The vast majority of Foxp3^(+)regulatory T cells(Tregs)are generated in the thymus,and several factors,such as cytokines and unique thymic antigen-presenting cells,are known to contribute to the development of these t...The vast majority of Foxp3^(+)regulatory T cells(Tregs)are generated in the thymus,and several factors,such as cytokines and unique thymic antigen-presenting cells,are known to contribute to the development of these thymus-derived Tregs(tTregs).Here,we report the existence of a specific subset of Foxp3^(+)Tregs within the thymus that is characterized by the expression of IL-1R2,which is a decoy receptor for the inflammatory cytokine IL-1.Detailed flow cytometric analysis of the thymocytes from Foxp3^(hCD2)xRAG1^(GFP) reporter mice revealed that the IL-1R2^(+)Tregs are mainly RAG1^(GFP-)and CCR6^(+)CCR7^(-),demonstrating that these Tregs are recirculating cells entering the thymus from the periphery and that they have an activated phenotype.In the spleen,the majority of IL-1R2^(+)Tregs express neuropilin-1(Nrp-1)and Helios,suggesting a thymic origin for these Tregs.Interestingly,among all tissues studied,the highest frequency of IL-1R2^(+)Tregs was observed in the thymus,indicating preferential recruitment of this Treg subset by the thymus.Using fetal thymic organ cultures(FTOCs),we demonstrated that increased concentrations of exogenous IL-1β blocked intrathymic Treg development resulting in a decreased frequency of CD25^(+)Foxp3^(+)tTregs and an accumulation of CD25^(+)Foxp3^(-)Treg precursors.Interestingly,the addition of IL-1R2^(+)Tregs,but not IL-1R2^(+)Tregs,to reaggregated thymic organ cultures(RTOCs)abrogated the IL-1β-mediated blockade,demonstrating that these recirculating IL-1R2^(+)Tregs can quench IL-1 signaling in the thymus and thereby maintain thymic Treg development even under inflammatory conditions.展开更多
基金supported by the CRC 738(to J.H.),CRC/TR 128(to A.W.)and CRC/TRR 221(to M.F.)of the German Research Foundationby grants from the European Research Council(ERC-CoG,#648145 REGiREG)to M.F.Y.E.supported by Ph.D scholarship program no.57129429 of the German Academic Exchange Service(DAAD).
文摘The vast majority of Foxp3^(+)regulatory T cells(Tregs)are generated in the thymus,and several factors,such as cytokines and unique thymic antigen-presenting cells,are known to contribute to the development of these thymus-derived Tregs(tTregs).Here,we report the existence of a specific subset of Foxp3^(+)Tregs within the thymus that is characterized by the expression of IL-1R2,which is a decoy receptor for the inflammatory cytokine IL-1.Detailed flow cytometric analysis of the thymocytes from Foxp3^(hCD2)xRAG1^(GFP) reporter mice revealed that the IL-1R2^(+)Tregs are mainly RAG1^(GFP-)and CCR6^(+)CCR7^(-),demonstrating that these Tregs are recirculating cells entering the thymus from the periphery and that they have an activated phenotype.In the spleen,the majority of IL-1R2^(+)Tregs express neuropilin-1(Nrp-1)and Helios,suggesting a thymic origin for these Tregs.Interestingly,among all tissues studied,the highest frequency of IL-1R2^(+)Tregs was observed in the thymus,indicating preferential recruitment of this Treg subset by the thymus.Using fetal thymic organ cultures(FTOCs),we demonstrated that increased concentrations of exogenous IL-1β blocked intrathymic Treg development resulting in a decreased frequency of CD25^(+)Foxp3^(+)tTregs and an accumulation of CD25^(+)Foxp3^(-)Treg precursors.Interestingly,the addition of IL-1R2^(+)Tregs,but not IL-1R2^(+)Tregs,to reaggregated thymic organ cultures(RTOCs)abrogated the IL-1β-mediated blockade,demonstrating that these recirculating IL-1R2^(+)Tregs can quench IL-1 signaling in the thymus and thereby maintain thymic Treg development even under inflammatory conditions.
