B6.129S4(D2)-Casp4^tm1Yuan/J

Stock number: 024698
Product name: casp-11-/-
Research areas: Apoptosis Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

Homozygous knock-out mice are severely defective in LPS-induced IL-1β secretion and are resistant to LPS-induced septic shock. They may be suitable in applications involving the study of inflammatory and apoptosis responses.

Detailed description

Caspase 4 (also known as caspase 11) is a critical upstream regulator in the caspase cascade with an important dual role in regulating both inflammatory response and apoptosis. Splenocytes harvested from homozygous mice both before and after treatment with LPS show an absence of casp-11 protein isoforms. While casp-11-defeciency has no effect upon the expression of Interleukin-1b(IL-1β)-converting enzyme (ICE or caspase-1) precursor/immature proteins (pro-ICE), ICE activation (via proteolytic cleavage of pro-ICE) is defective. As such, homozygotes are severely defective in IL-1β maturation and secretion after LPS stimulation, and are resistant to LPS-induced septic shock. Homozygous mice are also resistant to the inflammatory/apoptotic Parkinson's disease-like pathology that results following acute MPTP neurotoxin administration. Homozygotes are viable and fertile.

These mice may be useful in studying cell migration, cytokine maturation/secretion, and apoptosis during inflammatory responses, as well as actin dynamics (actin depolymerization) or neurotoxicity. During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background.

Development

A targeting vector was designed to replace a 1.5 kb genomic fragment (including a 16 amino acid region of exon 5 harboring the active site pentapeptide QACRG) of the endogenous gene with a PGKneo cassette. The construct was electroporated into 129S4/SvJae-derived J1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric males were bred to (C57BL/6J x DBA2)F1 females. Mice harboring this caspase-4 (also called caspase-11 or casp-11) mutation were backcrossed to C57BL/6 inbred mice for at least 8 generations prior to arrival at The Jackson Laboratory. During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background. Upon arrival, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.

In 2015-2016, SNP (single nucleotide polymorphism) panel analyses, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the live colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, all 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

In 2017, a more thorough SNP panel analysis (43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers distinguishing C57BL/6 substrains), was performed on our live colony. All animals tested were C57BL/6 allele-type with a single exception; one mouse was heterozygous (C57BL/6;129) at one of the chromosome 15 markers [~33 Mbp]. Furthermore, 4 of the 5 C57BL/6 substrain markers were found to be segregating for C57BL/6N or C57BL/6J. These data continue to support that Stock No. 024698 is a C57BL/6-congenic strain with contributions from C57BL/6N and C57BL/6J genetic backgrounds.

Allele

Symbol: Casp4^tm1Yuan
Name: targeted mutation 1, Junying Yuan
MGI accession ID: MGI:2159366
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Casp4
Marker name: caspase 4, apoptosis-related cysteine peptidase
Chromosome: 9
Strain of origin: 129S4/SvJae
Molecular note: A neomycin resistance cassette replaced a 1.5 kb genomic fragment containing sequences encoding 16 amino acids of the active site. Western blot analysis on lysates derived from spleen of both LPS-injected and control homozygous mice confirmed that no detectable protein is expressed from this allele.