As a new era in crewed space exploration approaches, with long-duration missions to the Moon and Mars for the coming decades, scientists are investigating how space could negatively impact astronauts’ immune systems.

In particular, a team from the Karolinska Institute in Sweden investigated how the microgravity experienced by space travelers might affect T cells. T cells are a type of white blood cell called lymphocyte that are crucial in fighting disease.

The team’s findings may help explain why any change in space in astronauts’ T cells persists on Earth. Such long-term changes can cause T cells to become less active and less effective at fighting infection, leaving astronauts vulnerable to the reappearance of latent viruses.

This will likely be something space agencies will want to know when they start sending humans to non-Earth locations. For example, NASA is currently looking into a future that includes Moon and even Martian rovers. The Artemis 3 mission, which includes the first woman and black human, is expected to send a crew to the moon in 2025. Future efforts could bring humans to the Martian surface by the early 2030s, according to the agency.

“If astronauts want to perform safe space missions, we need to understand how this affects their immune systems and try to find ways to counteract harmful changes,” said Lisa Westerberg, lead author of the study and chief scientist at the Karolinska Institutet Division. . Microbiology, tumor and cell biology were specified in the statement. “We were now able to investigate what happens to T cells, a key component of the immune system, when they are exposed to weightless conditions.”

Instead of conducting their experiments in space, Westerberg and his team brought some space to Earth. They used a custom-made waterbed that made the body think it was weightless; this technique was called “dry immersion”.

Eight healthy subjects were subjected to immersion in dry water for 3 weeks. The researchers performed blood tests of these subjects at different time intervals: before the experiment, seven, 14, and 21 days after the start of the experiment, and finally one week after the end of the experiment.

They found that the subjects’ T cells changed in response to dry immersion, mostly in terms of “gene expression,” or simply changes in which genes were active and which were inactive. This gene expression changed significantly at 7 and 14 days after weightlessness, but the most extreme change occurred after 14 days.

The T cells’ genes also seemed to adopt a more “immature” state during the process; which means they pretend not to be exposed to viruses or other diseases. This is something that can have negative health consequences.

“The T cells are starting to look like so-called naïve T cells that have not yet encountered any intruders. This could mean that they take longer to activate and are therefore less effective at fighting tumor cells and infections.” Carlos Gallardo Dodd, research co-head and postdoctoral researcher in the Karolinska Institutet Department of Microbiology, Tumor and Cell Biology, said:

However, after 21 days of exposure to microgravity, the subjects’ T cells were found to adapt to weightlessness and gene expression in the cells returned to near-normal levels. But 7 days after the experiment ended, the team found that some of the initial changes in gene expression due to weightlessness had actually returned.

Now the team of scientists will attempt to use the sounding rocket platform at the Esrange Space Center in Sweden to further study T cells and the effects of zero gravity on their functions.

“Our findings may pave the way for new treatments that reverse these changes in the genetic programming of immune cells,” said Dodd.

The team’s research was published Aug. 25 in the journal Science Advances. Source