T cells have long been known as the core of adaptive immunity and play pivotal roles in host defense (Zhu et al., 2010). There are two main types of T cells in our body, cytotoxic T cells (CD8+) and helper T (Th) cells (CD4+), the latter comprised of Th1, Th2, Th17, and Treg subsets. Increasing evidence supports that metabolic reprogramming of T cells leads to dramatic changes in tissue microenvironments, which may alter whole-body energy homeostasis and metabolism, beyond their roles in adaptive immunity (Varanasi et al., 2020).
