Gene, Immune and Cellular Responses to Single and Combined Space Flight Conditions - A (TripleLux-A) - 11.04.14
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Long-term space missions present a number of risks for astronauts. Some effects of the space environment level appear to act at the cellular level and it is important to understand the underlying mechanisms of these effects. This project uses a rat macrophage cell line to focus on two aspects of cellular function which may have medical importance: i) The synergy between the effects of the space radiation environment and microgravity on cellular function and, ii) The impairment of immune functions under spaceflight conditions.
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Sponsoring Space Agency
European Space Agency (ESA)
Earth Benefits, Scientific Discovery
ISS Expedition Duration
September 2014 - March 2015
Previous ISS Missions
The aim of Triplelux-A is to understand the mechanisms at the cellular level which underlie the following phenomena previously observed in spaceflight:
- Impairment of immune functions under spaceflight conditions.
- Enhancement of responses to radiation in microgravity.
- Clearly separate the effects of microgravity from other spaceflight factors by use of an onboard 1g centrifuge.
The Triplelux-A experiment uses the reactive oxygen burst as a measure of the phagocytic activity of macrophages and hemocytes under spaceflight conditions.
The reactive oxygen burst is measured by a chemiluminescent assay where Oxygen (O2)-radicals convert luminol to 3-Aminophthalate, which results in the emission of light at a wavelength of 475 nm. Light emission is enhanced by the addition of exogenous hydrogen peroxide. The luminol reaction is catalyzed by peroxidase.
The TRIPLELUX biosensor test is used to analyze cellular responses by a bioluminescent or chemiluminescent reporter. This is used for in-flight measurements of gene expression (SOS lux reporter) and phagocytosis. Using an onboard 1g centrifuge and a stepwise changing of g-level from 1g to microgravity, and vice versa, it is possible to determine whether changes in these processes are caused by microgravity, radiation, or a combination of both- as well as detecting a threshold at which immune cells can sense microgravity. Furthermore, the cellular adaptation to microgravity as well as the re-adaptation to 1g is to be analyzed.
Conducting studies of the immune system during spaceflight provides knowledge and understanding of the effects of space habitation on the immune system. The data from these studies is used in assessing the cellular mechanisms underlying the aggravation of radiation responses, and impairment of immune functions, during spaceflight. Understanding such risks is essential in maintaining the health and performance of crew members during long-duration missions.
With greater understanding of the immune system in space, scientists can determine new countermeasures for people suffering from weakened immune systems.
This experiment should be performed using the same batch of reagents and cells as the flight experiment, following the actual flight sequence. In case it is impossible to perform a near simultaneous ground reference, a postflight ground control duplicating the flight sequence is acceptable.
- Upload: Culture Tubes (with cells) and Luminol/Peroxidase/Zymosan Liquid reservoirs in NASA Cold Stowage (CS) (at -80°C). HM Interface plates (with culture medium) at ambient, max 7 days;
- On-orbit stowage in BIOLAB Temperature Control Unit at -20°C for the HM I/F plates (with culture medium) and the Liquid reservoirs (Back-up scenario: NASA Cold Stowage (CS));
- On-orbit stowage in NASA CS at -80°C for the Culture Tubes; Max stowage time of Culture Tubes in frozen stowage below -78°C on-orbit 4 months;
- The cells are thawed at ambient temperature (+18-28°C) for ~50 minutes, then the experiment is run at +37°C in BIOLAB. Following a preincubation (reconstitution) period of ~30 minutes, the cells are incubated for ~3 hours with a mixture of zymosan, peroxidase, and luminol. The chemiluminescence associated with the phagocytosis of the zymosan particles is measured. One set of samples is run under Zero-g and a second set under 1-g.
Ground Based Results Publications
Rabbow E, Rabbow E, Rettberg P, Rettberg P, Baumstark-Khan C, Horneck G. The SOS-LUX-LAC-FLUORO-Toxicity-test on the International Space Station (ISS). Advances in Space Research. 2003; 31(6): 1513-1524.
The Advanced Experimental Containment (AEC) hardware for the TripleLux experiments. Image courtesy of ESA.
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