B6.129P2-S1pr1^tm1.1Cys/J

Stock number: 021017
Research areas: Immunology, Inflammation and Autoimmunity Research

Description

These mice carry a mutation in the S1pr1 (sphingosine-1-phosphate receptor 1) gene that influences the migration of lymphocytes between the blood and tissues.

Detailed description

S1pr1 (sphingosine-1-phosphate receptor 1) is a G_i-coupled receptor expressed on the surface of lymphocytes. When it recognizes high levels of ligand (S1P) in the blood and lymph, egress of the cells from lymphoid organs into the blood is promoted. Downregulation or desensitization of this receptor enables lymphocytes to subsequently migrate from the blood into tissues.

The last 12 amino acids of the encoded protein carry a motif that is important for receptor desensitization following exposure to ligand. These mice carry a Thr-Ser-Ser (TSS) to Ala-Ala-Ala (AAA) mutation in this region that leads to a loss in sensitivity for ligand-mediated receptor down-modulation, leading to partial block in the desensitization process.

Mice are resistant to S1P-mediated S1PR1 internalization in naive T cells, follicular B cells and marginal zone (MZ) B cells. Augmented responses to S1P in chemotaxis assays and higher S1PR1 expression on MZ B cells are also seen. In addition, MZ B cells in mutant mice show abnormal distribution; they are confined to the marginal zone compartment and absent from the follicles. Mutant mice have normal numbers of naive T cells, follicular B cells and MZ B cells. Heterozygous and homozygous mutant mice show essentially the same phenotype.

Development

A Thr-Ser-Ser (TSS) motif located in the C-terminus of the gene was substituted by Ala-Ala-Ala (AAA) through targeted mutation of 129P2/OlaHsd-derived E14 embryonic stem (ES) cells. A loxP-flanked neomycin resistance cassette was also inserted after the stop codon. The neomycin cassette was excised through crosses with B6.C-Tg(CMV-cre)1Cgn/J mice (see Stock No. 006054). Resultant animals were backcrossed to C57BL/6 for 7 generations by the donating lab.

Allele

Symbol: S1pr1^tm1.1Cys
Name: targeted mutation 1.1, Jason G Cyster
MGI accession ID: MGI:5295051
Generation method: Targeted
Marker symbol: S1pr1
Marker name: sphingosine-1-phosphate receptor 1
Chromosome: 3
Strain of origin: 129P2/OlaHsd
Molecular note: Nucleotide substitutions replaced the threonine and serines in the TxxSS motif in the last 12 amino acids of the sequence with alanines (p.T371A and p.(S374_S375delinsAA)). A floxP site flanked neomycin resistance gene cassette was inserted into the 3' UTR. Subsequent cre-mediated recombination removed the neo cassette.