: targeted mutation 3.1, Talal A Chatila
MGI accession ID: MGI:4455123
Generation method: Targeted
Marker symbol: Il4ra
Marker name: interleukin 4 receptor, alpha
Chromosome: 7
Strain of origin: 129X1/SvJ
Molecular note: Two base pair substitutions (A->T and C->T at basepair 2362 and 2363, respectively) were introduced into the murine Il4ra cDNA using site-directed mutagenesis. These mutations result in a single amino acid substitution of tyrosine to phenylalanine at codon 709 (Y709F) within the canonical immunoreceptor tyrosine-based inhibitory motif (ITIM) sequence near the carboxyl-terminus of the protein. The targeting vector included these two mutations and a loxP-flanked neo cassette inserted into intron 11. Cre mdiated recombination removed the neo cassette.