Premature thymic functional senescence is a hallmark of childhood acute lymphoblastic leukemia survivorship

T-cell senescence: Unlocking the tumor immune "Dark Box" - A multidimensional analysis from mechanism to tumor immunotherapeutic intervention

Immunosenescence is the dysfunction of the immune system that occurs with age, a process that is complex and characterized by several features, of which T-cell senescence is one of the key manifestations. In the tumor microenvironment, senescent T cells lead to the inability of tumor cells to be effectively eliminated, triggering immunosuppression, which in turn affects the efficacy of immunotherapy. This is a strong indication that T-cell senescence significantly weakens the immune function of the body, making individuals, especially elderly patients with cancer, more vulnerable to cancer attacks. Despite the many challenges, T-cell senescence is important as a potential therapeutic target. This review provides insights into the molecular mechanisms of T-cell senescence and its research advances in patients with cancer, especially in older adults, and systematically analyzes potential intervention strategies, including molecular mechanism-based interventions, the use of immune checkpoint inhibitors, and CAR-T cell therapy. It is hoped that this will establish a theoretical framework for T-cell senescence in the field of tumor immunology and provide a scientific and prospective reference basis for subsequent in-depth research and clinical practice on senescent T cells.

Poor Diet Quality is Associated with Premature Senescence of the Immune System in Survivors of Childhood Acute Lymphoblastic Leukaemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer. Contributory factors such as inflammation and oxidative stress, in response to drug therapies, may induce premature aging and cellular senescence with a severe impact on cardiometabolic health. Premature immunoaging through cellular senescence can lead to lower thymic output of T-cell lymphocytes translated into lower circulating T-cell receptor excision circles (TRECs). We hypothesized TRECs levels are associated with diet quality and impacted by oxidative and inflammatory status in survivors of childhood ALL (cALL). Adolescents and young adults cALL survivors from the PETALE cohort (n = 241, 22.1 ± 6.3 years at diagnosis, 49.4% males) were assessed for TREC levels and adherence to six diet quality indexes. Healthy Diet Indicator (HDI) was associated with TREC levels (β = 50.0, p = 0.005, adjusted p = 0.03). Interleukin-6 (IL-6) and C-reactive protein (CRP) were found negatively associated with TREC levels (β = -80 and -80.1, p = 0.017 and 0.026, respectively) HDI. Further analysis revealed IL-6 and CRP to be moderating factors, but not mediators, of the association between HDI and TRECs. This study supports a positive impact of a healthy diet on premature aging of the immune system in survivors of cALL and unveils the moderating role of inflammation in this association.

Ferroptosis and immunosenescence in colorectal cancer

Colorectal cancer (CRC), ranked as the globe's third leading malignancy. Despite advancements in therapeutic approaches, the mortality rate remains distressingly high for those afflicted with advanced stages of the disease. Ferroptosis is a programmed form of cell death. The ways of ferroptosis mainly include promoting the accumulation of cellular ROS and increasing the level of cellular Labile iron pool (LIP). Immunosenescence is characterized by a gradual deterioration of the immune system's ability to respond to pathogens and maintain surveillance against cancer cells. In CRC, this decline is exacerbated by the tumor microenvironment, which can suppress the immune response and promote tumor progression. This paper reviews the relationship between iron prolapse and immune senescence in colorectal cancer, focusing on the following aspects: firstly, the different pathways that induce iron prolapse in colorectal cancer; secondly, immune-immune senescence in colorectal cancer; and lastly, the interactions between immune senescence and iron prolapse in colorectal cancer, e.g., immune-immune senescent cells often exhibit increased oxidative stress, leading to the accumulation of ROS, and consequently to lipid peroxidation and induction of iron-induced cell death. At the same time, ferroptosis induces immune cell senescence as well as alterations in the immune microenvironment by promoting the death of damaged or diseased cells and leading to the inflammation usually associated with it. In conclusion, by exploring the potential targets of ferroptosis and immune senescence in colorectal cancer therapy, we hope to provide a reference for future research.