Phenotypic and Functional Analysis of Peripheral Mononuclear Cells During Long-Duration Space Flight

Objectives

The hypotheses of this experiment were: (1) phenotypic and functional alterations in peripheral immune cells obtained immediately after landing accurately reflect changes induced during space flight and (2) space flight-induced suppression of immune function is mediated via alterations in specific cytokines and immunomodulatory factors. Therefore the objectives of this experiment were: (1) to determine the phenotypic alterations in circulating immune cell subpopulations which occur during space flight and compare them to those observed immediately after flight, (2) to assess the functional changes in the peripheral immune cells resulting from space flight, and (3) to determine the roles of specific cytokines in mediating space flight-induced immune suppression.

Shuttle-Mir Missions
STS-71

Approach
This experiment investigated the effects of long-duration space flight on the immune system's cells. Blood samples were collected from Mir-18 crewmembers. From these samples, white blood cells were stained for specific surface markers and analyzed with the flow cytometer; percentages of the different types of white blood cells present in the circulation was determined. Functional capacity of monocytes, natural killer cells, and T-cells was determined to assess the effects of microgravity on the responses of these cells to a challenge. Cytokines were collected from the supernatants of these functional assays to determine if any alterations occurred in the response mechanisms. Messenger RNA (mRNA) was measured as an indicator of cytokine gene transcription. In addition, cytokines were measured in the serum of the collected blood samples to determine if proper amounts of these chemicals were being produced in the body.

Results
No results from PI. Not published yet.

Earth Benefits
This experiment was aimed to understand the changes in human immune cells after long-duration space flight. This improves the general knowledge of how the immune system could respond to stressful environments.

Publications
None available at this time.

Principal Investigators
Clarence Sams, Ph.D.
NASA/Johnson Space Center

Irina Konstantinova, M.D.
Institute of Biomedical Problems, Russia

Co-Investigators
Richard T. Meehan, M.D.
Duane L. Pierson, Ph.D.

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Page last updated: 07/16/1999