New research shows growing evidence of the different ways travel in space’s microgravity can adversely affect the human body, and how it reduces the activity of genes in white blood cells that are important to the immune system. is taking place.
A study of 14 astronauts who spent four-and-a-half to six-and-a-half months on the International Space Station found that gene expression in these cells, also called white blood cells, declined rapidly upon reaching space, and on Earth. It was found to return to normal soon after its return, researchers said Thursday.
The findings provide insight into why astronauts are more susceptible to infections during flight, and show how the body’s systems for fighting pathogens are weakened in space.
“Weakened immunity increases the risk of infections that limit the ability of astronauts to perform the extremely demanding tasks in space. If the condition developed, astronauts would be limited in what they could do while in space, “access to care and medication,” said Odette Lanouville, a molecular biologist at the University of Ottawa in Canada. He is the lead author of a study published in . Immunology frontier.
White blood cells are produced in the bone marrow and move through the bloodstream and tissues. When it detects an invader such as a virus or bacteria, it produces antibody proteins to attack the pathogen. Specific genes control the release of such proteins.
The researchers tested white blood cells isolated from blood taken from Canadian Space Agency and NASA astronauts (11 men and 3 women), once before flight, four times on the space station, and four times on the space station. After returning to Earth, it was inspected five times.
The study found that gene expression for 247 genes in white blood cells was about one-third of normal levels while in space. This occurred within the first few days in space, but remained at steady levels thereafter. Genes typically return to normal behavior within about a month after the astronaut returns to Earth.
“White blood cells are highly sensitive to the space environment. White blood cells trade their specialized immune functions for cell maintenance and housekeeping roles. I knew, but I didn’t know the mechanism,” said the study’s co-authors. Guy Trudell, a rehabilitation medicine specialist at Ottawa Hospital, said:
The discovery of altered gene behavior in leukocytes “is an important step towards understanding human immune dysregulation in space,” Trudell added.
The altered behavior, the researchers say, could be due to a phenomenon called “fluid shift,” in which blood is redistributed from the lower part of the body to the upper part in the absence of Earth’s gravity. Increased solar radiation in space is unlikely to be the cause, the researchers added.
“We’re going to need new, concrete measures,” Trudell said.
Scientists have previously documented that astronauts experience immune dysfunction in space. This includes reactivation of latent viruses such as Epstein-Barr virus, which causes infectious mononucleosis. Causes of chickenpox, herpes zoster, and herpes zoster. Herpes simplex type 1 is the cause of cold sores.
Astronauts also release more virus particles in their saliva, urine and other bodily fluids, increasing the risk of spreading pathogens to other astronauts who may have weakened immune systems.
The study, funded by the Canadian Space Agency, announced on June 8, shows changes in the brains of NASA-funded astronauts — buffers and buffers to protect against sudden impacts and to remove waste products. It follows a study that detailed the expansion of space in the brain.
Other documented effects of space travel include bone and muscle atrophy, cardiovascular changes, inner ear balance problems, and eye syndromes.
Cancer risk from increased radiation exposure is another concern.
https://www.voanews.com/a/study-reveals-how-immune-system-of-astronauts-breaks-down-/7147877.html Study Reveals How Astronauts’ Immune Systems Disrupt