T cell aging and exhaustion: Mechanisms and clinical implications

T cell senescence and exhaustion represent critical aspects of adaptive immune system dysfunction, with profound implications for health and the development of disease prevention and therapeutic strategies. These processes, though distinct, are interconnected at the molecular level, leading to impaired effector functions and reduced proliferative capacity of T cells. Such impairments increase susceptibility to diseases and diminish the efficacy of vaccines and treatments. Importantly, T cell senescence and exhaustion can dynamically influence each other, particularly in the context of chronic diseases. A deeper understanding of the molecular mechanisms underlying T cell senescence and exhaustion, as well as their interplay, is essential for elucidating the pathogenesis of related diseases and restoring dysfunctional immune responses. This knowledge will pave the way for the development of targeted therapeutic interventions and strategies to enhance immune competence. This review aims to summarize the characteristics, mechanisms, and disease associations of T cell senescence and exhaustion, while also delineating the distinctions and intersections between these two states to enhance our comprehension.