B6(Cg)-Clec9a^tm1.1Crs/J

Stock number: 017696
Product name: Clec9a^gfp
Strain synonyms: DNGR-1–deficient
Research areas: Cell Biology Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

A membrane-bound form of enhanced green fluorescent protein (EGFP) replaces the coding region of Clec9a and abolishes gene expression.

Detailed description

The coding region of the C-type lectin domain family 9, member a (Clec9a) gene is replaced by a membrane-bound farnesylated form of enhanced green fluorescent protein (EGFP), abolishing gene expression. Clec9a encodes for DNGR-1, an endocytic receptor of the C-type lectin superfamily that is selectively expressed at high levels by CD8α+ dendritic cells (DC) and at lower levels by plasmacytoid DC. DNGR-1 recognizes an intracellular ligand that is exposed in dead cells and facilitates cross-presentation of dead-cell-associated antigens through a mechanism that involves interaction of its intracellular tail with the tyrosine kinase, SYK. Homozygous mice are viable and fertile. In these mice, EGFP expression is detected on CD8α+ DC but not on plasmacytoid DC. DNGR-1 KO mice exhibit a selective deficiency in cross-priming of CD8+ T cells against dead-cell-associated antigens. The phagocytosis of dead cells by DCs is unaffected by loss of DNGR-1 and DC number and phenotype are also unchanged compared to control. These mice may be useful for studying adaptive immune responses to antigens in apoptotic and necrotic cells.

Development

A targeting vector was designed to replace the C-type lectin domain family 9, member a (Clec9a) coding region with a farnesylated form of enhanced green fluorescent protein (EGFP), a polyadenylation signal, and a loxP-flanked neomycin (neo) resistance cassette. This construct was electroporated into (129S6/SvEvTac x C57BL/6) F1-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient C57BL/6 blastocysts and chimeric males were bred with C57BL/6J females. Mutant mice were bred with Tg(Pgk-cre)1Lni mice (on a C57BL/6J congenic background) to remove the neo selection cassette. These Clec9a^gfp/gfp mice were subsequently bred to C57BL/6J mice for at least 7 generations. Upon arrival at The Jackson Laboratory Repository, mice were bred with C57BL/6J inbred mice (Stock No. 000664) for at least one generation.

Allele

Symbol: Clec9a^tm1.1Crs
Name: targeted mutation 1.1, Caetano Reis e Sousa
MGI accession ID: MGI:5298406
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Clec9a
Marker name: C-type lectin domain family 9, member a
Chromosome: 6
Strain of origin: (129S6/SvEvTac x C57BL/6J)F1
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: EGFP expression is detected on CD8α⁺ dendritic cells but not on plasmacytoid DC.
Molecular note: A targeting vector was designed to replace the C-type lectin domain family 9, member a (Clec9a) coding region with a farnesylated form of enhanced green fluorescent protein (EGFP), a polyadenylation signal, and a loxP-flanked neomycin (neo) resistance cassette. Cre-mediated recombination removed the neo cassette.
General note: The expression of NK1.1 (Klrb1c) is linked to Clec9a deficiency in homozygous mice, indicating that the homologous recombination step targeted the chromosome of C57BL/6J origin.