STOCK F8^tm1Kaz Tg(Alb-F8*R593C)T4Mcal/J

Stock number: 017706
Research areas: Hematological Research

Description

These mice contain a huFVIII-R593C transgene, designed with the murine albumin (Alb) promoter driving expression of an altered human coagulation factor VIII (F8) cDNA harboring a mutation that is frequently observed in patients with mild hemophilia A. These mice also carry a knock-out of the F8 gene and are deficient for endogenous F8 protein.

Detailed description

The huFVIII-R593C transgene was designed with the murine albumin (Alb) promoter driving expression of a mutated human coagulation factor VIII (F8) cDNA. Mice carrying this transgene were bred to mice deficient in endogenous F8. F8 is a coagulation factor, and mutations of this gene have been linked to hemophilia A. As such, the donating investigator reports that these mice will die due to blood loss from a tail clip (see additional note below). These double mutant mice are tolerant of human F8 (hF8) injection, and have no F8 activity. They produce very little inhibitory antibodies and lack F8 responsive T cells or B cells after treatment with human F8. When treated with a hF8 expression plasmid driven by a liver specific human α1 anti trypsin promoter and an attB phiC31 integrase site, in conjunction with phiC31 integrase treatment, this hF8 integrates into the host genome at specific "pseudo-attP sites" and results in long-term gene therapy. This strain may be useful for studying hF8 gene therapy treatments for Hemophilia A patients.

Additional note on tail clipping: The donating investigator reports that these mice will die due to blood loss from a tail clip. The donating investigator suggests no tail clipping be performed on mice younger than 4 weeks of age, and tail clipping with cauterization may be used for mice older than 4 weeks of age.

Development

The huFVIII-R593C transgene was designed with the murine albumin (Alb) promoter driving expression of human coagulation factor VIII (F8) cDNA. This transgene contains a cytosine to thymine mutation, resulting in an Arginine to Cysteine missense mutation at amino acid 612, which is prevalent in patients with Hemophilia A. The original site of this mutation was amino acid 593. Recent sequencing at The Jackson Laboratory (2022) has verified this mutation to be located at amino acid 612. The transgene was microinjected into fertilized FVB/N oocytes, and mice from founder line T4 were then bred to C57BL/6J mice to establish a colony. These mice were backcrossed to C57BL/6J mice for at least 5 generations. Subsequently, these huFVIII-R593C mice were bred to B6;129S4-F8^tm1Kaz/J mice (see Stock No. 004424), which are deficient in endogenous F8. Upon arrival at The Jackson Laboratory Repository, mice were bred to B6;129S4-F8^tm1Kaz/J mice (Stock No. 004424) for one generation.

Allele

Symbol: F8^tm1Kaz
Name: targeted mutation 1, Haig H Kazazian Jr
MGI accession ID: MGI:2179981
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: F8
Marker name: coagulation factor VIII
Chromosome: X
Strain of origin: 129S4/SvJae
Molecular note: A neomycin resistance cassette replaced 293 bp of sequence, including 7 bp at the 3' end of exon 16 and 286 bp at the 5' end of intron 16. Two different activity assays indicated that the mutated allele produced protein with levels of activity less than 1% of wild-type levels.

Allele

Symbol: Tg(Alb-F8*R593C)T4Mcal
Name: transgene insertion T4, Michele Calos
MGI accession ID: MGI:5300683
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(Alb-F8*R593C)T4Mcal
Marker name: transgene insertion T4, Michele Calos
Chromosome: UN
Strain of origin: FVB/N
Expressed genes: F8,coagulation factor VIII,human
Molecular note: The transgene was designed with the murine albumin (Alb) promoter driving expression of human coagulation factor VIII (F8) cDNA. This transgene contains an Arginine to Cysteine missense mutation at amino acid 612 (originally stated as 593), which is prevalent in patients with Hemophilia A.