1. VISTA Expression on Cancer-Associated Endothelium Selectively Prevents T-cell Extravasation.
- Author
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Luk SJ, Schoppmeyer R, Ijsselsteijn ME, Somarakis A, Acem I, Remst DFG, Cox DT, van Bergen CAM, Briaire-de Bruijn I, Grönloh MLB, van der Meer WJ, Hawinkels LJAC, Koning RI, Bos E, Bovée JVMG, de Miranda NFCC, Szuhai K, van Buul JD, Falkenburg JHF, and Heemskerk MHM
- Subjects
- Humans, Endothelial Cells metabolism, Endothelium metabolism, Immune Checkpoint Proteins, T-Lymphocytes, B7 Antigens, Sarcoma, Synovial
- Abstract
Cancers evade T-cell immunity by several mechanisms such as secretion of anti-inflammatory cytokines, down regulation of antigen presentation machinery, upregulation of immune checkpoint molecules, and exclusion of T cells from tumor tissues. The distribution and function of immune checkpoint molecules on tumor cells and tumor-infiltrating leukocytes is well established, but less is known about their impact on intratumoral endothelial cells. Here, we demonstrated that V-domain Ig suppressor of T-cell activation (VISTA), a PD-L1 homolog, was highly expressed on endothelial cells in synovial sarcoma, subsets of different carcinomas, and immune-privileged tissues. We created an ex vivo model of the human vasculature and demonstrated that expression of VISTA on endothelial cells selectively prevented T-cell transmigration over endothelial layers under physiologic flow conditions, whereas it does not affect migration of other immune cell types. Furthermore, endothelial VISTA correlated with reduced infiltration of T cells and poor prognosis in metastatic synovial sarcoma. In endothelial cells, we detected VISTA on the plasma membrane and in recycling endosomes, and its expression was upregulated by cancer cell-secreted factors in a VEGF-A-dependent manner. Our study reveals that endothelial VISTA is upregulated by cancer-secreted factors and that it regulates T-cell accessibility to cancer and healthy tissues. This newly identified mechanism should be considered when using immunotherapeutic approaches aimed at unleashing T cell-mediated cancer immunity., (©2023 American Association for Cancer Research.)
- Published
- 2023
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