Identification of blood vessels mediating lymphocyte entry into tumors during cancer immunotherapy
Channel: IPBS-Toulouse
Date: 2022-02-09

Cancer Treatment : Immunotherapy, a therapeutic strategy aiming to increase the activity of the immune system in order to eliminate cancer cells, has revolutionized cancer treatment over the past decade. A better understanding of how this therapeutic approach is working, and more specifically, how lymphocytes access tumors during cancer immunotherapy, could improve the efficacy of this treatment. The team of Jean-Philippe Girard, Inserm Research Director at the Institute of Pharmacology and Structural Biology (French National Center for Scientific Research [CNRS]/Université Toulouse III - Paul Sabatier), in collaboration with Gustave Roussy, has recently discovered the essential role of specific blood vessels known as tumor-associated high endothelial venules (TA-HEVs) in this process. For the first time, the scientists were able to film the lymphocytes infiltrating the tumors via TA-HEVs. Furthermore, the researchers have shown in animal models that increasing the proportion of HEV vessels in tumors improves the efficacy of cancer immunotherapy and leads to tumor regressions. Finally, they found that therapeutic response to cancer immunotherapy is highly increased when a large number of HEV  blood vessels are present in tumors from patients with metastatic melanoma (skin cancer). This study has been published in the February 3, 2022 issue of Cancer Cell.