1. T lymphocyte recruitment to melanoma brain tumors depends on distinct venous vessels.
- Author
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Messmer, Julia M., Thommek, Calvin, Piechutta, Manuel, Venkataramani, Varun, Wehner, Rebekka, Westphal, Dana, Schubert, Marc, Mayer, Chanté D., Effern, Maike, Berghoff, Anna S., Hinze, Daniel, Helfrich, Iris, Schadendorf, Dirk, Wick, Wolfgang, Hölzel, Michael, Karreman, Matthia A., and Winkler, Frank
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IMMUNE checkpoint inhibitors , *T cells , *BRAIN tumors , *INTRACRANIAL tumors , *BRAIN metastasis - Abstract
To improve immunotherapy for brain tumors, it is important to determine the principal intracranial site of T cell recruitment from the bloodstream and their intracranial route to brain tumors. Using intravital microscopy in mouse models of intracranial melanoma, we discovered that circulating T cells preferably adhered and extravasated at a distinct type of venous blood vessel in the tumor vicinity, peritumoral venous vessels (PVVs). Other vascular structures were excluded as alternative T cell routes to intracranial melanomas. Anti-PD-1/CTLA-4 immune checkpoint inhibitors increased intracranial T cell motility, facilitating migration from PVVs to the tumor and subsequently inhibiting intracranial tumor growth. The endothelial adhesion molecule ICAM-1 was particularly expressed on PVVs, and, in samples of human brain metastases, ICAM-1 positivity of PVV-like vessels correlated with intratumoral T cell infiltration. These findings uncover a distinct mechanism by which the immune system can access and control brain tumors and potentially influence other brain pathologies. [Display omitted] • PVVs are key structures for T cell recruitment to melanoma brain tumors • Anti-PD-1/CTLA-4 inhibitors boost T cell recruitment through PVVs • T cell recruitment and antitumor immunity is dependent on ICAM-1 expression on PVVs • ICAM-1 on PVVs correlates with T cell infiltration in human melanoma brain metastases How T cells are recruited to brain tumors from the blood remains unclear. Messmer et al. identify peritumoral venous vessels (PVVs) as key structures for T cell recruitment to melanoma brain tumors. PVVs are the sites of T cell extravasation and facilitated rapid T cell migration under immune checkpoint inhibition. T cell recruitment and antitumor immunity were dependent on ICAM-1. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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