It is known that people have a greater response to certain vaccines depending on the time of day at which the vaccine is administered but, until now, the reason for this has not been clearly understood.
New research from RCSI University of Medicine and Health Sciences has provided insight into the mechanism of the circadian or body clock and the role it plays in the body’s response to vaccinations.
Published in Nature Communications, the researchers examined the changes taking place in dentritic cells, which are types of immune cells that are involved in the body’s vaccine response.
The research found that the shape of the mitochondria (‘the powerhouse’) within these cells, changes at various times during the body’s 24-hour cycle and these changes influence how the cells function.
The study found that the circadian clock within dendritic cells determines whether the mitochondria forms either small pieces or long string shapes, the latter of which are more effective in the vaccine response as they have a better ability to break up the vaccine into small pieces for interaction with immune cells (T cells).
The findings shed light on a crucial aspect of the body’s response to vaccination and highlight the importance of circadian rhythms in immunity. The results could help improve the design and timing of administration of future vaccines to maximise effectiveness.
The majority of this study was supported through funding provided to Professor Annie Curtis by the Science Foundation Ireland Career Development Award (CDA) programme and by the Irish Research Council through a Laureate Award and an RCSI Strategic Academic Recruitment Programme (StAR) award.
Further support was provided by a Conacyt grant, an SFI Investigator Award and a European Research Council Consolidator Award.
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