title: Immune suppression of human lymphoid tissues and cells  in rotating suspension culture and onboard the International  Space Station.
abstract: The immune responses of human lymphoid tissue explants or cells isolated from this tissue were studied quantitatively under normal gravity and microgravity. Microgravity was either modeled by solid body suspension in a rotating, oxygenated culture vessel or was actually achieved on the International Space Station (ISS). Our experiments demonstrate that tissues or cells challenged by recall antigen or by polyclonal activator in modeled microgravity lose all their ability to produce antibodies and cytokines and to increase their metabolic activity. In contrast, if the cells were challenged before being exposed to modeled microgravity suspension culture, they maintained their responses. Similarly, in microgravity in the ISS, lymphoid cells did not respond to antigenic or polyclonal challenge, whereas cells challenged prior to the space flight maintained their antibody and cytokine responses in space. Thus, immune activation of cells of lymphoid tissue is severely blunted both in modeled and true microgravity. This suggests that suspension culture via solid body rotation is sufficient to induce the changes in cellular physiology seen in true microgravity. This phenomenon may reflect immune dysfunction observed in astronauts during space flights. If so, the ex vivo system described above can be used to understand cellular and molecular mechanisms of this dysfunction.
authors.affiliation: NASA/NIH Center for Three-Dimensional Tissue Culture, Laboratory of Cellular and Molecular Biophysics, Program in Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Wendy
authors.initials: W
authors.lastname: Fitzgerald
authors.forename: Silvia
authors.initials: S
authors.lastname: Chen
authors.forename: Carl
authors.initials: C
authors.lastname: Walz
authors.forename: Joshua
authors.initials: J
authors.lastname: Zimmerberg
authors.forename: Leonid
authors.initials: L
authors.lastname: Margolis
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Grivel
mesh_terms: D000917:Antibody Formation / Q000502:physiology; D018929:Cell Culture Techniques; D005118:Extraterrestrial Environment; D006801:Humans; D056724:Immunity, Humoral / Q000502:physiology*; D007165:Immunosuppression Therapy; D008214:Lymphocytes / Q000276:immunology*; D014481:United States; D018557:United States National Aeronautics and Space Administration; D018474:Weightlessness Simulation