NOD.Cg-Tcra^tm1Mjo Tg(TcraG9C8)22Fsw/J

Stock number: 032569
Product name: A22Calpha-
Research areas: Diabetes and Obesity Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

A22Calpha^- mice, carrying a Tcra knock-out in addition to a Tcra transgene (derived from diabetogenic CD8 T-cell clone G9C8 sequence), were developed to look at the selection, activation and development of insulin-reactive T cells associated with type I diabetes.

Detailed description

G9C8 is a highly diabetogenic CD8 T-cell clone derived from NOD mice that is specific for low-avidity insulin peptide B15-23. Cells responsive to this antigen are among the earliest of pancreatic islet infiltrates.

These B2Calpha^- mice, carrying a Tcra knock-out (see Stock No. 004444) in addition to a Tcra chain transgenic allele derived from G9C8 sequence, were developed to look at the selection, activation and development of these insulin-reactive T cells. The mice have a restricted T cell repertoire.

Intercrosses with Tcra knock-out/Tcrb G9C8 transgenic mice (see Stock No. 032568) generate animals in which the CD8 T cells predominantly express the G9C8 insulin reactive TCR recognizing insulin B15‐23 peptide. Whilst the mice do not develop spontaneous diabetes, the cells can be activated to generate highly diabetogenic cytotoxic CD8 T cells.

This strain was used to demonstrate that autoimmune CD8 T-cells responding to a low-affinity insulin B-chain peptide escape from thymic negative selection and require activation in vivo to cause diabetes.

Development

Insulin-specific TCR transgenic mice were generated by isolating TCR genomic DNA from G9C8 cloned T-cells, which have previously been shown to have specific reactivity to amino acids 15–23 of the insulin B-chain. Tcra genomic DNA (Vα18S1 Jα18 Cα) was isolated and cloned into the pTαcass construct incorporating essential promoter and enhancer elements to enable expression of Tcra genes (PMID 7714342). The construct was linearized and injected into NOD/Caj ova. Crosses with NOD/Caj-backcrossed (N25+) TCR.Cα^- mice (Tcra^tm1Mjo allele found in Stock No. 004444) were carried out to produce this A22Calpha^- compound mutant. This strain was maintained on an NOD/Caj genetic background by the donating laboratory.

Allele

Symbol: Tcra^tm1Mjo
Name: targeted mutation 1, Michael J Owen
MGI accession ID: MGI:2180883
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: Calpha-; Tcra^tm1Phi; TCRalpha; Tcralpha-; TCRalpha KO; TCRalphae^-
Marker symbol: Tcra
Marker name: T cell receptor alpha chain
Marker synonyms: Tcr alpha; Tcralpha
Chromosome: 14
Strain of origin: 129P2/OlaHsd
Molecular note: The Tcra-C element C1 was disrupted by the insertion of a neomycin selection cassette.

Allele

Symbol: Tg(TcraG9C8)22Fsw
Name: transgene insertion 22, F Susan Wong
MGI accession ID: MGI:5818040
Generation method: Transgenic
Attributes: Inserted expressed sequence
Synonyms: A22
Marker symbol: Tg(TcraG9C8)22Fsw
Marker name: transgene insertion 22, F Susan Wong
Chromosome: UN
Strain of origin: NOD/Caj
Molecular note: Transgenic mice were generated by isolating mouse TCR genomic DNA from G9C8 cloned T-cells, which have previously been shown to have specific reactivity to amino acids 1523 of the insulin beta-chain. Tcralpha (Valpha18S1 Jalpha18 Calpha) chain genomic clone was injected into ova to establish three transgenic mouse lines, 17, 22 and 14. Line 22 was used for subsequent studies.