328 research outputs found
Role of 4-1BB Ligand in Costimulation of T Lymphocyte Growth and its Upregulation on M12 B Lymphomas by cAMP
K46J B lymphomas express a T cell costimulatory activity that is not inhibited by CTLA-4Ig, anti-B7-1, anti-B7-2, anti-intercellular adhesion molecule 1 or antibodies to heat stable antigen. In this paper we report that this costimulatory activity is mediated at least in part by 4-1BB ligand, a member of the tumor necrosis factor (TNF) gene family that binds to 4-1BB, a T cell activation antigen with homology to the TNF/nerve growth factor receptor family. A fusion protein between 4-1BB and alkaline phosphatase (4-1BB-AP) blocks T cell activation by K46J lymphomas in both an antigen-specific system and with polyclonally (anti-CD3) activated T cells. 4-1BB-AP also blocks antigen presentation by normal spleen cells. When the antigen-presenting cells express B7 molecules as well as 4-1BB ligand, we find that B7 molecules and 4-1BB-AP both contribute to T cell activation. These data suggest that 4-1BB ligand plays an important role in costimulation of IL-2 production and proliferation by T cells. The B lymphoma M12 expresses low levels of 4-1BB-L but can be induced to express higher levels by treatment of the B ceils with cAMP, which also induces B7-1 and B7-2 in these cells. Thus cAMP appears to coordinately induce several costimulatory molecules on B cells
Targeting 4-1BB and PD-L1 induces potent and durable antitumor immunity in B-cell lymphoma
IntroductionAlthough PD-1/L1 mAb has demonstrated clinical benefits in certain cancer types, low response rate and resistance remain the main challenges for the application of these immune checkpoint inhibitors (ICIs). 4-1BB is a co-stimulator molecule expressed in T cells, which could enhance T cell proliferation and activation. Herein, the synergetic antitumor effect and underlying mechanism of 4-1BB agonist combined with PD-1/PD-L1 blockade were determined in B-cell lymphoma (BCL).MethodsSubcutaneous transplantation BCL tumor models and metastasis models were established to evaluate the therapeutic effect of PD-L1 antibody and/or 4-1BB agonist in vivo. For the mechanistic study, RNA-seq was applied to analyze the tumor microenvironment and immune-related signal pathway after combination treatment. The level of IFN-γ, perforin, and granzyme B were determined by ELISA and Real-time PCR assays, while tumor-infiltrating T cells were measured by flow cytometry and immunohistochemical analysis. CD4/CD8 specific antibodies were employed to deplete the related T cells to investigate the role CD4+ and CD8+ T cells played in combination treatment.ResultsOur results showed that combining anti-PD-L1 ICI and 4-1BB agonists elicited regression of BCL and significantly extended the survival of mice compared to either monotherapy. Co-targeting PD-L1 and 4-1BB preferentially promoted intratumoral cytotoxic lymphocyte infiltration and remodeled their function. RNA-sequence analysis uncovered a series of up-regulated genes related to the activation and proliferation of cytotoxic T lymphocytes, further characterized by increased cytokines including IFN-γ, granzyme B, and perforin. Furthermore, depleting CD8+ T cells not CD4+ T cells totally abrogated the antitumor efficacy, indicating the crucial function of the CD8+ T cell subset in the combination therapy.DiscussionIn summary, our findings demonstrated that 4-1BB agonistic antibody intensified the antitumor immunity of anti-PD-1/PD-L1 ICI via promoting CD8+ T cell infiltration and activation, providing a novel therapeutic strategy to BCL
Automatic segmentation of multiple cardiovascular structures from cardiac computed tomography angiography images using deep learning.
OBJECTIVES:To develop, demonstrate and evaluate an automated deep learning method for multiple cardiovascular structure segmentation. BACKGROUND:Segmentation of cardiovascular images is resource-intensive. We design an automated deep learning method for the segmentation of multiple structures from Coronary Computed Tomography Angiography (CCTA) images. METHODS:Images from a multicenter registry of patients that underwent clinically-indicated CCTA were used. The proximal ascending and descending aorta (PAA, DA), superior and inferior vena cavae (SVC, IVC), pulmonary artery (PA), coronary sinus (CS), right ventricular wall (RVW) and left atrial wall (LAW) were annotated as ground truth. The U-net-derived deep learning model was trained, validated and tested in a 70:20:10 split. RESULTS:The dataset comprised 206 patients, with 5.130 billion pixels. Mean age was 59.9 ± 9.4 yrs., and was 42.7% female. An overall median Dice score of 0.820 (0.782, 0.843) was achieved. Median Dice scores for PAA, DA, SVC, IVC, PA, CS, RVW and LAW were 0.969 (0.979, 0.988), 0.953 (0.955, 0.983), 0.937 (0.934, 0.965), 0.903 (0.897, 0.948), 0.775 (0.724, 0.925), 0.720 (0.642, 0.809), 0.685 (0.631, 0.761) and 0.625 (0.596, 0.749) respectively. Apart from the CS, there were no significant differences in performance between sexes or age groups. CONCLUSIONS:An automated deep learning model demonstrated segmentation of multiple cardiovascular structures from CCTA images with reasonable overall accuracy when evaluated on a pixel level
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Machine Learning Framework to Identify Individuals at Risk of Rapid Progression of Coronary Atherosclerosis: From the PARADIGM Registry.
