Exosomes derived from Vdelta2-T cells control Epstein-Barr virus–associated tumors and induce T cell antitumor immunity
Menée à l'aide de modèles murins de cancers associés au virus d'Epstein-Barr, cette étude met en évidence l'intérêt thérapeutique d'exosomes issus de lymphocytes T gamma delta
Epstein-Barr virus (EBV) is a common pathogen that contributes to the development of several cancers, which can be difficult to treat. γδ-T cells have innate activity and have been proposed as a cancer immunotherapy, but they have been difficult to apply, particularly because they have to be individually prepared for each patient. To overcome the hurdles associated with whole γδ-T cell–based therapy, Wang et al. isolated exosomes from a subtype of activated γδ-T cells, which contained multiple immunostimulatory molecules and cell death–inducing ligands. These exosomes were effective against multiple mouse models of EBV-associated cancers and did not require customized preparation unlike cell-based therapies.Treatment of life-threatening Epstein-Barr virus (EBV)–associated tumors remains a great challenge, especially for patients with relapsed or refractory disease. Here, we found that exosomes derived from phosphoantigen-expanded Vδ2-T cells (Vδ2-T-Exos) contained death-inducing ligands (FasL and TRAIL), an activating receptor for natural killer (NK) cells (NKG2D), immunostimulatory ligands (CD80 and CD86), and antigen-presenting molecules (MHC class I and II). Vδ2-T-Exos targeted and efficiently killed EBV-associated tumor cells through FasL and TRAIL pathways and promoted EBV antigen–specific CD4 and CD8 T cell expansion. Administration of Vδ2-T-Exos effectively controlled EBV-associated tumors in Rag2−/−γc−/− and humanized mice. Because expanding Vδ2-T cells and preparing autologous Vδ2-T-Exos from cancer patients ex vivo in large scale is challenging, we explored the antitumor activity of allogeneic Vδ2-T-Exos in humanized mouse cancer models. Here, we found that allogeneic Vδ2-T-Exos had more effective antitumor activity than autologous Vδ2-T-Exos in humanized mice; the allogeneic Vδ2-T-Exos increased the infiltration of T cells into tumor tissues and induced more robust CD4 and CD8 T cell–mediated antitumor immunity. Compared with exosomes derived from NK cells (NK-Exos) with direct cytotoxic antitumor activity or dendritic cells (DC-Exos) that induced T cell antitumor responses, Vδ2-T-Exos directly killed tumor cells and induced T cell–mediated antitumor response, thus resulting in more effective control of EBV-associated tumors. This study provided proof of concept for the strategy of using Vδ2-T-Exos, especially allogeneic Vδ2-T-Exos, to treat EBV-associated tumors.