NOD/ShiLt-Aicda^em1Cml/DvsJ

Stock number: 032322
Product name: NOD.Aicda^-
Research areas: Cell Biology Research, Diabetes and Obesity Research, Immunology, Inflammation and Autoimmunity Research

Description

These CRISPR/Cas9-generated NOD.Aicda^- mice carry a knock-out allele of the mouse Aicda (activation-induced cytidine deaminase) gene that disrupts processes of class switch recombination (CSR) and somatic hypermutation (SHM) in B lymphocytes. Aicda ablation significantly inhibits type 1 diabetes (T1D) development.

Detailed description

The Aicda (activation-induced cytidine deaminase) gene encodes a protein that induces genome-wide DNA breaks and is required for class switch recombination (CSR) and somatic hypermutation (SHM) induction.

These NOD.Aicda^- mutant mice carry a CRISPR/Cas9-derived mutation in the 5'UTR of the mouse Aicda gene. The mutation incorporates a 2 bp deletion and a 309 bp insertion that ablates protein production.

Homozygous mice display significantly decreased CSR, as determined by in vitro anti-CD40 and IL-4 stimulation of purified B lymphocytes. Homozygous females develop T1D at a significantly reduced rate (~90% survival at 30 weeks of age), as compared to female wildtype NOD controls (~25% survival at 30 weeks). Heterozygotes develop T1D at an intermediate rate. Homozygotes remaining free of overt T1D at 18 weeks of age are still characterized by significant levels of insulitis that is not delayed in onset.

Evidence suggests that diminished T1D development in NOD.Aicda^-/- mice is due, at least in part, to an expansion of CD73⁺ B lymphocytes with the capacity to suppress pathogenic T cell responses. Genetic or pharmacologic blockade of B lymphocyte Aicda-dependent affinity-maturation processes in NOD mice drives diversion to a CD73⁺ regulatory phenotype capable of inhibiting autoimmune T1D development.

Development

CRISPR-Cas9 technology was used to generate a knock-out allele. Cas9 mRNA and single-guide RNA (sgRNA; 5'-gaaattaatacgactcactataggAGTCACGCTGGAGACCGATAgttttagagctagaaatagc-3') were injected into the cytoplasm of NOD/ShiLtDvs zygotes. Line 1 was maintained on the NOD/ShiLtDvs genetic background by the donating laboratory.

Allele

Symbol: Aicda^em1Cml
Name: endonuclease-mediated mutation 1, Caroline Leeth
MGI accession ID: MGI:6194206
Generation method: Endonuclease-mediated
Attributes: Null/Knockout
Synonyms: Line 1
Marker symbol: Aicda
Marker name: activation-induced cytidine deaminase
Marker synonyms: aid; ARP2; CDA2; HEL-S-284; HIGM2
Chromosome: 6
Strain of origin: NOD/ShiLtDvs
Molecular note: CRISPR/cas9 endonuclease mediated genome editing is used to introduce a 2bp deletion (position 89-90 of the gene) and a 309bp insertion into exon 1. The mutation is in the 5'-UTR and generates a null allele.