Background Rapid coronary plaque progression (RPP) is associated with incident cardiovascular events. To date, no method exists for the identification of individuals at risk of RPP at a single point in time. This study integrated coronary computed tomography angiography-determined qualitative and quantitative plaque features within a machine learning (ML) framework to determine its performance for predicting RPP. Methods and Results Qualitative and quantitative coronary computed tomography angiography plaque characterization was performed in 1083 patients who underwent serial coronary computed tomography angiography from the PARADIGM (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging) registry. RPP was defined as an annual progression of percentage atheroma volume ≥1.0%. We employed the following ML models: model 1, clinical variables; model 2, model 1 plus qualitative plaque features; model 3, model 2 plus quantitative plaque features. ML models were compared with the atherosclerotic cardiovascular disease risk score, Duke coronary artery disease score, and a logistic regression statistical model. 224 patients (21%) were identified as RPP. Feature selection in ML identifies that quantitative computed tomography variables were higher-ranking features, followed by qualitative computed tomography variables and clinical/laboratory variables. ML model 3 exhibited the highest discriminatory performance to identify individuals who would experience RPP when compared with atherosclerotic cardiovascular disease risk score, the other ML models, and the statistical model (area under the receiver operating characteristic curve in ML model 3, 0.83 [95% CI 0.78-0.89], versus atherosclerotic cardiovascular disease risk score, 0.60 [0.52-0.67]; Duke coronary artery disease score, 0.74 [0.68-0.79]; ML model 1, 0.62 [0.55-0.69]; ML model 2, 0.73 [0.67-0.80]; all P<0.001; statistical model, 0.81 [0.75-0.87], P=0.128). Conclusions Based on a ML framework, quantitative atherosclerosis characterization has been shown to be the most important feature when compared with clinical, laboratory, and qualitative measures in identifying patients at risk of RPP
Mesoscopic transport in KSTAR plasmas: avalanches and the staircase
The self-organization is one of the most interesting phenomena in the
non-equilibrium complex system, generating ordered structures of different
sizes and durations. In tokamak plasmas, various self-organized phenomena have
been reported, and two of them, coexisting in the near-marginal (interaction
dominant) regime, are avalanches and the staircase. Avalanches
mean the ballistic flux propagation event through successive interactions as it
propagates, and the staircase means a globally ordered pattern of
self-organized zonal flow layers. Various models have been suggested to
understand their characteristics and relation, but experimental researches have
been mostly limited to the demonstration of their existence. Here we report
detailed analyses of their dynamics and statistics and explain their relation.
Avalanches influence the formation and the width distribution of the staircase, while the staircase confines avalanches within its
mesoscopic width until dissipated or penetrated. Our perspective to consider
them the self-organization phenomena enhances our fundamental understanding of
them as well as links our findings with the self-organization of mesoscopic
structures in various complex systems
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Percent atheroma volume: Optimal variable to report whole-heart atherosclerotic plaque burden with coronary CTA, the PARADIGM study.
