Reduced naïve T cell numbers correlate with increased low-grade systemic inflammation during ageing and can be modulated by physical activity / Un número reducido de células T vírgenes se correlaciona con un aumento de la inflamación sistémica de bajo grado durante el envejecimiento y puede ser modulado por la actividad física

SUMMARY: Age-associated decline of immune system, termed immunosenescence, is characterized by low-grade systemic inflammation, known as inflammaging, together with T-cell functional dysregulation. Although affecting all individuals, different environmental as well genetic factors impinge on the individual´s susceptibility or resilience to immunosenescence. Physical activity has been shown to improve autonomy and functionality in older adults. However, if physical activity affects immunosenescence or inflammaging remains unknown. The purpose of this study was to analyze immunosenescence and inflammaging in elderly individuals by measuring peripheral naïve T cells and interleukin (IL) -6 from peripheral blood and evaluate the impact of physical activity on T cell dysregulation and inflammaging. Thirty (30) elderly volunteers (10 males and 20 females), and 7 young controls (2 males ad 7 females), were recruited for this study. A methodology questionnaire was used to evaluate different parameters such as physical activity, and peripheral naïve CD4+ and CD8+ T cells and serum IL-6 were measured by FACS and ELISA respectively. Our results shown that naïve T cells decline, and IL-6 levels increase as older people age. Interestingly, we observed strong negative correlation between naïve T cells numbers and IL-6 levels in older adults, suggesting a direct link between reduced naïve T cell pool and increased inflammaging. Continuous physical activity during youth did not affect immunosenescence and inflammaging in elderly, but physical activity during elderly increase naïve T cell numbers and reduce inflammaging in older subjects. Our results showed reduced number of naïve T cells and increased levels of IL-6 as elder people get older. Moreover, the strong negative correlation between these parameters suggest that naïve T cells can have a direct suppressive activity over innate immune components. Furthermore, physical activity during elderly can reduce immunosenescence and inflammaging in older subjects.

RESUMEN: El deterioro del sistema inmunológico asociado con la edad, denominado inmunosenescencia, se caracteriza por una inflamación sistémica de bajo grado, conocida como inflamaging, junto con una desregulación funcional de las células T. Aunque afectan a todos los individuos, diferentes factores ambientales y genéticos inciden en la susceptibilidad o resiliencia del individuo a la inmunosenescencia. Estudios anteriores han demostrado que la actividad física mejora la autonomía y la funcionalidad en los adultos mayores, aunque como la actividad física impacta a la inmunosenescencia e inflammaging es aún desconocido. El propósito de este estudio fue analizar la inmunosenescencia e inflammaging en personas de edad avanzada, midiendo las células T vírgenes y la interleucina (IL)-6 de sangre periférica, junto con evaluar el impacto de la actividad física sobre la inflamación basal y la inmunosenescencia. Treinta voluntarios ancianos (10 hombres y 20 mujeres) y 7 controles jóvenes (2 hombres y 5 mujeres) fueron incluidos en este estudio. Para medir actividad física, autonomía y dependencia se utilizó un cuestionario de metodología, junto con evaluar el número de células T CD4+ y CD8+ periféricas vírgenes e IL-6 sérica mediante FACS y ELISA, respectivamente. Nuestros resultados muestran que las células T vírgenes disminuyen y los niveles de IL-6 aumentan a medida que las personas mayores envejecen. Curiosamente, observamos una fuerte correlación negativa entre el número de células T vírgenes y los niveles de IL-6 en adultos mayores, lo que sugiere un vínculo directo entre la reducción de la reserva de células T vírgenes y el aumento de la inflamación. La actividad física durante la juventud no afectó la inmunosenescencia ni la inflamación en los ancianos, pero la actividad física durante la vejez aumenta el número de células T vírgenes y reduce la inflamación en los adultos mayores. Estos resultados sugieren que inmunosenescencia e inflammaging parecen estar directamente conectados, además de concluir que el desarrollo de actividad física durante la vejez reduce la inmunosenescencia y la inflamación basal en adultos mayores.

