D1.129P2(B6)-Fcer2a^tm1Kik/J

Stock number: 017795
Research areas: Immunology, Inflammation and Autoimmunity Research

Description

In this knockout strain a NEO cassette replaces exon 4 of the Fcer2a gene. These mice exhibit increased resistance to collagen-induced arthritis with delayed onset of symptoms. They may have applications in studies related to autoimmunity and inflammation.

Detailed description

The Fc low affinity IgE receptor is found on B cells, follicular dendritic cells, and a subset of T cells mediating IgE synthesis and regulation, IgE-dependent cytotoxicity, and B-cell activation and growth. These mice carry a targeted mutation of the Fcer2a (Fc receptor, IgE, low affinity II, alpha polypeptide) gene and have been backcrossed onto the autoimmune-susceptible DBA/1 background. Homozygotes are resistant to collagen-induced arthritis, with the few affected mutants developing mild arthritis. Time to onset of symptoms is delayed compared to controls. Four weeks after the collagen challenge up to 17% of the homozygous mice develop symptoms compared with 50-64% of the wildtype controls. However, incidence of disease in both mutant and wildtype mice is similar after 10 weeks. Both Anti-Collagen IgG antibodies and TNFalpha levels found in homozygous mice are similar to levels seen in controls. Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. During backcrossing, the Y chromosome may not have been fixed to the DBA/1 genetic background.

Development

A targeting vector containing a NEO cassette was used to disrupt exon 4. The construct was electroporated into 129P2/OlaHsd derived E14.1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were crossed to C57BL/6 mice, and then backcrossed to DBA/1 for 10 generations. Upon arrival at The Jackson Laboratory, the mice were crossed to DBA/1J (Stock No. 000670) at least once to establish the colony.

Allele

Symbol: Fcer2a^tm1Kik
Name: targeted mutation 1, Hitoshi Kikutani
MGI accession ID: MGI:3583003
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: CD23^-
Marker symbol: Fcer2a
Marker name: Fc receptor, IgE, low affinity II, alpha polypeptide
Marker synonyms: BLAST-2; CD23; CD23A; CLEC4J; FC epsilon RII; Fce2; FCErII; IGEBF; low-affinity IgE receptor; Ly-42
Chromosome: 8
Strain of origin: 129P2/OlaHsd
Molecular note: A neomycin resistance cassette was inserted into exon 4. Northern blot of mutant lymphocytes confirmed absence of transcript.