BACKGROUND AND AIMS:Different methodologies to report whole-heart atherosclerotic plaque on coronary computed tomography angiography (CCTA) have been utilized. We examined which of the three commonly used plaque burden definitions was least affected by differences in body surface area (BSA) and sex. METHODS:The PARADIGM study includes symptomatic patients with suspected coronary atherosclerosis who underwent serial CCTA >2 years apart. Coronary lumen, vessel, and plaque were quantified from the coronary tree on a 0.5 mm cross-sectional basis by a core-lab, and summed to per-patient. Three quantitative methods of plaque burden were employed: (1) total plaque volume (PV) in mm3, (2) percent atheroma volume (PAV) in % [which equaled: PV/vessel volume * 100%], and (3) normalized total atheroma volume (TAVnorm) in mm3 [which equaled: PV/vessel length * mean population vessel length]. Only data from the baseline CCTA were used. PV, PAV, and TAVnorm were compared between patients in the top quartile of BSA vs the remaining, and between sexes. Associations between vessel volume, BSA, and the three plaque burden methodologies were assessed. RESULTS:The study population comprised 1479 patients (age 60.7 ± 9.3 years, 58.4% male) who underwent CCTA. A total of 17,649 coronary artery segments were evaluated with a median of 12 (IQR 11-13) segments per-patient (from a 16-segment coronary tree). Patients with a large BSA (top quartile), compared with the remaining patients, had a larger PV and TAVnorm, but similar PAV. The relation between larger BSA and larger absolute plaque volume (PV and TAVnorm) was mediated by the coronary vessel volume. Independent from the atherosclerotic cardiovascular disease risk (ASCVD) score, vessel volume correlated with PV (P < 0.001), and TAVnorm (P = 0.003), but not with PAV (P = 0.201). The three plaque burden methods were equally affected by sex. CONCLUSIONS:PAV was less affected by patient's body surface area then PV and TAVnorm and may be the preferred method to report coronary atherosclerotic burden
Role of TNFR-related 2 mediated immune responses in dextran sulfate sodium-induced inflammatory bowel disease
Previous work has suggested that the LIGHT-TR2 costimulatory pathway plays a role in the acute and chronic stages of dextran sulfate sodium (DSS)-induced colitis [Steinberg et al. (2008); Wang et al. (2005)]. To clarify the role of TNFR-related 2 (TR2) signaling in the maintenance of intestinal homeostasis, we generated a TR2 knock-out (KO) mouse. Using DSS to induce colitis, we compared the colitic symptoms and pathological changes in wild type (WT) and TR2 KO mice, and the production of cytokines by the diseased colons. We also studied the role of TR2 in suppressing innate and adaptive immunity in the DSS model. TR2 deficient mice were characterized by reduced symptoms of intestinal inflammation compared with wildtype mice, and reduced production of cytokines. We therefore generated a monoclonal antibody against mouse TR2 which was specific to TR2 and capable of blocking TR2 signals. With this antibody, we demonstrated that antagonizing TR2 during the development of DSS-induced colitis reduced the symptoms of inflammation. Our findings suggest that TR2 is an important mediator in colitis, and may serve as a therapeutic target in inflammatory bowel disease
Observation of B0bar --> D(*)0 p pbar
The B meson decay modes B --> D p pbar and B --> D* p pbar have been studied
using 29.4 fb^{-1} of data collected with the Belle detector at KEKB. The B0bar
--> D0 p pbar and B0bar --> D*0 p pbar decays have been observed for the first
time with branching fractions Br(B0bar --> D0 p pbar) =(1.18\pm 0.15\pm 0.16)
10^{-4} and Br(B0bar --> D*0 p pbar) =(1.20^{+0.33}_{-0.29}\pm 0.21) 10^{-4}.
No signal has been found for the B+ --> D+ p pbar and B+ --> D*+ p pbar decay
modes, and the corresponding upper limits at 90% C.L. are presented.Comment: 6 pages, 3 figures, submited to Phys. Rev. Let
Search for B^- --> J/psi Lambda p-bar decay
We report the results of a search for B^{-} \to \jpsi \Lambda \pbar based
on a data set of 78 fb data collected at the resonance
with the Belle detector at the KEKB asymmetric collider. No
substantial signal is found, and we set the branching fraction upper limit
{\cal B}(B^{-} \to \jpsi \Lambda \pbar) < 4.1 \times 10^{-5} at 90%
confidence level.Comment: 8 pages, 2 figures, submitted to Phys. Rev.
Observation of Double cc bar Production in e+ e- Annihilation at sqrt{s} ~ 10.6 GeV
We report the observation of prompt J/psi via double ccbar production from
the e+e- continuum. In this process one ccbar pair fragments into a J/psi meson
while the remaining pair either produces a bound charmonium state or fragments
into open charm. Both cases have been observed: the first by studying the mass
spectrum of the system recoiling against the J/psi, and the second by
reconstructing the J/psi together with a charmed meson. We find cross-sections
of \sigma(e+ e- -> J/psi eta_c (gamma)) * BR (eta_c -> >=4 charged) = 0.033
(+0.007 -0.006)(stat) \pm 0.009(syst)pb and \sigma(e+ e- -> J/psi D*+ X) = 0.53
(+0.19 -0.15)(stat) \pm 0.14(syst) pb, and infer \sigma(e+ e- -> J/psi c cbar)
/ \sigma(e+ e- -> J/psi X) = 0.59 (+0.15 -0.13)(stat) \pm 0.12(syst). These
results are obtained from a 46.2/fb data sample collected near the Upsilon(4S)
resonance, with the Belle detector at the KEKB asymmetric energy e+ e-
collider.Comment: 7 pages, 2 figures, to be submitted to Physical Review Letter
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