Project description:CD25 (IL-2R) can be expressed on the surface of immune cells in the absence of other chains of the interleukin-2 receptor (IL-2R), which are indispensable for IL-2 signaling. We identified two novel mast cell subsets, characterized by the differential expression of surface CD25, and by the ability to produce different cytokines and to proliferate, both in vitro and in vivo. We provide evidence that functional differences between the two mast cell populations were dependent on CD25 itself, which directly modulated mast cell proliferation and responses in vivo. These effects were completely independent from IL-2 or the expression of the other chains of the high-affinity IL-2R, indicating an autonomous and previously unappreciated role for CD25 in regulating cell functions. Similar results were also obtained in dendritic cells, which are known to express CD25 but to be unresponsive to IL-2. Our findings indicate a general role for CD25 in contexts where IL-2 signaling is not involved, and may have important implications for all mast cell-related diseases, including mastocytosis, where CD25 is aberrantly expressed on pathogenic mast cells. Total mRNA of FACS-sorted CD25pos and CD25neg populations of primary bone marrow-derived mast cells (BMMCs) was extracted and subjected to by multiparallel sequencing.
Project description:CD25 (IL-2R) can be expressed on the surface of immune cells in the absence of other chains of the interleukin-2 receptor (IL-2R), which are indispensable for IL-2 signaling. We identified two novel mast cell subsets, characterized by the differential expression of surface CD25, and by the ability to produce different cytokines and to proliferate, both in vitro and in vivo. We provide evidence that functional differences between the two mast cell populations were dependent on CD25 itself, which directly modulated mast cell proliferation and responses in vivo. These effects were completely independent from IL-2 or the expression of the other chains of the high-affinity IL-2R, indicating an autonomous and previously unappreciated role for CD25 in regulating cell functions. Similar results were also obtained in dendritic cells, which are known to express CD25 but to be unresponsive to IL-2. Our findings indicate a general role for CD25 in contexts where IL-2 signaling is not involved, and may have important implications for all mast cell-related diseases, including mastocytosis, where CD25 is aberrantly expressed on pathogenic mast cells.
Project description:Type 1 regulatory T (Tr1) cells are one of the regulatory T cell subsets that are characterized by the production of high amount of IL-10 and lack of FOXP3 expression. Lymphocyte-activation gene 3 (LAG3) is a CD4 homologue molecule and we have previously reported that LAG3 is expressed on IL-10 producing regulatory T cells. However, naturally occurring Tr1 cells in human secondary lymphoid tissue have not been detected. We identified CD4+CD25-LAG3+ T cells in human tonsil. We compared mRNA expression of five CD4+ T cell subsets in tonsil using microarray analysis (CD4+CD25-LAG3+ T cells, CD4+CD25-CXCR5+PD-1+ follicular helper T cells (TFH), CD4+CD25+ T cells, CD4+CD25-LAG3-CD45RO+ cells and CD4+CD25-LAG3-CD45RO- cells). A human tonsil was obtained from a patient undergoing routine tonsillectomy, and five tonsillar CD4+ T cell subsets were sorted (each 1 x 10^5 cells). There is no biological replication.
Project description:CD25, the high affinity interleukin-2 (IL-2) receptor alpha-chain, is rapidly upregulated by antigen-specific CD8+ T cells after T cell receptor stimulation. We demonstrated that during an acute viral infection, CD25 expression was dynamic, and a subset of virus-specific CD8+ T cells sustained CD25 expression longer than the rest. Examination of the in vivo fate of effector CD8+ T cells exhibiting differential responsiveness to IL-2 revealed that CD25lo cells, which were relatively less sensitive to IL-2, preferentially upregulated CD127 and CD62L and gave rise to the functional long-lived memory pool. In contrast, CD25hi cells that accumulate enhanced IL-2 signals, proliferated more rapidly, were prone to apoptosis, exhibited a more pronounced effector phenotype, and appeared to be terminally differentiated. Sustained IL-2 receptor signaling resulted in increased CD8+ T cell proliferation, higher granzyme B expression and exaggerated contraction after antigen clearance. These data support the hypothesis that prolonged IL-2 signals during priming promote terminal effector differentiation of CD8+ T cells. Experiment Overall Design: An important question in memory development is understanding the differences between effector CD8 T cells that die versus effector cells that survive and give rise to memory cells. In this study we have performed genomic profiling of terminal effectors and memory precursors as defined by CD25 heterogeneity, towards better understanding the generation of these subsets. The two effector subsets were FACS purified based on the amount of cell surface CD25 expression into CD25lo and CD25hi subsets during the early expansion phase (Days 3-4 post-infection) and analyzed for their gene expression profiles (by genome-wide microarray analyses).
Project description:Type 1 regulatory T (Tr1) cells are one of the regulatory T cell subsets that are characterized by the production of high amount of IL-10 and lack of FOXP3 expression. Lymphocyte-activation gene 3 (LAG3) is a CD4 homologue molecule and we have previously reported that LAG3 is expressed on IL-10 producing regulatory T cells. However, naturally occurring Tr1 cells in human secondary lymphoid tissue have not been detected. We identified CD4+CD25-LAG3+ T cells in human tonsil. We compared mRNA expression of five CD4+ T cell subsets in tonsil using microarray analysis (CD4+CD25-LAG3+ T cells, CD4+CD25-CXCR5+PD-1+ follicular helper T cells (TFH), CD4+CD25+ T cells, CD4+CD25-LAG3-CD45RO+ cells and CD4+CD25-LAG3-CD45RO- cells).
