In a new study, BioClock researcher Ward Vleeshouwers demonstrates that the time at which the immune system first comes into contact with an antigen, for example, through vaccination, influences the immune response. The study was carried out in mice and shows that the biological clock plays an important role in building long-term protection.
How do T-cells work?
T-cells are immune cells that help fight infections. When they first encounter a pathogen, they can develop into roughly two types of cells:
- Effector T-cells: these spring into action immediately to fight an infection.
- Memory T cells: these remain in the body for a long time and ‘remember’ the pathogen. This enables the immune system to respond much more quickly in the event of a subsequent infection.
Memory T cells are therefore very important for long-term protection, for example following vaccination.
The timing of vaccination matters
The researchers observed that mice vaccinated during their active phase produced memory T cells that differentiated differently from those of mice vaccinated during their resting phase. For mice, the active phase is at night.
This effect also led to stronger protection against a subsequent viral infection. Mice that received a COVID-19 vaccine during their active phase subsequently had a stronger T-cell response to the virus. Their immune system was therefore better prepared for the infection.
Internal clock of immune cells
The researchers discovered that this effect is governed by the biological clock of dendritic cells. These cells activate the immune system and transmit signals to T cells.
The internal clock of dendritic cells regulates the production of the protein CD70. This protein helps determine how memory T-cells develop and what properties they acquire. In this way, the biological clock directly influences the formation of immunological memory.
New insights
This study helps researchers better understand how the biological rhythm influences the immune system and shows that the timing of vaccination can be an important factor in the quality of the immune response. The results may lead to follow-up research in humans, and the findings could potentially also be applied to other vaccines, including cancer vaccines.
For both doctors and researchers, these results highlight that the timing of treatment is a key factor! A growing body of research shows that the time at which a treatment is administered can influence the outcome. By taking the body’s biological clock into account when developing and administering treatments, these may work even more effectively in the future.
Read the full scientific article here.
