588 research outputs found

    Early Growth Response Gene-2 Controls Inflammatory Responses of CD4+ T Cells by Negatively Regulating Th17 Differentiation.

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    PhDCD4+ T cells play a central role in controlling the adaptive immune response by secreting cytokines to control the responses of different lymphocytes. Naïve CD4+ T cells differentiate into at least four subsets, Th1, Th2, Th17, and inducible regulatory T cells under antigen and corresponding cytokine microenvironment during an immune response. Therefore, each subset has unique functions for pathogen elimination. The differentiation of these subsets is induced in response to conditioned cytokine stimulation, which induces specific master regulator transcription factors. Multiple other transcription factors, both subset specific and shared, are also involved in promoting subset differentiation. Previously, our group has discovered that early growth response gene-2 (Egr-2) is important for the maintenance of T cell homeostasis and controls the development of autoimmune disease. However, the underlying mechanisms are unknown. In this study, using Egr-2 conditional knockout mice, a novel mechanism of Egr-2 in the control of Th17 differentiation has been discovered. Egr-2 is induced by TGFβ and IL-6 in naïve CD4+ T cells. The induced Egr-2 negatively regulates the expression of IL-17, the signature cytokine for Th17. In contrast, Egr-2 has less effect on the expression of IL-2 or IFN-γ in effector T cells. In the absence of Egr-2, CD4+ T cells produce high levels of Th17 cytokines. Deletion of Egr-2 in T cells renders mice susceptible to EAE induction; a model for Th17 mediated autoimmune diseases. T cells lacking Egr-2 show increased propensity for Th17, but not Th1 or Th2, differentiation in vitro. The key mechanism of Egr-2 in regulation of Th17 differentiation is to inhibit the function of Batf for transactivation of IL-17 expression and promotion of Th17 differentiation. Egr-2 interacts with Batf in CD4+ T cells and suppresses its interaction with DNA sequences derived from the IL-17 promoter, while the activation of STAT3 and expression of RORγt is unchanged in Th17 cells in the absence of Egr-2. Thus, Egr- 14 2 plays an important role to intrinsically control Th17 differentiation. We also found that CD4+ T cells from multiple sclerosis (MS) patients have reduced expression of Egr-2 and increased expression of IL-17 following stimulation with anti-CD3 in vitro. Collectively, our results demonstrate that Egr-2 is an intrinsic regulator that controls Th17 differentiation by inhibiting Batf activation which may be important for the control of inflammatory autoimmune diseases.Arthritis Research U

    Early growth response gene-2 (Egr-2) regulates the development of B and T cells

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    The study was supported by Arthritis Research UK. Copyright @ 2011 Li et al.BACKGROUND: Understanding of how transcription factors are involved in lymphocyte development still remains a challenge. It has been shown that Egr-2 deficiency results in impaired NKT cell development and defective positive selection of T cells. Here we investigated the development of T, B and NKT cells in Egr-2 transgenic mice and the roles in the regulation of distinct stages of B and T cell development. METHODS AND FINDINGS: The expression of Egr1, 2 and 3 were analysed at different stages of T and B cell development by RT-PCT and results showed that the expression was strictly regulated at different stages. Forced expression of Egr-2 in CD2+ lymphocytes resulted in a severe reduction of CD4+CD8+ (DP) cells in thymus and pro-B cells in bone marrow, which was associated with reduced expression of Notch1 in ISP thymocytes and Pax5 in pro-B cells, suggesting that retraction of Egr-2 at the ISP and pro-B cell stages is important for the activation of lineage differentiation programs. In contrast to reduction of DP and pro-B cells, Egr-2 enhanced the maturation of DP cells into single positive (SP) T and NKT cells in thymus, and immature B cells into mature B cells in bone marrow. CONCLUSIONS: Our results demonstrate that Egr-2 expressed in restricted stages of lymphocyte development plays a dynamic, but similar role for the development of T, NKT and B cells.This article is provided by the Brunel Open Access publishing fund

    Dual targeting of CD19 and CD22 with Bicistronic CAR-T cells in Patients with Relapsed/Refractory Large B Cell Lymphoma

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    Relapse following CD19-directed chimeric antigen receptor T-cells (CAR-T) for relapsed/refractory large B-cell lymphoma (r/r LBCL) is commonly ascribed to antigen loss or CAR-T exhaustion. Multi-antigen targeting and PD-1 blockade are rational approaches to prevent relapse. Here, we test CD19/22 dual-targeting CAR-T (AUTO3) plus pembrolizumab in r/r LBCL as inpatient or outpatient therapy (NCT03289455, https://clinicaltrials.gov/ct2/show/NCT03289455). Endpoints include toxicity (primary) and response rates (secondary). AUTO3 was manufactured for 62 patients using autologous leukapheresis, modified with a bicistronic transgene. 52 patients received AUTO3 (7/52,50x106; 45/52,150-450x106) and 48/52 received pembrolizumab. Median age was 59 years (range,27-83) and 46/52 had stage III/IV disease. Median follow-up was 21.6 months (range,15.1-51.3) at last data cut (Feb 28, 2022). AUTO3 was safe: grade 1-2 and grade 3 CRS affected 18/52 (34.6%) and 1/52 (1.9%) patients, neurotoxicity arose in 4 patients (2/4, grade 3-4), HLH affected 2 patients, and no Pembrolizumab-associated autoimmune sequalae were observed. On this basis, outpatient administration was tested in 20 patients, saving a median of 14 hospital days/patient. AUTO3 was effective: overall response rates were 66% (48.9%, CR; 17%, PR). For patients with CR, median DOR was not reached, with 54.4% (CI: 32.8, 71.7) projected to remain progression-free beyond 12 months after onset of remission. DOR for all responding patients was 8.3 months (95% CI: 3.0, NE) with 42.6% projected to remain progression-free beyond 12 months after onset of remission. Overall, AUTO3 +/- pembrolizumab for r/r LBCL was safe, lending itself to outpatient administration, and delivered durable remissions in 54.4% of complete responders, associated with robust CAR-T expansion. Neither dual-targeting CAR-T nor pembrolizumab prevented relapse in a significant proportion of patients, and future developments include next-generation-AUTO3, engineered for superior expansion/persistence in vivo, and selection of CAR binders active at low antigen densities

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters
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