B6.Cg-H2-Ab1^b-tm1Gru Tg(KRT14-H2-Ab1)1Glm/TmlJ

Stock number: 038339
Product name: K14-Abetab; AbetabKO
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

K14/I-A^bbb transgenic mice express a cDNA encoding endogenous mouse H2-Ab1 (histocompatibility 2, class II antigen A, beta 1) under the control of the human keratin 14 (KRT14) promoter on a H2-Ab1 deficient background (H2-Ab1^tm1Gru). Double mutant mice retain positive selection of CD4+ T cells, but have impaired clonal deletion. This strain may be useful for studies of thymic development and for understanding functions of CD4+ T cell homeostasis that are MHC class II-independent.

Detailed description

H2-Ab1 (histocompatibility 2, class II antigen A, beta 1) encodes the beta subunit of the major histocompatibility complex class II IA. It is orthologous to human HLA-DQB2 (major histocompatibility complex, class II, DQ beta 2). MHC class II molecules are involved in the initiation of the immune response by presenting peptide antigen from exogenous proteins to T cells.

K14/I-A^bbb transgenic mice express a cDNA encoding endogenous mouse H2-Ab1 under the control of the human keratin 14 (KRT14) promoter on a H2-Ab1 deficient background (H2-Ab1^tm1Gru). Expression of the transgene is restricted to thymic cortical epithelium. Mice homozygous for the knockout and hemizygous for the transgene exhibit increased numbers of CD4+ T cells in the peripheral lymphocyte population (5-18%) as compared to H2-Ab1-deficient mice, thus rescuing positive selection of CD4+ T cells. However, negative selection of CD4+ T cells is compromised; approximate 5% of peripheral CD4 T cells are autoreactive due to limited class II I-A^b expression in the thymic cortex. This strain may be useful for studies of thymic development and for understanding functions of CD4+ T cell homeostasis that are MHC class II-independent. Mice homozygous for the KO and hemizygous for the transgene are viable and fertile. The transgene is viable as a homozygote, however, litters are small and pups are decreased in weight.

Development

Mice carrying Tg(KRT14-H2-Ab1)1Glm and H2-Ab1^tm1Gru were combined to generate this strain.

The H2-Ab1^tm1Gru targeting vector was designed by Michael Grusby (Harvard Medical School) to insert a neomycin selection cassette in exon 2 of the H2-Ab1 (histocompatibility 2, class II antigen A, beta 1) locus on chromosome 17. The construct was electroporated into 129S2/SvPas-derived D3 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. Chimeric males were crossed to C57BL/6J females. Mice from the colony were transferred to Dr. Terri Laufer (Harvard Medical School) and backcrossed to C57BL/6J for 25 generations.

The K14/I-A^bbb transgenic construct contains the human KRT14 promoter directing expression of a cDNA encoding the endogenous mouse H2-Ab1 gene (I-A^b), followed by the human growth hormone gene and polyA signal. The transgene was injected into the pronuclei of fertilized C57BL/6 oocytes. Founder line 1 was bred to B6.129S2-H2-Ab1^tm1Gru mice for more than 5 generations. The donating investigator indicates that insertion site and copy number are unknown.

Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: H2-Ab1^b-tm1Gru
Name: targeted mutation 1, Michael J Grusby
MGI accession ID: MGI:2158420
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: [KO]Ab^b; A^bbeta^-; Ab1^tm1Gru; Abb-; Abb^tm1; Abeta-; Abeta^b-; C2-; H2-Ab1^-; H2-Ab1^tm1Glm; H2-Ab1^tm1Gru; I-A^b-; IAb^-; IAbeta-; I-Abeta^b-; MHC class II-; MHC-II-deficient; mII^-
Marker symbol: H2-Ab1
Marker name: histocompatibility 2, class II antigen A, beta 1
Marker synonyms: A beta; Abeta; Bb; CELIAC1; DQB2; H-2Ab; H2-Ab; HLA-DQB; HLA-DQB1; HLA-DXB; I-A^b; Ia2; Ia-2; IAb; I-Abeta; IDDM1; Rmcs1; RT1.B
Chromosome: 17
Strain of origin: 129S2/SvPas
Molecular note: A neomycin selection cassette was inserted into exon 2. In addition, the ES cell line used was derived from the 129S2/SvPas strain, which carries a deletion in the promoter region of H2-Ea. Consequently, these MHC class II molecule-deficient mice lacked cell surface expression of both class II-A and class II-E MHC proteins.

Allele

Symbol: Tg(KRT14-H2-Ab1)1Glm
Name: transgene insertion 1, Laurie Glimcher
MGI accession ID: MGI:6433999
Generation method: Transgenic
Attributes: Inserted expressed sequence
Marker symbol: Tg(KRT14-H2-Ab1)1Glm
Marker name: transgene insertion 1, Laurie Glimcher
Chromosome: UN
Strain of origin: C57BL/6
Molecular note: H2-Ab1 mouse cDNA is expressed in keratinocytes and stratified squamous epithelia under the control of the human keratin 14 promoter.