Project description:TGF-beta3 produced by developing Th17 cells induces highly pathogenic T cells that are functionally and molecularly distinct from TGF-beta1-induced Th17 cells. The microarray data represent a distinct molecular signature for pathogenic versus non-pathogenic Th17 cells. Total of seven groups with two to four samples per group from two independent experiments. The no cytokines group (Th0) was used as a control to normalize the data. 7 groups: B6: (IL-1beta, IL-6) B623: (IL-1beta, IL-6, IL-23) T16: (TGF-beta1, IL-6) T1623: (TGF-beta1, IL-6, IL-23) T36: (TGF-beta3, IL-6) T3623: (TGF-beta3, IL-6, IL-23) NOCYTO: no cytokines
Project description:Recent studies have demonstrated that mature regulatory T cells ( Tregs) develop in the thymus via two pathways involving distinct Treg progenitors (TregP) - CD25+FOXP3- (CD25+ TregP) and CD25-FOXP3lo (FOXP3lo TregP) Treg progenitors. To examine this process in more detail we carried out single-cell RNA-Seq and TCR-Seq on sorted CD4+CD8+ double-positive (DP) thymocytes, CD4+ Ssingle -positive (CD4SP)P thymocytes, CD25+ TregP, FOXP3lo TregP, mature CD25+FOXP3+ Tregs and recirculating/long-term resident Tregs (RT-Tregs). Sorted populations were individually hashtagged and then combined into one scRNA-Seq/TCR-Seq library before sequencing and subsequent analysis. We found that both CD25+ TregP and FOXP3lo TregP arise via an initial agonist activated state that gives rise to a second transitional stage before differentiating into mature Tregs. Using both scRNA-Seq and bulk RNA-Seq on sorted thymocyte subsets we demonstrate that CD25+Foxp3- TregP are significantly enriched for Il2 production, suggesting that they are the major source of IL-2 needed to convert TregP into mature Tregs. Using TCR-Seq we found that several TCRs were clearly biased in favor of the conventional or Treg lineages, but that a large fraction of TCRs were found in both these lineages. Finally, we found that recirculating/resident Tregs in the thymus are not monomorphic, but are composed of multiple distinct subsets and that these RT-Tregs express the most diverse TCR repertoire of all CD4SP thymcocytes. Thus, our studies define multiple stages of Treg differentiation within the thymus, and serve as a resource for future studies on CD4+ thymocyte development and Treg differentiation.
Project description:Mast cells are phenotypically and functionally highly heterogeneous, and their state is possibly controlled by their local microenvironment. Therefore, concrete analyses are needed to understand whether mast cells act as powerful motivators or dispensable bystanders in specific diseases. Here, we evaluated the correlation between synovial mast cells and rheumatoid arthritis (RA) disease severity, and the efficacy of therapeutic interventions against mast cells. We showed that degranulation of mast cells in inflammatory synovial tissues of RA patients was induced via MAS-related G protein-coupled receptor X2 (MRGPRX2), and the expression of MHC class II (MHC II) and costimulatory molecules on mast cells were upregulated. These unique signaling response led to mast cell activation and promoted T cell responses, resulting in the progression of RA. Collagen-induced arthritis mouse models treated with a combination of anti-IL-17A and cromolyn sodium, a mast cell membrane stabilizer, showed significantly reduced clinical severity and decreased bone erosion. The findings of the present study suggest that synovial microenvironment-influenced mast cells contribute to RA and may provide a novel mast cell-targeting therapy for RA.
Project description:Mast cells are tissue resident granulocytes which are most abundant at the interface between tissues and the external environment, such as around blood vessels, in the skin or mucosal surfaces in the lungs and gut. Pathologically they are involved in allergic reactions and anaphylaxis, however they may also play protective roles in responses to some infections, particularly to pathogenic helminths. Mast cells also express high levels of the IL-33 receptor, which like TLRs, activates Myd88 dependent signalling pathways to drive de novo cytokine production in mast cells.IL-33 is a member of the IL-1 family known to stimulate a number of immune cell types including mast cells. IL-33 is a strong activator of de novo cytokine production in mast cells without inducing degranulation, although it has also been shown to synergise with other signals to promote degranulation. Bone Marrow-Derived Mast cells (BMMCs) were cultured as described previously [27]. Briefly, bone marrow was flushed in PBS and the cells pelleted by centrifugation. Cells were cultured at 1 million cells per ml in RPMI 1640 supplemented with 10% FBS (Biosera/Labtech), 5 mM l‐Glutamine (GIBCO Life Technologies), 100 U/ml Penicillin (GIBCO Life Technologies), 100 μg/ml Streptomycin (GIBCO Life Technologies), 25 mM HEPES (Lonza), 1 mM sodium pyruvate (Lonza), 1X nonessential amino acids (Lonza), 50 μM 2‐mercaptoethanol and 30 ng/ml IL‐3 (PeproTech). Cells were passaged twice per week and used between passage 12 and 16. 4 independent BMMC cultures were either stimulated with 10 ng/ml IL-33 for 48 hours or left unstimulated, followed by single shot LC-MS analysis.