SEP 25, 2019 12:00 PM PDT

Your Immune Response Varies from AM to PM

WRITTEN BY: Kara Marker

“My biological clock is ticking.”

We’ve heard people say this phrase - maybe even said it ourselves - but what do we mean exactly? Often this is a reference to a female of reproductive age. For example, you might hear a woman say her “biological clock” is “ticking” when referencing the limited amount of healthy years for a female to become pregnant and give birth. However, the biological clock can also be a reference to circadian rhythm.

The circadian rhythm is the body’s internal clock that influences activities like waking and sleeping in response to environmental cues like light in the morning and darkness in the evening. The circadian rhythm is both natural and subject to change by a person’s environment, like a paramedic who adapts to work at night and sleep during the day. This internal clock also affects more than just sleeping and waking; eating, body temperature, and hormone product is also under the influence of circadian rhythm, thus linking it to metabolic and hormonal health conditions.

Twenty thousand neurons of the “suprachiasmatic nucleus” (SCN) in the hypothalamus of the brain make up this internal clock. A new study from scientists at the Douglas Research Centre, the Maisonneuve-Rosemont Hospital Research Centre, and McGill University found that the same clock plays a role in how well the immune system responds to external foes. 

More specifically, they observed that CD8 T cells function differently at different times during the day, something that makes a significant difference in the context of sensitive clinical administrations, like vaccines.

CD8 T cells are immune cells produced in the thymus that express a CD8 receptor (like CD4 T cells express CD4 receptors). CD8 T cells are often called cytotoxic T cells for their ability to target and destroy infected and cancerous cells.

The study included a post-vaccination mouse model to observe how the immune response changed with and without a functional circadian rhythm. Scientists found that the strength of CD8 T cell response varied during different time points throughout the day, excluding experimental mice who were missing certain genes linked to the circadian rhythm. For example, the response to the vaccine was not as strong during the day as it was at night

“Identifying the mechanisms through which the biological clock modulates the T cell response will help us better understand the processes that regulate optimal T cell responses,” explained one of the study’s scientists, Nathalie Labrecque, Ph.D. “This knowledge will contribute to improving vaccination strategies and cancer immune therapies.”

Sources: McGill University, Proceedings of the National Academy of Sciences, National Institute of General Medical Sciences, British Society for Immunology

 

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
AUG 13, 2019
Health & Medicine
AUG 13, 2019
Blood-Brain Barrier Impairment and Its Role in Alzheimer's Disease
In healthy people, the blood-brain barrier (BBB), which is fromed by brain endothelial cells, strictly controls the entrance of harmful materials into...
AUG 04, 2019
Immunology
AUG 04, 2019
New Research In Reversing Deafness
Hair cells inside the human ear are responsible for sensing and relaying sound to the brain.  In all mammals except humans, these cells can regenerate...
SEP 27, 2019
Immunology
SEP 27, 2019
Diseases We Share with Our Canine Companions: Autoimmune Encephalitis in Dogs
Like humans, dogs can develop autoimmune encephalitis, and it’s common - mostly affecting smaller breeds and young adult dogs. Now scientists underst...
DEC 20, 2019
Neuroscience
DEC 20, 2019
Does Having Herpes Increase Your Risk for Alzheimer's?
Around 44 million people around the world have Alzheimer’s disease, a progressive form of dementia that leads to memory loss and a decline in cogniti...
DEC 31, 2019
Genetics & Genomics
DEC 31, 2019
Should the Scientist Behind World's First Gene Edited Babies be in Prison?
He Jiankui, the scientist behind the world’s first gene-edited babies in 2018, has been sentenced to three years in prison by Chinese authorities for...
FEB 21, 2020
Drug Discovery & Development
FEB 21, 2020
New Antibiotics Found Using AI Technology
Using AI, researchers at MIT have found a powerful new antibiotic capable of killing some of the most dangerous drug-resistant bacteria known to man. ...
Loading Comments...