B6.Cg-Fcer1a^tm1Knt Tg(FCER1A)1Bhk/J

Stock number: 010506
Research areas: Immunology, Inflammation and Autoimmunity Research

Description

These double mutant mice express the human Fc fragment of IgE, high affinity I, receptor for; alpha polypeptide, (FCER1A), under the control of the human FCER1A promoter and carry the Fcer1a^tm1Knt targeted mutation. Mice that are hemizygous for the transgene and homozygous for the targeted mutation respond to experimental induction of anaphylaxis and are more sensitive to 2,4,6-tri-nitrobenzenesulfonic acid (TNBS)-induced colitis. These mutant mice exhibit increased levels of IL4 in the colon, enhanced intestinal permeability and modified fecal bacterial flora composition. This mutant mouse strain may be useful in studies of allergic response, anaphylaxis, hypersensitive immune response, and inflammatory bowel disease.

Detailed description

These double mutant mice express the human Fc fragment of IgE, high affinity I, receptor for; alpha polypeptide, (FCER1A), under the control of the human FCER1A promoter and carry the Fcer1a^tm1Knt targeted mutation. Mice that are hemizygous for the transgene and homozygous for the targeted mutation express a functioning chimeric receptor complex in which the human alpha-chain associates with the mouse beta- and gamma- chains. Transgene expression is detected on bone marrow derived cultured mast cells (BMMC), mast cells, basophils, monocytes, eosinophils, and epidermal Langerhans cells by FACS, hIgE binding and Western blot analysis and mimics both the human FCER1A expression and cell specificity pattern. The humanized receptor is estimated to be expressed approximately 3 to 5 fold higher than the endogenous mouse receptor. The double mutant mice respond to experimental induction of anaphylaxis and are more sensitive to 2,4,6-tri-nitrobenzenesulfonic acid (TNBS)-induced colitis. These mutant mice exhibit increased levels of IL4 in the colon, enhanced intestinal permeability and modified fecal bacterial flora composition. This mutant mouse strain may be useful in studies of allergic response, anaphylaxis, hypersensitive immune response, and inflammatory bowel disease.

Development

These double mutant mice were generated by crossing transgenic mice carrying the Tg(FCER1A)1Bhk transgene with Fcer1a^tm1Knt targeted mutant mice. The targeted mutant allele was created using a targeting vector containing neomycin resistance and herpes simplex virus thymidine kinase genes to disrupt exon 4, which encodes an immunoglobulin domain. The construct was electroporated into 129S2/SvPas derived D3 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were crossed to BALB/cJ mice, and then backcrossed to the same for 20 generations.
The transgenic strain was generated using a transgenic construct containing the entire human Fc fragment of IgE, high affinity I, receptor for; alpha polypeptide, (FCER1A), including 2.9kb of upstream sequence. The transgene was coinjected with a plasmid containing the hprt minigene. These constructs were transfected into ES65-154 (E14TG2a-165) embryonic stem (ES). ES cells containing the construct were injected into recipient C57BL/6 blastocysts to generate chimeric mice. The resulting male chimeric animals were bred to female mice carrying the Fcer1a^tm1Knt targeted mutation. The donating investigator reported that double mutant mice were then backcrossed to C57BL/6 (see SNP note below) for more than 8 generations before arriving at The Jackson Laboratory.

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 1 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: Tg(FCER1A)1Bhk
Name: transgene insertion 1, Beverly H Koller
MGI accession ID: MGI:3846551
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(FCER1A)1Bhk
Marker name: transgene insertion 1, Beverly H Koller
Chromosome: UN
Strain of origin: 129P2/OlaHsd
Expressed genes: FCER1A,Fc fragment of IgE receptor Ia,human
Molecular note: The transgenic construct contains the entire human Fc fragment of IgE, high affinity I, receptor for; alpha polypeptide, (FCER1A), including 2.9kb of upstream sequence. The transgene was coinjected with a plasmid containing the hprt minigene. These constructs were transfected into ES65-154 (E14TG2a-165) embryonic stem (ES).
General note: ES cells = ES65-154 (E14TG2a-165) cells

Allele

Symbol: Fcer1a^tm1Knt
Name: targeted mutation 1, Jean-Pierre Kinet
MGI accession ID: MGI:2383982
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Fcer1a
Marker name: Fc receptor, IgE, high affinity I, alpha polypeptide
Chromosome: 1
Strain of origin: 129
Molecular note: Exon 4, encoding an immunoglobulin domain, was disrupted by the insertion of a neomycin selection cassette. The absence of a functional encoded protein on the cell surface was determined by fluorescence activated cell sorting analysis of bone marrow mast cells obtained from homozygous mutant mice.
General note: ES cell line = D3 (129S2/SvPas) or E14TG2a (129P2/OlaHsd).