Study shows that defense cells from elderly people with a history of endurance training are more efficient against inflammation
By Maria Fernanda Ziegler
In addition to muscles, lungs and heart, the immune system is also strengthened with regular physical exercise. This is what a study carried out with elderly people with a history of exercise training found. endurance –prolonged physical activity, such as long running, cycling, swimming, rowing and walking. By analyzing the defense cells of these individuals, an international team of researchers found that they were more adaptable, less inflammatory and metabolically more efficient.
The research, by Fapesp and in the magazine Scientific Reportsinvestigated the cells natural killer (NK), a type of white blood cell (lymphocyte) capable of destroying infected and diseased cells, such as cancer cells, which are on the front line of the immune system, detecting and fighting viruses and other pathogens. The cells of 9 individuals with an average of 64 years of age were analyzed, divided into untrained and trained, practitioners of endurance.
“In a previous study we had found that obesity and a sedentary lifestyle can trigger a process of premature aging of defense cells. This made us want to investigate the other side of this story, that is, whether an elderly person, practicing endurance exercise for over 20 years, can have their immune system better prepared. And in fact that is what we found. In these individuals, NK cells worked better in the face of an inflammatory challenge, in addition to using energy more efficiently. Therefore, it is as if exercise also trains the immune system.”said , visiting researcher at Justus Liebig University Giessen, in Germany.
The work is the result of de Minuzzi’s research and is part of a larger research project led in Brazil by researchers from Unesp (Universidade Estadual Paulista) and Fapesp.
According to the results, regular exercise training endurance over the years modulates the inflammatory response. “When comparing the cells of trained elderly people with those of non-athlete individuals of the same age, we found that those who had a history of endurance exercise had fewer inflammatory markers and more anti-inflammatory markers. This means that, compared to non-athlete elderly people, they had much better control of inflammation”said, professor at the Faculty of Science and Technology (FCT-Unesp), Presidente Prudente (SP) campus, and project coordinator.
Lira highlights that the immune system can be influenced by several factors, such as quality of sleep, diet, vaccination, as well as stress, sedentary lifestyle and use of immunosuppressive medications (which reduce the action of defense cells): “Physical exercise is one of those factors that can benefit the immune system and in this research project we are able to investigate how it can modulate the immune response over time.”
Changes in the cell
In the work, in addition to analyzing the phenotype of NK cells, their function on inflammatory stimulus and mitochondrial metabolism, the researchers also exposed the expanded NK cells of trained and untrained elderly people to different pharmacological blockers, such as propranolol and rapamycin.
“Trained elderly people demonstrate more efficient and adaptable immunity, with greater metabolic control and less propensity to cellular exhaustion. Regular physical exercise appears to positively modulate both adrenergic sensitivity and the cells’ energy sensor, promoting a more balanced and less inflammatory response to external stimuli”said Minuzzi.
Propranolol is a medication that blocks the adrenergic pathway – the neural and endocrine circuit that releases neurotransmitters such as adrenaline and noradrenaline – and was used to isolate the role of this activation/mobilization pathway in NK cells. Rapamycin, on the other hand, acts by inhibiting another signaling pathway: mTORC1, related to the control of cell growth and proliferation. In the study, rapamycin altered the phenotype of NK cells and, at a high dose (100 ng/mL), decreased expansion in vitro.
“In both cases, even with the blocking of signaling pathways, NK cells from trained elderly people were able to maintain immune function, while cells from untrained individuals showed cellular exhaustion or failure in the inflammatory response. This means that training endurance long-standing association with protective ‘immunometabolic’ adaptations in elderly NK. In other words, the cells become more mature and effective, less senescent and metabolically more prepared to respond to inflammatory or pharmacological stressors”, says the researcher.
Inflammatory response
In , the same group of researchers compared the immune response of young and master athletes before and after an acute exercise session. To do this, they analyzed data from whole blood and peripheral blood mononuclear cells (PBMCs) – the mononuclear fraction of the blood formed by lymphocytes and monocytes, which includes NK – from 12 master athletes (with an average of 52 years old and more than 20 years of continuous training) and young athletes with an average age of 22 and more than 4 years dedicated to training.
The results showed that master athletes had a more controlled inflammatory response compared to younger athletes. When the athletes’ blood cells were stimulated with pathogen (LPS), both groups showed increased production of IL-6 – a cytokine that signals inflammation. However, this increase was more pronounced in young people. “Another important inflammatory cytokine, TNF-α [fator de necrose tumoral alfa]it was only increased in young people”says the researcher.
While young athletes demonstrated a more intense inflammatory response, older athletes presented a more regulated and controlled profile, which suggests, according to the researchers, that lifelong training can promote a beneficial and more balanced immunological adaptation.
“As they train regularly, their bodies are used to dealing with inflammatory episodes, which requires more intense stimuli to generate significant inflammatory responses in the long term. This is the type of ‘training’ that adapts the immune system over time, making it stronger”stated Minuzzi.
Minuzzi highlights that, once again, research into immune cells from athletes with a long training history has shown that staying physically active for decades seems “to train” the regulation of inflammation: “The system does not fail to respond, but avoids exaggerations. This is particularly interesting for a greater understanding of healthy aging, as disordered inflammatory responses are linked to several chronic diseases”.
The article Natural killer cells from endurance-trained older adults show improved functional and metabolic responses to adrenergic blockade and mTOR inhibition can be read. The article Differential inflammatory responses to acute exercise and ex vivo immune challenge in young and master athletes can be read.
Text originally published in .
