If the space damages the immune system

A group of researchers at the University of California Davis has studied the effects of microgravity space on the immune system of insects Drosophila, showing that the conditions in space can be harmful to the immune response. The results of the study can be found in PLOS ONE.


An insect Drosophila infected with a fungus.

Credit: NASA Ames Research Center)

Travel in space? An unforgettable adventure, but also a risk to the immune system. It is the result of a research group at the University of California Davis, who showed how to remain in NASA’s Space Shuttle has weakened a key function of the immune defense mechanism in insects Drosophila.

These insects, perhaps the most studied in the experiments of genetics and evolutionary biology, they share certain fundamental features of the immune system with other mammals, such as mice and even humans. And so were the ideal candidates to test the hypothesis that flying in space affects the immune response.

Thanks to some funds received from NASA, researchers have made some eggs from Drosophila aboard the Space Shuttle Discovery, in a 12-day mission. The insects take about 10 days to develop into adults: once returned to Earth scientists Davis, led by a researcher at the Department of Cell Biology and Molecular Deborah Kimbrell, and were able to observe the effects of microgravity applied on a sufficient period of time.

In particular, they studied the immune response of Drosophila that had two infections: a fungus, which usually insects fighting through a channel mediated by Toll receptors of type (a class of receptors involved in innate immunity especially), and a bacterium.

Both the Toll receptors and IMD (immune Deficiency) have their counterpart in humans and other mammals, and so the choice to observe these particular immune reactions was particularly suitable.

The analysis of insects grown in space has found that while the response was adequate through the IMD channel, the Toll channels were “non-functional”. But not only during some experiments carried out under conditions of hypergravity on Earth (the opposite of what happens in space), insect resistance to the fungus appeared even better, and then the Toll receptors functioned better than under normal conditions.


Fruit fly, Drosophila melanogaster, such as those planned for use as model organisms for variable gravity studies aboard the International Space Station.

Credit: NASA Ames Research Center)

And so it seems that a link between gravity and immune resistance exists; there is, although, a question very important for astronauts: does the prolonged stay in spacecraft have negative consequences for health?

But why microgravity impairs the immune system? Kimbrell and his group have now developed two hypotheses. First: the psychological stress. The space bugs have indeed shown high expression of genes for HSP protein produced under conditions of heat precisely as a response to psychological stress. Second possibility: the microgravity interferes with the proteins out of the cells of Drosophila in an area particularly important for channels Toll, which unlike those IMD, would be damaged.

Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *