The Effects of Long-Term Exposure to Microgravity on Salivary Markers of Innate Immunity (Salivary Markers) - 07.14.16
The Effects of Long-Term Exposure to Microgravity on Salivary Markers of Innate Immunity (Salivary Markers) investigation involves the collection of blood, saliva, urine and a health assessment on six subjects pre-, in- and post-flight to determine if spaceflight induced immune system dysregulation increases infection susceptibility or poses a significant health risk to crewmembers onboard the International Space Station. The investigation utilizes a longitudinal, repeated measures design to determine the effects of long-term exposure to microgravity on a host of salivary antimicrobial proteins (AMPs), latent viral reactivation, antibacterial properties of saliva, and blood markers associated with innate host immune defense.
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Information Pending Experiment Details
OpNom: Salivary Markers
Richard J. Simpson, Ph.D., Department of Health and Human Performance, Houston, TX, United States
Brian E. Crucian, Ph.D., Wyle Laboratories, Houston, TX, United States
Thomas W. Lowder, Ph.D., Department of Health and Human Performance, University of Houston, Houston, TX, United States
Mark S. Clarke, Ph.D., University of Houston/JSC Space Center, Houston, TX, United States
Guillaume Spielmann, Ph.D., University of Houston, Houston, TX, United States
Daniel O' Connor, PhD., Houston, TX, United States
Duane L. Pierson, Ph.D., Johnson Space Center, Houston, TX, United States
Satish K. Mehta, Ph.D., Enterprise Advisory Services Incorporated, Houston, TX, United States
NASA Johnson Space Center, Human Research Program, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
NASA Research Office - Human Research Program (NASA Research-HRP)
Earth Benefits, Scientific Discovery, Space Exploration
ISS Expedition Duration
September 2013 - March 2016; March 2016 - September 2016
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- Future space exploration missions are dependent on a robust immune system to minimize the risk of infection among crewmembers. It is not known if the immune system is impaired during long-duration (i.e., several months vs. weeks) spaceflight because previous research in this area has been restricted to short-duration spaceflight missions. Also, because the effects of spaceflight on immunity have been assessed using blood and saliva samples collected from crewmembers immediately after returning to Earth, it is not known if these observed changes in immune function are due to prolonged periods in space or whether they are due to the stressors associated with landing. It is therefore important to collect blood, urine and saliva samples during spaceflight (i.e., on the International Space Station) so that the true effects of spaceflight on the human immune system can be determined. This research study will be important to determine if any risks to crewmembers exist as a result of impaired immunity.
- Blood, urine and saliva samples will be collected before, during and after long-duration missions to the ISS. These samples will be used to measure markers of latent viral reactivation (a global indicator of immune impairment and infection risk) in conjunction with salivary antimicrobial proteins and immune cell functional assays. As we will collect our samples during flight and return these to Earth for analysis, we will be able to determine if any changes in immune function occur during flight that could leave the crewmember at an increased risk of infection and illness.
This research study will help identify if there are any risks of an adverse health event in crewmembers due to an impaired immune system. Maintaining a robust immune system during prolonged spaceflight missions (i.e., to other planets or asteroids) will be important to ensure mission success. If any impairments in immunity are found due to spaceflight, this will allow us to develop appropriate countermeasures to help mitigate the risks.
The goal of the Salivary Markers study is to determine if spaceflight induced immune system dysregulation increases infection susceptibility or poses a significant health risk to crewmembers onboard the International Space Station. Immune system dysregulation has been documented during and after spaceflight, but it is not known if these changes increase infection susceptibility or pose a significant health risk to crewmembers. Inherent problems with current in-flight research are small sample sizes and the difficulty to control for the many confounding factors that impact on the immune system. As such, it is not known if changes in immunity are due to the microgravity environment per se, or to the stressors associated with landing and re-adaptation to the 1G environment. The present project will utilize a longitudinal repeated measures design to determine the effects of long-term exposure to microgravity on a host of salivary antimicrobial proteins (AMPs), latent viral reactivation, antibacterial properties of saliva, and blood markers associated with innate host immune defense, whilst also considering the impact of other acute stressors such as Soyuz landing. Saliva, urine and blood samples will be collected from crewmembers selected for ISS missions and ground-based controls pre-flight (L-180 and L-60 days), at “early”, “mid” and “late” phases during the approximately 5-6 month period on the ISS, and up to R+63 days after return to Earth. Subjects on yearlong missions will collect two “midpoint” samples. Saliva sampling was selected as the primary source because it is an excellent biological fluid with which to detect broad-spectrum biomarkers of front-line host immune defense and is suitable for the spaceflight environment. Attempts will also be made to establish relationships between salivary and cellular immune markers, viral reactivation and other stressors associated with spaceflight (i.e., mood state disturbances, circadian desynchronization, sleep loss/disruption, stress biomarkers) using serial data. Blood samples will be used for monocyte, NK-cell and neutrophil phenotype and functional assays. This project will help to establish if spaceflight alters innate immune function, which is important to determine if altered immunity poses a significant risk of an adverse health event among crewmembers. Moreover, these data will serve as a foundation for future countermeasure developments and technological advances to detect real time changes in immune function during subsequent lunar or Mars missions.
The data obtained from this study will serve as a foundation for future countermeasure developments and technological advances to detect real time changes in immune function during subsequent lunar or Mars Missions.
The data collected during this investigation may lead to a greater understanding of how the immune system is affected by different factors from stress to the environment. This data could potentially be used to help develop new treatments and preventative measures for immune dysfunctions.
Operational Requirements and Protocols
Decadal Survey Recommendations
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