title: Inflammation in vivo is modulated by GPR83 isoform-4 but not GPR83 isoform-1 expression in regulatory T cells.
abstract: Most recently, we have described the G-protein coupled receptor 83 (GPR83), which is highly expressed by CD4(+)CD25(+) regulatory T cells (Tregs) to be involved in the induction of CD4(+)Foxp3(+) Tregs in the course of an ongoing immune response. Four GPR83 isoforms have been described. Here, we have shown that GPR83 isoform-4, which differs from GPR83 isoform-1 by 20 additional aminoacids in the second cytoplasmatic loop, is predominantly expressed by Tregs. Interestingly, GPR83 isoform-4 but not GPR83 isoform-1 retrovirally transduced T cells were able to interfere with inflammatory responses in vivo. Re-analysis of GPR83 transduced T cells revealed that this in vivo acquisition of suppressive activity was associated with the induction of Treg-associated molecules including Foxp3 in GPR83 isoform-4 but not GPR83 isoform-1 transduced CD4(+) T cells under inflammatory conditions. Our results suggest that the 20 additional aminoacids within GPR83 isoform-4 are involved in Treg induction during inflammatory immune responses.
authors.affiliation: Institute of Medical Mircobiology, University Hospital Essen, Essen, Germany. wiebke.hansen@uk-essen.de
authors.forename: W
authors.initials: W
authors.lastname: Hansen
authors.forename: A M
authors.initials: AM
authors.lastname: Westendorf
authors.forename: T
authors.initials: T
authors.lastname: Toepfer
authors.forename: S
authors.initials: S
authors.lastname: Mauel
authors.forename: R
authors.initials: R
authors.lastname: Geffers
authors.forename: A D
authors.initials: AD
authors.lastname: Gruber
authors.forename: J
authors.initials: J
authors.lastname: Buer
mesh_terms: D006801:Humans; D010641:Phenotype; D020033:Protein Isoforms / Q000235:genetics / Q000502:physiology*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000502:physiology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: C501983:GPR83 protein, human; D020033:Protein Isoforms; D043562:Receptors, G-Protein-Coupled