Article image

Sleep may be the best strategy to boost your immune system

New research from the ​​Institute of Medical Psychology sheds light on how good quality sleep can strengthen your body’s immune system. 

The scientists examined how sleep affects the movement of immune cells called T-cells. They studied healthy adults, tracking their sleep and taking blood samples at different times. This allowed the experts to compare T-cell movement after a good night’s sleep versus no sleep. 

The team also investigated whether hormones influenced by sleep, such as growth hormone and prolactin, had any impact on T-cell movement.

T-cells help the immune system

T-cells are a type of white blood cell that fights infection. They can’t stay in one place all the time; they need to move around the body to find and fight problems. 

The movement of the cells is not random. Special chemicals called chemokines act like signals, guiding T-cells to specific areas. These areas are often lymph nodes, which are the centers for immune response. Here, T-cells can interact with other immune cells and learn to recognize threats.

T-cell movement 

Moving around involves several steps. First, T-cells sense the chemokine signals. This tells them where to go. 

The T-cells then change shape and stick to the walls of blood vessels and tissues. This allows them to crawl towards the signal. Finally, they leave the bloodstream and enter the tissues where they’re needed.

Constantly searching for infection

The ability of T-cells to move is vital for the immune system to work properly. By traveling throughout the body, T-cells can constantly search for infection. If they find a threat, they can start an immune response

In simpler terms, T-cell movement is like sending out scouts to different parts of the body. These scouts (T-cells) follow signals (chemokines) to find important locations (lymph nodes) where they can learn about enemies (infections) and fight back to protect the body.

Selective influence on T-cell migration

“Our results show that sleep promotes the migratory potential of various T-cell subpopulations,” said Professor Luciana Besedovsky. 

During sleep, the T-cells become more adept at navigating towards special chemokines called CCL19. These CCL19 efficiently direct the T-cells to lymph nodes. Notably, the experts found that sleep specifically targets this CCL19-directed movement, not enhancing responses to other inflammatory signals.

This suggests that sleep isn’t simply giving the immune system a general boost. Instead, sleep appears to act as a fine-tuning mechanism. This targeted approach allows the body to mount a more strategic and organized defense against infections

Hormone production during sleep

When we sleep, our bodies release several hormones that help us stay healthy and grow. Two of these hormones, growth hormone and prolactin, are produced in much larger amounts during deep sleep. 

The researchers found that presence of these hormones further increased the movement of T-cells towards CCL19. 

Growth hormone

Growth hormone, needed for building and fixing tissues, increases significantly during deep sleep. This hormone is produced by the hypothalamus, a part of the brain that controls sleep itself. 

If we don’t get enough sleep, our body might not make enough growth hormone, which can hinder growth in children and overall health in adults.  


Prolactin is another hormone connected to sleep. This one reaches its highest levels during REM sleep, the stage when we dream. 

Prolactin is involved in functions like metabolism, immunity, and brain development. Just like growth hormone, prolactin production is linked to sleep cycles, so poor sleep can affect the amount of prolactin our body makes.

Sleep for a stronger immune system 

The research suggests that sleep is important for a strong immune system. Sleep controls the levels of hormones which in turn affects how well the body fights infections. This is especially important for vaccines, which need the body to create T-cells. 

“Our results also have potential clinical implications. Thus, growth hormone and prolactin could be considered as new adjuvants to promote immune responses following vaccination, especially in aged people, who typically display reduced levels of these hormones during sleep,” explained Dr Besedovsky.

The study is published in the journal Brain, Behavior, and Immunity.


Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and


News coming your way
The biggest news about our planet delivered to you each day