Quality sleep enhances the functionality of the immune system: Study

A team led by Professor Luciana Besedovsky from the Institute of Medical Psychology has demonstrated that sleep promotes the potential of immune cells – so-called T cells – to migrate toward lymph nodes.

Sleep increases the directed migration of T cells toward a signaling protein, the so-called ‘homing’ chemokine CCL19. This molecule mediates the migration of T cells, which possess the corresponding receptor for CCL19, to the lymph nodes, where the T cell immune defenses are ‘trained’ by being presented with antigens – for example, after a vaccination.

The research, published in the journal Brain, Behavior, and Immunity, showed that in people who slept after a vaccination, the immune response was twice as strong on average as in people who did not sleep during the night after the vaccination.

The scientists conducted multiple examinations on the concentration of different subgroups of T cells in the blood of a group of healthy individuals over two 24-hour periods. During one condition, participants slept for eight hours at night, while during the other, they stayed awake while resting in bed at night. Blood was then collected and analyzed.

Analysis of the blood samples revealed significant differences between the test conditions: “Our results show that sleep promotes the migratory potential of various T-cell subpopulations,” said Besedovsky.

Further experiments demonstrated that incubating T cells with plasma from sleeping participants similarly enhanced their migratory capabilities. “This demonstrates that soluble factors that are elevated in blood plasma during sleep mediate the effect of sleep on T-cell migration. So we can in a way recreate the effect of sleep in the lab using the blood plasma of sleeping persons,” reported Besedovsky.

Scientists also identified growth hormone and prolactin as the decisive factors for this migration behavior. Both hormones showed sleep-dependent changes in concentration in the plasma, with higher values among the participants who slept during the night.

“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.” concluded Besedovsky.

Reference: Estefanía Martínez-Albert, Nicolas D. Lutz, Robert Hübener, Stoyan Dimitrov, Tanja Lange, Jan Born, Luciana Besedovsky; Journal: Brain Behavior and Immunity; DOI: 10.1016/j.bbi.2024.02.021