Space is a hostile environment for humans, posing multiple health risks, including the ability to induce immune system changes during spaceflight. This immune system dysregulation can have severe consequences for space missions.
In 2021, the European Space Agency initiated the Terra Novae program, which has three destinations, including the Moon, Mars, and low Earth orbit. Next-generation astronauts associated with Terra Novae will be screened pre-flight to predict and alleviate their reactions to space conditions to ultimately preserve their well-being.
A recent study published in npj Microgravity describes how microgravity and radiation affect the immune system.
Study: Next generation of astronauts or ESA astronaut 2.0 concept and spotlight on immunity. Image Credit: Jbruiz / Shutterstock.com
Effects of space conditions on immune cells and development
Numerous studies have examined the effects of spaceflight on immune cell development. For example, monocyte progenitors and granulocytes were reduced in rodents in space or when exposed to anti-orthostatic suspension.
Likewise, one study using an amphibian model observed elevated transcription of immunoglobulin M (IgM) heavy chain and reduced expression of Ikaros, the lymphoid-determining transcription factor, thereby suggesting an impact on the development of B-cells.
Mice flown onboard a satellite for a month exhibited changes in the expression of proteins involved in immune cell and bone development in their femurs. B-cells were also reduced in the spleen and bone marrow of these mice one week after landing. Similarly, murine fetal thymus under simulated microgravity (sμG) revealed a decline in T-cell maturation stages.
One study showed increases in neutrophils upon short and long spaceflight, albeit the cells had reduced phagocytosis capacity. An increased neutrophil-lymphocyte ratio was also reported when leukocytes from healthy donors were subjected to sμG. This was also evident…