B6.Cg-Stat1^tm1Dlv Tg(K18-ACE2)2Prlmn/J

Stock number: 035077
Product name: K18-hACE2 ; Stat1^-
Research areas: Cell Biology Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Mouse/Human Gene Homologs, Research Tools, Virology Research

Description

These mice express human ACE2, the receptor used by the severe acute respiratory syndrome coronavirus (SARS-CoV) to gain entry to cells. The human keratin 18 (KRT18) promoter directs expression to epithelia, including airway epithelial cells where infections typically begin. Recent research indicates the K18-hACE2 transgene may be useful in studying antiviral therapies for the 2019 novel coronavirus (SARS-CoV-2) pathogenesis and the disease outbreak COVID-19.

This strain also contains the Stat1^- targeted mutation which may result in reduced immune response and increased susceptibility to SARS-CoV viral infection during clinical trials.

Detailed description

Please see the K18-hACE2 datasheet (Stock No. 034860) for important safety/handling and any updated information on K18-hACE2 mice in SARS-CoV-2 research.
Please note, these mice should be handled in a manner consistent with CDC/ABSA/WHO guidelines for prevention of human infection with the SARS-CoV-2 virus. Proper PPE and handling methods should be used at all times when working with these mice. Additional important guidelines for using SARS-CoV-2 susceptible mouse lines.

Stock No. 035077 K18-hACE2 ; Stat1^- is a multiple mutant strain assembled by breeding Stock Nos. 034860 and 012606. In an attempt to offer popular alleles together, mouse lines may be bred together for purpose of researchers to study and characterize. It should be noted that the phenotype of Stock No. 035077 could vary from that originally described for the individual mouse lines used to assemble it. We may modify the strain description if necessary as published results become available. Each mutant allele is briefly described below [October 2020].

K18-hACE2 transgenic mice express the receptor for severe acute respiratory syndrome (SARS), caused by a coronavirus (SARS-CoV) in airway and other epithelia under control of the human keratin 18 (KRT18) promoter. Specifically, these mice contain 2.5 kb of the KRT18 genomic sequence, including the promoter, and the first intron (with a mutation in the 3' splice acceptor site to reduce exon skipping) and a translational enhancer (TE) sequence from alfalfa mosaic virus, upstream of the human angiotensin I converting enzyme (peptidyl-dipeptidase A) 2 coding sequence (hACE2), followed by exons 6-7 and the poly(A) signal of the human K18 gene. These elements have been found to be necessary for high-level expression and epithelial cell specificity of hACE2, the primary host cell receptor for SARS-CoV. In these mice, from founder line 2, K18-hACE2 transgene expression is evident in airway epithelial cells (but not in alveolar epithelia), as well as in epithelia of other internal organs, including the liver, kidney, and gastrointestinal tract. Recent research indicates that this line may also be useful in studies related to the study of 2019 novel coronavirus (SARS-CoV-2) pathogenesis.

Addition of the Stat1^- targeted mutation may result in reduced immune response and increased susceptibility to SARS-CoV viral infection during clinical trials.

The K18-ACE2 transgenic mouse line (Stock No. 034860) is viable and fertile. The Stat1^- mouse line (Stock No. 012606) homozygotes are able to be maintained in high health status (specific pathogen-free) vivaria, but when maintained in low health barrier rooms homozygous null Stat1^- animals tend to be runted and die within 48 hours of weaning (hepatic necrosis due to viral infection).
Stock No. 035077 is viable and fertile as hemizygous K18-ACE2 and heterozygous Stat1^-. However, it is not yet known if Stock No. 035077 may be maintained as homozygous for both alleles [October 2020].

Development

The ~6.8 kb K18-hACE2 transgene was designed with, from 5' to 3', 2.5 kb of genomic sequence, including the promoter, and the first intron (with a mutation in the 3' splice acceptor site to reduce exon skipping) from the human keratin 18 (KRT18) gene, and a translational enhancer (TE) sequence from alfalfa mosaic virus. This was followed by the human angiotensin I converting enzyme (peptidyl-dipeptidase A) 2 (hACE2) coding sequence, and exons 6-7 and the poly(A) signal of the human K18 gene. This transgene was microinjected into fertilized (C57BL/6J x SJL/J)F2 oocytes. K18-hACE2 mice from founder line 2, with 8 copies of the transgene, were subsequently maintained by breeding transgenic mice with C57BL/6 mice for at least two generations (the genetic background of the mice sent to The Jackson Laboratory was later determined to be C57BL/6N via SNP testing). Upon arrival, three backcrosses to C57BL/6J (Stock No. 000664) were then performed to rederive, establish and expand a congenic colony at The Jackson Laboratory as Stock No. 034860. Some of these mice were bred to Stat1^- mice (Stock No. 012606), carrying a knock-out mutation for the mouse Stat1 (signal transducer and activator of transcription 1) gene, to create this new strain as Stock No. 035077.

In May 2020, analysis commissioned by The Jackson Laboratory determined that multiple copies of the Tg(K18-ACE2)2Prlmn transgene integrated at a single site on chromosome 2 (99,209,508-99,220,724; mouse mm10). An ~11 kb duplication of the host genome (chr2:99,209,508-99,220,724) is present at both ends of the integrated transgene array. Currently, there are no genes annotated in this region. The transgene copy number of the hemizygous mouse is estimated to be 8 full copies (or 12-30 partial copies).

Allele

Symbol: Stat1^tm1Dlv
Name: targeted mutation 1, David E Levy
MGI accession ID: MGI:1930947
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: STAT^-; Stat1-; Stat1 KO
Marker symbol: Stat1
Marker name: signal transducer and activator of transcription 1
Marker synonyms: 2010005J02Rik; CANDF7; DD6G4-4; IMD31A; IMD31B; IMD31C; ISGF-3; STAT91
Chromosome: 1
Strain of origin: 129S/SvEv-Gpi1^c
Molecular note: A neomycin resistance cassette replaced 5.7 kb of sequence, including 3 exons and a portion of a fourth encoding amino acids 221-365. This allele produces a partial nonfunctional protein product.

Allele

Symbol: Tg(K18-ACE2)2Prlmn
Name: transgene insertion 2, Stanley Perlman
MGI accession ID: MGI:6389235
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Synonyms: K18-hACE2
Marker symbol: Tg(K18-ACE2)2Prlmn
Marker name: transgene insertion 2, Stanley Perlman
Chromosome: 2
Strain of origin: (C57BL/6J x SJL/J)F2
Site of expression: Epithelia, including airway epithelia.
Molecular note: The ~6.8 kb transgene was designed with, from 5' to 3', 2.5 kb of genomic sequence, including the promoter, and the first intron (with a mutation in the 3' splice acceptor site to reduce exon skipping) from the human K18 gene, and a translational enhancer (TE) sequence from alfalfa mosaic virus. This was followed by the human angiotensin I converting enzyme (peptidyl-dipeptidase A) 2 (hACE2) coding sequence (lacking the last exon), and exons 6-7 and the poly(A) signal of the human K18 gene. The transgene integrated at a single site on chromosome 2 (99,209,508-99,220,724; mouse mm10). An ~11 kb duplication of the host genome (chr2:99,209,508-99,220,724) is present at both ends of the integrated transgene array. Currently, there are no genes annotated in this region. The transgene copy number of the hemizygous mouse is estimated to be 8 full copies (or 12-30 partial copies). Transgene expression is evident in airway epithelial cells (but not in alveolar epithelia), as well as in epithelia of other internal organs, including the liver, kidney, and gastrointestinal tract.