Immunosenescence: participation of T lymphocytes and myeloid-derived suppressor cells in aging-related immune response changes / Imunosenescência: participação de linfócitos T e células mieloides supressoras nas alterações da resposta imune relacionadas ao envelhecimento

ABSTRACT Healthy aging is partly related to appropriate function of the immune system. As already reported, some changes in this system are observed, including reduced number and repertoire of T cells due to thymic involution, accumulation of memory T cells by chronic infections, homeostatic proliferation compensating for the number of naïve T cells, decreased proliferation of T cells against a stimulus, telomere shortening, replicative senescence of the T cells, and inflammaging, besides the accumulation of myeloid-derived suppressor cells. The purpose of this article is to clarify each of these changes, aiming to minimize limitations of immunosenescence. If such associations can be established, these cells may be used as early and less invasive markers of aging-related diseases, as well as to indicate interventions, evaluate the efficacy of interventions and be a tool to achieve longevity with quality of life.

RESUMO O envelhecimento saudável está relacionado, pelo menos em parte, com a função adequada do sistema imunológico. Isso porque já foi relatado que, com o envelhecimento, algumas mudanças desse sistema são observadas, como a diminuição da percentagem e do repertório de células T pela involução tímica, acúmulo de células T de memória por infecções crônicas, compensação do número de células T naïve por proliferação homeostática, diminuição da capacidade de proliferação das células T frente a um estímulo, encurtamento dos telômeros, senescência replicativa das células T, e inflammaging, além do acúmulo de células mieloides supressoras. Este artigo visa esclarecer cada uma das mudanças, mencionadas, com o intuito de buscar meios de minimizar as limitações da imunosenescência. Caso seja possível estabelecer tais relações, essas células podem ser utilizadas como marcadores precoces e pouco invasivos de doenças relacionadas ao envelhecimento, além da possibilidade de serem utilizadas para indicar intervenções, avaliar a eficácia das intervenções e como ferramenta para alcance da longevidade com qualidade de vida.

Manipulación de la inmunosenescencia / Immunosenescence manipulation

En la actualidad existe un aumento del envejecimiento poblacional en Cuba y a nivel mundial, consecuencia del éxito de las políticas de salud pública y del desarrollo socioeconómico. Con el incremento progresivo de la edad se evidencian cambios en el sistema inmunológico que contribuyen a una susceptibilidad incrementada a las enfermedades infecciosas, condiciones patológicas relacionadas con la inflamación, enfermedades autoinmunes, el cáncer y se manifiesta una respuesta reducida ante la vacunación. La manipulación de la inmunosenescencia a través de diferentes terapéuticas se espera que contribuya al rejuvenecimiento del sistema inmune y por consiguiente a la restauración de la inmunidad en individuos inmunocomprometidos, al control del cáncer y al incremento de la eficacia de la vacunación en ancianos(AU)

There is an increase of population aging in Cuba and globally, as a result of the success of public health policies and socio-economic development. With the progressive increase in age, there are changes in the immune system that contribute to an increased susceptibility to infectious diseases, pathological conditions related to inflammation, autoimmune diseases, cancer and a reduced response to vaccination. The manipulation of immunosenescence through different therapies has been studied. It is expected to possibly contribute to the 'rejuvenation' of the immune system and consequently, to the restoration of immunity in immunocompromised individuals, the improvement of the effectiveness of vaccination in the elderly and the control of cancer(AU)

Immune System Dysfunction in the Elderly

ABSTRACT Human aging is characterized by both physical and physiological frailty that profoundly affects the immune system. In this context aging is associated with declines in adaptive and innate immunity established as immunosenescence. Immunosenescence is a new concept that reflects the age-associated restructuring changes of innate and adaptive immune functions. Thus elderly individuals usually present chronic low-level inflammation, higher infection rates and chronic diseases. A study of alterations in the immune system during aging could provide a potentially useful biomarker for the evaluation of immune senescence treatment. The immune system is the result of the interplay between innate and adaptive immunity, yet the impact of aging on this function is unclear. In this article the function of the immune system during aging is explored.