RESUMO
El timo es un órgano linfoide central o primario localizado en la parte anterosuperior del tórax. Constituye el principal sitio de diferenciación y maduración de las células T. En esta revisión se detallan aspectos actuales de la embriología, la histología y la función tímica y en la generación de los diferentes subtipos de timocitos y su diferenciación a células T maduras efectoras, la inducción de las células T tímicas reguladoras involucradas en el mantenimiento de la tolerancia a lo propio y la involución que sufre este órgano durante el proceso de inmunosenescencia
Thymus is a primary organ located in the antesuperior area of the torax. It is the principal place of differentiation and maduration of T cells. In this review present aspects of the embriology, histology and thymic function are detailed, as well as its role in the generation of different kinds of thymic cells; its differentiation to mature cells and of regulator T cells has a crucial role in tolerance induction. Moreover, thymic involution during of immunosenescence process is shown
Assuntos
Humanos , Organogênese/fisiologia , Síndrome de DiGeorge/história , Timo/fisiopatologia , EnvelhecimentoRESUMO
El timo es un órgano linfoide central o primario localizado en la parte anterosuperior del tórax. Constituye el principal sitio de diferenciación y maduración de las células T. En esta revisión se detallan aspectos actuales de la embriología, la histología y la función tímica y en la generación de los diferentes subtipos de timocitos y su diferenciación a células T maduras efectoras, la inducción de las células T tímicas reguladoras involucradas en el mantenimiento de la tolerancia a lo propio y la involución que sufre este órgano durante el proceso de inmunosenescencia(AU)
Thymus is a primary organ located in the antesuperior area of the torax. It is the principal place of differentiation and maduration of T cells. In this review present aspects of the embriology, histology and thymic function are detailed, as well as its role in the generation of different kinds of thymic cells; its differentiation to mature cells and of regulator T cells has a crucial role in tolerance induction. Moreover, thymic involution during of immunosenescence process is shown(AU)
Assuntos
Humanos , Organogênese/fisiologia , Timo/fisiopatologia , Síndrome de DiGeorge/história , EnvelhecimentoRESUMO
Age-related biological deterioration also includes immune system deterioration and, in consequence, a rise in the incidence and prevalence of infections and cancers, as well as low responses to vaccination strategies. Out of all immune cell subsets, T-lymphocytes seem to be involved in most of the age-related defects. Since T-lymphocytes mature during their passage through the thymus, and the thymus shows an age-related process of atrophy, thymic regression has been proposed as the triggering event of this immune deterioration in elderly people. Historically, it has been accepted that the young thymus sets the T-lymphocyte repertoire during the childhood, whereupon atrophy begins until the elderly thymus is a non-functional evolutionary trace. However, a rising body of knowledge points toward the thymus functioning during adulthood. In the elderly, higher thymic function is associated with a younger immune system, while thymic function failure is associated with all-cause mortality. Therefore, any new strategy focused on the improvement of the elderly quality of life, especially those trying to influence the immune system, should take into account, together with peripheral homeostasis, thymus function as a key element in slowing down age-related decline.
