To determine the effects of spaceflight on immune function, specifically the potential dysfunction of T-Cells

Immunosuppression has been reported in a number of previous flight experiments and ground-based studies using flight analogue systems. The potential impact of immunosuppression is increased risk of severe illness during a mission.

• This experiment was selected as a collaborative NASA/ESA experiment during the last International Space Life Sciences NRA. ESA hardware was selected to accommodate the experiment and ESA agreed to manage the development of the experiment. NASA responsibility is to provide the PI grant and consult as required.
• The experiment was launched from Baikonur on Soyuz 13S in Sept. 06. Due to an ISS experiment execution error, the experiment was conducted for only 1.5 hr. out of the 4 hours planned.
• Ground based experiments have been conducted to identify genes at 1.5hr.
• Cell number, glucose utilization, and RNA quantification have been measured and Gene array and analysis for the flight samples is complete. Real-time Reverse Transcriptase-Polymerase Chain Reaction (RTPCR) analysis of the flight samples will be done on the top 10 regulated genes in the 1.5 hr samples.

• Assess the effects of spaceflight on gene expression for 3 microbes: S. typhimurium, P. aeruginosa, and C. albicans by comparing spaceflight results with ground and modeled microgravity results.
• Assess the effects of spaceflight on the virulence potential of 3 microbes: S. typhimurium, P. aeruginosa, and C. albicans by comparing spaceflight results with ground and modeled microgravity results.

• Specifically this experiment will determine why monocyte differentiation into macrophages is severely reduced in returning astronauts.
• To determine the effect of microgravity on Protein Kinase C (PKC) regulated genes that control monocyte differentiation, the initiation of apoptosis (cell death) and cell cycle arrest.
• To fully characterize the effect of microgravity on the activation of PKC.
• To evaluate downstream signaling of PKC in response to mitogenic stimulation.

Objective:

• Identify and characterize S. pneumonia genes and proteins that are differentially expressed in low shear models and in space flight.
• Investigate the gene and protein expression patterns of known virulence genes or virulence properties for alterations due to space flight or low shear environment growth.

Relevance/Impact:

• S. pneumoniae is a commensal respiratory microbe carried by approximately 40% of the healthy population and is an opportunistic pathogen in individuals with reduced immune function.
• It is anticipated that the results from this study will advance our understanding of the virulence mechanism of this bacteria and how it adapts to different environments.

Development Approach:

• Developed a new canister/vial system to culture bacteria at +37 degrees C and then at specific time points during exponential growth, freeze a set of cultures to preserve any changes; recover frozen
  specimens for post-flight for studies.
• Launched on STS-118 (13A.1; August 8, 2007, returned August 21, 2007).
• Flight samples were returned to the PI laboratory on 8/28/07 for post flight analysis.

The Micro 2 experiment will study how gravity alters microbial  biofilm formation with the goal of developing new strategies to reduce their impact on the operation of spacecrafts and the health of their crew.

Bioflms have the potential to cause significant damage not only to spacecrafts and their crew but also to a variety of commercial and medical applications including biofouling of medical devices and in industrial settings.  A greater understanding of biofilms is essential if we are to find effective methods to combat their formation.  The proposed study has a fundamental component aimed at furthering our basic knowledge of biofilms and an applied component with the goal of testing the efficacy of novel antimicrobial coatings.