1. |
- Georganaki, Maria, et al.
(author)
-
Tumor endothelial cell up-regulation of IDO1 is an immunosuppressive feed-back mechanism that reduces the response to CD40-stimulating immunotherapy
- 2020
-
In: Oncoimmunology. - : TAYLOR & FRANCIS INC. - 2162-4011 .- 2162-402X. ; 9:1
-
Journal article (peer-reviewed)abstract
- CD40-stimulating immunotherapy can elicit potent anti-tumor responses by activating dendritic cells and enhancing T-cell priming. Tumor vessels orchestrate T-cell recruitment during immune response, but the effect of CD40-stimulating immunotherapy on tumor endothelial cells has not been evaluated. Here, we have investigated how tumor endothelial cells transcriptionally respond to CD40-stimulating immunotherapy by isolating tumor endothelial cells from agonistic CD40 mAb- or isotype-treated mice bearing B16-F10 melanoma, and performing RNA-sequencing. Gene set enrichment analysis revealed that agonistic CD40 mAb therapy increased interferon (IFN)-related responses in tumor endothelial cells, including up-regulation of the immunosuppressive enzyme Indoleamine 2, 3-Dioxygenase 1 (IDO1). IDO1 was predominantly expressed in endothelial cells within the tumor microenvironment, and its expression in tumor endothelium was positively correlated to T-cell infiltration and to increased intratumoral expression of IFN gamma. In vitro, endothelial cells up-regulated IDO1 in response to T-cell-derived IFN gamma, but not in response to CD40-stimulation. Combining agonistic CD40 mAb therapy with the IDO1 inhibitor epacadostat delayed tumor growth in B16-F10 melanoma, associated with increased activation of tumor-infiltrating T-cells. Hereby, we show that the tumor endothelial cells up-regulate IDO1 upon CD40-stimulating immunotherapy in response to increased IFN gamma-secretion by T-cells, revealing a novel immunosuppressive feedback mechanism whereby tumor vessels limit T-cell activation.
|
|
2. |
- Sun, Michelle T., et al.
(author)
-
Meta-Analysis of Intraocular Bleeding With Dual Antiplatelet Therapy Using P2Y12 Inhibitors Prasugrel or Ticagrelor
- 2020
-
In: American Journal of Cardiology. - : EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC. - 0002-9149 .- 1879-1913. ; 125:8, s. 1280-1283
-
Research review (peer-reviewed)abstract
- Intraocular bleeding is a devastating clinical event due to its potentially blinding nature. It is not known if determine if dual antiplatelet therapy using aspirin and potent P2Y12 inhibitors increases this risk. We searched MEDLINE and ClinicalTrials.gov for randomized controlled trials that were phase III, randomly assigned patients to dual antiplatelet therapy with either aspirin and a potent P2Y12 inhibitor or aspirin and clopidogrel, had follow-up of 6 months, and at least 200 patients. Corresponding authors were contacted for intraocular bleeding data. Inverse-variance, weighted, fixed-effects meta-analysis was undertaken, with random-effects meta-analysis performed as a sensitivity analysis. Four trials enrolling 42,850 patients were included. The median follow-up ranged from 12 to 14 months. There was overall low risk of bias. Pooled analysis demonstrated no statistically significant increase in the risk of intraocular bleeding with dual antiplatelet therapy using potent P2Y12 inhibitors compared with clopidogrel (risk ratio 0.89, 95% confidence interval 0.58 to 136). There was no significant heterogeneity observed across trials (I-2 statistic 0%, p = 0.98). The use of random-effects meta-analysis did not change the effect estimate or confidence intervals, and the results appeared similar when stratified by potent P2Y12 inhibitor (p = 0.97). In conclusion, this collaborative meta-analysis of dual antiplatelet trials does not suggest that the risk of intraocular bleeding is increased with the use of potent P2Y12 inhibitors compared with clopidogrel. Our results suggest that these potent P2Y12 inhibitors may continue to be used cautiously where indicated as part of dual antiplatelet therapy, even in those at high risk of spontaneous intraocular bleeding. Crown Copyright (C) 2020 Published by Elsevier Inc. All rights reserved.
|
|