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Space travel alters gene expression in white blood cells, weakening the immune system


June 22, 2023

Dr. Guy Trudel“A weaker immunity increases the risk of infectious diseases, limiting astronauts’ ability to perform their demanding missions in space.” - Dr. Guy TrudelThe expression of (mostly protein-coding) genes in white blood cells changes rapidly when astronauts reach the International Space Station, according to research led by Drs. Odette Laneuville and Guy Trudel published in Frontiers of Immunology

This may explain why astronauts appear more susceptible to infectious diseases while in space. Astronauts on board the International Space Station commonly suffer from skin rashes, as well as respiratory and non-respiratory diseases. 

The researchers found most genes returned to their typical pre-flight level of expression within a few weeks to one year after landing, suggesting that Earth-level gravity is required for astronauts’ immune system to function optimally. The authors hypothesized that the change in gene expression of white blood cells under microgravity is triggered by ‘fluid shift,’ where blood plasma is redistributed from the lower to the upper part of the body, including the lymphatic system. 

In a previous study, the researchers found that patients in bed for prolonged durations also underwent rapid white blood cell gene expression changes, which would explain their vulnerability to infection. Read the full press release.

“A weaker immunity increases the risk of infectious diseases, limiting astronauts’ ability to perform their demanding missions in space. If an infection or an immune-related condition was to evolve to a severe state requiring medical care, astronauts while in space would have limited access to care, medication, or evacuation,” said Dr. Guy Trudel, rehabilitation physician and researcher at The Ottawa Hospital and professor the University of Ottawa.

Authors: Daniel Stratis, Guy Trudel, Lynda Rocheleau, Martin Pelchat, Odette Laneuville

Funders: The Canadian Space Agency. Research at The Ottawa Hospital is possible because of generous donations to The Ottawa Hospital Foundation

The Ottawa Hospital is a leading academic health, research and learning hospital proudly affiliated with the University of Ottawa and supported by The Ottawa Hospital Foundation.