Age-related regression of the thymus is associated with a decline in naïve T cell output. This is thought to contribute to the reduction in T cell diversity seen in older individuals and linked with increased susceptibility to infection, autoimmune disease, and cancer. Thymic involution is one of the most dramatic and ubiquitous changes seen in the aging immune system, but the mechanisms which underlying this process are poorly understood. However, a picture is emerging, implicating the involvement of both extrinsic and intrinsic factors. In this review we assess the role of the thymic microenvironment as a potential target that regulates thymic involution, question whether thymocyte development in the aged thymus is functionally impaired, and explore the kinetics of thymic involution.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3791471 | PMC |
http://dx.doi.org/10.3389/fimmu.2013.00316 | DOI Listing |
Mol Oncol
January 2025
Molecular Carcinogenesis Group, Department of Histology and Embryology, Medical School, National and Kapodistrian University of Athens, Greece.
Rejuvenation of elementary immune system components has emerged as a promising strategy to deal with increased susceptibility to infections, cancers, autoimmune disorders, and low efficacy to vaccines, frequently accompanying aging. In this context, the thymus has gained significant attention. A recent study by Santamaria et al.
View Article and Find Full Text PDFJ Leukoc Biol
January 2025
Department of Biochemistry and Microbiology, Faculty of Science, University of Victoria, Victoria BC, Canada.
The thymus is a primary lymphoid organ where major types of T lymphocytes undergo essential developmental processes. Eosinophils are among the cell types present in microenvironments within the thymus, and perhaps surprisingly, the role of thymic eosinophils, especially during homeostatic conditions, remains unclear. Major physiological events impact thymic organization and function throughout life: including age-related involution, pregnancy, and exposure to chemotherapy or radiation.
View Article and Find Full Text PDFVaccines (Basel)
November 2024
Department of Biological Sciences, Kean University, Union, NJ 07083, USA.
Immunosenescence, a systematic reduction in the immune system connected with age, profoundly affects the health and well-being of elderly individuals. This review outlines the hallmark features of immunosenescence, including thymic involution, inflammaging, cellular metabolic adaptations, and hematopoietic changes, and their impact on immune cells such as macrophages, neutrophils, T cells, dendritic cells, B cells, and natural killer (NK) cells. Thymic involution impairs the immune system's capacity to react to novel antigens by reducing thymopoiesis and shifting toward memory T cells.
View Article and Find Full Text PDFNat Rev Immunol
January 2025
Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
Despite its importance for generating and maintaining a healthy and broad T cell repertoire, the thymus is exquisitely sensitive to acute damage. Marked thymic involution occurs in response to stimuli as diverse as infection, stress, pregnancy, malnutrition, drug use and cytoreductive chemotherapy. However, the thymus also has a remarkable capacity for repair, although this regenerative capacity declines with age.
View Article and Find Full Text PDFLife Sci
January 2025
3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics of University of Minho; Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine; Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory; Braga/Guimarães, Portugal. Electronic address:
Aims: The development and selection of T cells occur within the thymus. This organ involutes throughout life, compromising the generation of T cells and, consequently, the efficacy of the immune system. Mesenchymal stem cells (MSC) have beneficial effects on the immune system.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!