Functional and metabolic dichotomy of murine γδ T cell subsets in cancer immunity.

γδ T cells can display a plethora of immune functions, but recent studies have highlighted their importance, in multiple disease models, as sources of the pro-inflammatory cytokines, interleukin 17A (IL-17) and interferon γ (IFN-γ). These are produced by distinct murine effector γδ T cell subsets that diverge during thymic γδ T cell development. Among the multiple roles these subsets play in peripheral tissues, a striking dichotomy has emerged at tumour sites: whereas IFN-γ+ γδ T cells inhibit tumour cell growth, IL-17+ γδ T cells promote tumour progression and metastasis formation. In this review, we discuss the main lines of evidence, mostly from pre-clinical studies in mouse models, for this functional dichotomy in cancer immunity. We further highlight very recent advances in our understanding how metabolic sources and pathways can impact on the balance between IFN-γ+ and IL-17+ γδ T cells in the tumour microenvironment, which opens a new exciting avenue to explore towards the application of γδ T cells in cancer immunotherapy. This article is protected by copyright. All rights reserved.