Researchers
have demonstrated the importance of good-quality sleep time and time
again, showing that a solid night’s rest can contribute to many aspects
of physical and mental well-being. One new study has explained how sleep
contributes to the proper functioning of the immune system.
Getting enough good-quality sleep each night is essential if we want to stay healthy and function well throughout the day.
Studies have shown that being sleep deprived is akin to overdrinking when it comes to its effects on the brain.
Recent research also suggests that poor sleep increases pain sensitivity and may raise the likelihood of developing cardiovascular problems.
Now,
a study recently conducted by a team from the University of Tübingen in
Germany has found a mechanism linking sleep to the functioning of the
immune system.
The researchers who led this study found that a
good night’s sleep can boost the effectiveness of certain specialized
immune cells called T cells.
In the study paper — which now appears in the Journal of Experimental Medicine — the scientists explain what lies at the core of this relationship between sleep and the body’s defenses against infection.
T cells contribute to the body’s immune response when a potentially harmful foreign body enters the system.
These
immune cells recognize pathogens then activate integrins, which are a
type of protein that allows T cells to attach to and tackle their
targets.
The researchers note that little is known about how T
cells activate integrins, as well as what may prevent these cells from
attaching to potentially compromised targets.
To learn more about
these mechanisms, the team focused on Gs alpha-coupled receptor agonists
(Gas-coupled receptor agonists). These are signaling molecules, many of
which have the ability to block the action of the immune system.
Through
laboratory analyses, they found some Gas-coupled receptor agonists that
stopped T cells from activating integrins, thus preventing them from
attaching to their targets.
The receptor agonists they
found included two hormones (called adrenaline and noradrenaline), two
proinflammatory molecules (called prostaglandin E2 and D2), and
adenosine (which is a chemical that plays a key role in cellular
signaling and energy transfer).
“The levels of these molecules
needed to inhibit integrin activation,” says study co-author Stoyan
Dimitrov, “are observed in many pathological conditions, such as tumor growth, malaria infection, hypoxia, and stress.”
Since
adrenaline and prostaglandin levels tend to drop during sleep, the
scientists chose to go one step further and study this phenomenon in
greater detail in human participants.
They took T cells from some
volunteers who slept and some who remained awake. After analyzing these
samples, Dimitrov and team saw that the T cells of sleeping people had
higher levels of integrin activation compared with the same cells taken
from people in a waking state.
So, the authors note, this
indicates that sleep has a positive impact on the correct functioning of
T cells as part of the body’s immune response, and this is thanks to
the fact that Gas-coupled receptor agonists are less active at this
time.
“Our findings show that sleep has the potential to enhance the efficiency of T cell responses, which is especially relevant in light of the high prevalence of sleep disorders and conditions characterized by impaired sleep, such as depression, chronic stress, aging, and shift work.”
Study co-author Luciana Besedovsky
In
the future, the authors hope that their results could lead to the
development of new therapies boosting T cell function, which would have
numerous applications — including in cancer immunotherapy.