New York, Jan 26 (IANS): Those would-be astronauts who made a beeline to apply for a one-way trip to Mars scheduled in 2022, boost your immunity first.

Growing up on the space shuttle may weaken your immune system, says an alarming study.

“It's well established that spaceflight affects immune responses,” said Deborah Kimbrell, a researcher in the department of molecular and cellular biology in University of California's C Davis College of Biological Sciences.

With funding from the NASA, the researchers sent Drosophila flies - which share many fundamentals of the immune system with mammals such as mice and humans - into space as eggs on a 12-day mission aboard the Space Shuttle Discovery.

After they returned to Earth, Kimbrell and team tested their responses to two different infections - a fungus which flies fight off through a pathway mediated by the Toll receptor and a bacterial infection that flies resist through a gene called Imd ('immune deficiency').

While the response through the Imd pathway was robust, the Toll pathway was 'non-functional' in space-raised flies, the study said.

In earth-based experiments, the researchers found that when flies' resistance to the fungus was improved, heir Toll pathway was boosted.

The team hopes to carry out future research with flies on the International Space Station.

Both the Toll and Imd pathways have counterparts in humans and other mammals.

The 2011 Nobel Prize in physiology and medicine was awarded to Bruce Beutler, Jules Hoffmann and Ralph Steinman for the discovery of Toll receptor activation of innate immunity in flies and mammals.