Changes of cytokines during a spaceflight analog--a 45-day head-down bed rest

PLoS One. 2013 Oct 15;8(10):e77401. doi: 10.1371/journal.pone.0077401. eCollection 2013.

Abstract

Spaceflight is associated with deregulation in the immune system. Head-down bed rest (HDBR) at -6° is believed to be the most practical model for examining multi-system responses to microgravity in humans during spaceflight. In the present study, a 45-day HDBR was performed to investigate the alterations in human immune cell distributions and their functions in response to various stimuli. The effect of countermeasure, Rhodiola rosea (RR) treatment, was also examined. A significant decrease of interferon-γ (IFN-γ) and interleukin-17 (IL-17) productions by activated T cells, increase of IL-1β and IL-18 by activated B and myeloid cells were observed during HDBR. The upregulation of serum cortisol was correlated with the changes of IL-1 family cytokines. In addition, a significant increase of memory T and B cell and regulatory T cells (Treg) were also detected. The uptake of RR further decreased IFN-γ level and slowed down the upregulation of IL-1 family cytokines. These data suggest that for prolonged HDBR and spaceflight, the decreased protective T cell immunity and enhanced proinflammatory cytokines should be closely monitored. The treatment with RR may play an important role in suppressing proinflammatory cytokines but not in boosting protective T cell immunity.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bed Rest*
  • Cytokines / biosynthesis
  • Cytokines / blood*
  • Head*
  • Humans
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / metabolism
  • Male
  • Plant Extracts / pharmacology
  • Rhodiola / chemistry
  • Space Flight*
  • Weightlessness Simulation / methods*

Substances

  • Cytokines
  • Plant Extracts

Grants and funding

This work was supported by grants from the Natural Basic Research Program of China (2011CB711000, 2010CB945300, Q.G.), the National Natural Science Foundation of China (31070787 and 31270935, Q.G., 31171144 and 30871222, X.C.), the opening foundation of the State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center (SMFA12K08, Q.G.), Program for New Century Excellent Talents in University (NCET-10-0175/BMU20100005, Q.G.), the Research Fund for the Doctoral Program of Higher Education (20100001110049, Q.G.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.