Here’s a medical mix: the space shuttle, immune systems in space, and elderly and young children here on Earth.

Onboard space shuttle Discovery’s STS-133 mission, there are sixteen rodent hitchhikers, riding in their own self-contained modules.

The mice aboard Discovery will be in orbit for 11 days, where shuttle astronauts will perform daily checks on their health and well-being. At mission’s end, within two hours of the shuttle’s return to Earth, eight of the animals will be infected with respiratory syncytial virus. Another group of mice kept in nearly identical conditions on the ground will also be exposed to the virus.

Syncytial virus is a pathogen that infects almost all human children by age two, and ordinarily causes a relatively harmless cold-like upper respiratory disease. In some children, however, the infection spreads to the lungs, where the inflammation it generates causes coughing, wheezing and extreme difficulty in breathing.

The idea behind the experiment is to probe spaceflight-induced immune-system impairment.

“Since the Apollo missions, we have had evidence that astronauts have increased susceptibility to infections during flight and immediately post-flight…they seem more vulnerable to cold and flu viruses and urinary tract infections, and viruses like Epstein-Barr, which infect most people and then remain dormant, can reactivate under the stress of spaceflight,” said Dr. Roberto Garofalo, a professor at the University of Texas Medical Branch at Galveston (UTMB).

Garofalo is principal investigator for the space experiment, an effort to discover what triggers this increased susceptibility to infection. The investigation’s goal is both of protecting the astronauts themselves and people with more vulnerable immune systems here on Earth, such as the elderly and young children.

The mouse experiment is a collaboration between teams at UTMB and NASA’s Ames Research Center in Mountain View, California. 

Unique environment

The results may well benefit those on Earth…as well as future space travelers.

Understanding how spaceflight impairs the immune system and finding ways to make sure that infection doesn’t threaten the health of space travelers are expected to become increasingly important in the future, as NASA plans human expeditions beyond the relative safety of Earth orbit — to Mars, for example, or the asteroids.

Also, the developing commercial spaceflight industry — which hopes to launch large numbers of private citizens into orbit in the near future — also has a stake in ensuring that its passengers stay safe and healthy.

Despite the shuttle program’s end, UTMB’s Garofalo said that immune system experiments in space may well continue on the International Space Station.

“The space environment incorporates many factors that we know affect the immune system — microgravity, radiation, even different nutritional standards — all acting in a relatively short period of time,” Garofalo said.

“The ISS provides a unique environment for generating answers to fundamental questions about the human immune system. Those answers will benefit people here on Earth, and there’s been a lot of interest in pursuing them, Garofalo concluded.

By LD/CSE