The rhythm of the immune system | Abroad
Biology – immune cells obey that of the internal biological clock: the activity of so-called dendritic cells, which track down degenerate or foreign cells and present them to the killer cells of the immune system, is highest during periods of rest.
Unlike the innate immune system, the acquired immune system targets a specific pathogen. To do this, dendritic cells migrate to the lymph nodes, where they inform the body’s own defenses about the intruder. This process depends on the time of day and follows a 24-hour rhythm, as reported by a research team from the University of Geneva and the Ludwig Maximilians University in Munich in the journal “Nature Immunology”.
According to this, the activation of the immune system is best in the late resting phase, in nocturnal mice in the afternoon and in humans in the early morning, as researchers found out in animal experiments and in experiments with human cell cultures.
“We have identified numerous molecules, especially chemokines, that are involved in the migration process and whose expression is regulated by the internal clock,” said the head of the study, Christoph Scheiermann from the university, according to the university’s Geneva statement on Monday. Chemokines are cellular messenger substances that play a central role in the immune system.
The optimal vaccination time
Whether this daily rhythm will keep the immune system on alert when the risk of infection increases, the researchers cannot yet answer conclusively.
A British research team found evidence in an earlier study that. The severity of a viral infection depends on the time of day. According to this, herpes and influenza viruses multiplied ten times faster in nocturnal rodents if they were infected at the beginning of their resting phase. A disruption of the internal clock leads to increased virus replication and spread, the researchers wrote.
Scheiermann’s team will now try the immune response that occurs when a pathogen or vaccine enters the body. Because the timing of the administration of vaccines or immunotherapies could possibly actually influence their effectiveness, i.e. the University of Geneva.
https://www.nature.com/articles/s41590-021-01040-x