C57BL/6-Stat2^{tm1.1(STAT2)Diam}/AgsaJ

Stock number: 031630
Product name: hSTAT2 KI , C57BL/6 hSTAT2 KI , human STAT2 knock-in
Research areas: Cancer Research, Cell Biology Research, Immunology, Inflammation and Autoimmunity Research, Research Tools, Virology Research

Description

C57BL/6 hSTAT2 KI mice have the human STAT2 knock-in allele on the C57BL/6 genetic background. Humanized STAT2 knock-in mice are useful for studying immune system cytokine signaling. More specifically, because they overcome the inherent inability of Zika virus (ZIKV) to bind and degrade mouse STAT2, C57BL/6 hSTAT2 KI homozygotes are an immunocompetent C57BL/6 mouse model for studying ZIKV pathogenesis.

Detailed description

STAT2 is a member of the signal transducer and activator of transcription (STAT) protein family members. In response to cytokines and growth factors (e.g., interferon [IFN]), STAT proteins are phosphorylated and then form complexes that translocate to the cell nucleus where they act as transcription activators. Although the Zika virus (ZIKV) NS5 protein evades the human IFN signaling response by binding to and degrading STAT2, it is unable to bind efficiently to mouse STAT2 and thus lacks the ability to antagonize the mouse IFN response.

C57BL/6 hSTAT2 KI mice have the human STAT2 knock-in allele on the C57BL/6 genetic background. The human STAT2 knock-in allele has the endogenous mouse Stat2 coding sequence (spanning from part of exon 2 through part of exon 24) replaced with the corresponding human STAT2 coding sequences. Western blot of splenocytes stimulated with poly(I:C) confirmed the loss of mouse STAT2 and the expression of human STAT2.
Both heterozygous and homozygous mice are viable and fertile with no developmental, behavioral or reproductive abnormalities.
Because C57BL/6 hSTAT2 KI homozygotes express human STAT2 in place of mouse STAT2, they are an immunocompetent C57BL/6 mouse model useful for studying ZIKV pathogenesis - allowing researchers to overcome the inherent inability of ZIKV strains to bind and degrade mouse STAT2.

Development

The human STAT2 knock-in allele (hSTAT2 KI) was created for/designed by Dr. Adolfo Garcia-Sastre (Icahn School of Medicine at Mount Sinai) to replace the endogenous mouse signal transducer and activator of transcription 2 (Stat2) coding sequence (spanning from part of exon 2 through part of exon 24) with the corresponding human STAT2 coding sequence. The hSTAT2 KI allele retains the endogenous mouse Stat2 5' untranslated region, promoter sequences (exon 1 and part of exon 2) and 3' untranslated region. The targeting vector was created using mouse Stat2 sequences from C57BL/6J BAC RPCIB-731 and human STAT2 sequences from human BAC RPCIB-753. The targeting vector also inserted a frt-flanked neomycin resistance cassette in intron 1 and a F3-flanked puromycin resistance cassette in intron 24.

The construct was electroporated into TaconicArtemis C57BL/6NTac-derived "Art B6 3.6" embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. Chimeric animals were bred with CAG-FLPe transgenic mice (on a C57BL/6 genetic background) for germline transmission and simultaneous deletion of the neomycin and puromycin cassettes.

The resulting hSTAT2 KI mice were bred with C57BL/6J and the CAG-FLPe transgene was removed. The C57BL/6 hSTAT2 KI colony was thereafter maintained on the C57BL/6 genetic background (mix of C57BL/6J and C57BL/6N) prior to sending males with black coat color to The Jackson Laboratory Repository in 2018. 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: Stat2^{tm1.1(STAT2)Diam}
Name: targeted mutation 1.1, Michael S Diamond
MGI accession ID: MGI:6156567
Generation method: Targeted
Attributes: Inserted expressed sequence; Humanized sequence
Synonyms: hSTAT2 KI
Marker symbol: Stat2
Marker name: signal transducer and activator of transcription 2
Chromosome: 10
Strain of origin: C57BL/6NTac
Molecular note: The targeting vector was created using mouse Stat2 sequences from C57BL/6J BAC RPCIB-731 and human STAT2 sequences from human BAC RPCIB-753. The targeting vector also inserted an FRT-flanked neomycin resistance cassette in intron 1 and a F3-flanked puromycin resistance cassette in intron 24. The vector is designed replace the endogenous mouse Stat2 coding sequence (spanning from part of exon 2 through part of exon 24) with the corresponding human STAT2 coding sequence. The allele retains the endogenous mouse Stat2 5' untranslated region, promoter sequences (exon 1 and part of exon 2) and 3' untranslated region. Flp-mediated recombination removed the FRT-flanked neo and puro cassettes.