B6.129X1-Cd28^tm2.1Jmg/Mmjax

Stock number: 012305
Product name: CD28-Y170F
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

These mice carry a mutant allele with a phenylalanine substitution for the tyrosine at position 170 in exon 4; homozygotes have IL-2 production and secretion similar to wildtype controls. This mutant mouse strain may be useful in studies of humoral immune response and T cell proliferation.

Detailed description

Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. These mice carry a mutant allele with a phenylalanine substitution for the tyrosine at position 170 in exon 4 (CD2- Y170F), which encodes proximal tyrosine-based binding motif. The substitution was confirmed by direct sequencing and RT-PCR. Mutant protein expression levels on thymocytes and peripheral T cells are similar to wildtype protein levels in control mice, as assayed by flow cytometry. Homozygotes have IL-2 production and secretion similar to wildtype controls. This mutant mouse strain may be useful in studies of humoral immune response and T cell proliferation.

Development

A targeting vector containing a floxed neo cassette was used to insert a phenylalanine substitution for the tyrosine at position 170 in exon 4. The construct was electroporated into 129X1/SvJ derived RW-4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. The resulting chimeric animals were crossed to a transgenic EllA-cre strain on the C57BL/6 background to remove the floxed neo selection cassette. The mice were then backcrossed to C57BL/6 for 10 generations. Upon arrival at the MMRRC at The Jackson Laboratory, the mice were crossed to C57BL/6J once to establish the colony.

Allele

Symbol: Cd28^tm2.1Jmg
Name: targeted mutation 2.1, Jonathan M Green
MGI accession ID: MGI:3850854
Generation method: Targeted
Attributes: Not Specified
Marker symbol: Cd28
Marker name: CD28 antigen
Chromosome: 1
Strain of origin: 129X1/SvJ
Molecular note: A TAC to TTC mutation was created in exon 4 to substitute phenylalanine for tyrosine at position 170 (Y170F). A floxed neomycin cassette was inserted upstream of the exon and was subsequently removed by cre-mediated recombination. Expression of the mutant allele in splenocytes and thymocytes was similar to endogenous levels as determined by flow cytometry analysis. This mutation disrupts the motif responsible for interaction with the p85 subunit of PI3-kinase.