Immune responses in adult female volunteers during the bed-rest model of spaceflight: Antibodies and cytokines

• Published in: Journal of allergy and clinical immunology Vol. 123; no. 4; pp. 900 - 905
• Main Authors: Shearer, William T., MD, PhD, Ochs, Hans D., MD, Lee, Bang-Ning, PhD, Cohen, Evan N., BS, Reuben, James M., PhD, Cheng, Irene, MS, Thompson, Bruce, PhD, Butel, Janet S., PhD, Blancher, Antoine, MD, Abbal, Michel, MD, Aviles, Hernan, MD, PhD, Sonnenfeld, Gerald, PhD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-04-2009; Elsevier; Elsevier Limited
• Subjects: Adult; Allergy and Immunology; Antibody Formation; Bacteriophage phi X 174 - immunology; Bed Rest; Biological and medical sciences; Chemokine CCL5 - blood; Cytokines; Cytokines - blood; Drug dosages; Exercise; Experiments; Female; female study subjects; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Head-down tilt; Human subjects; Humans; IgG class switching; Immunization; Immunopathology; Interleukin 1 Receptor Antagonist Protein - blood; Medical research; Medical sciences; Physical fitness; Plasma; proinflammatory and anti-inflammatory cytokines; Proteins; Receptors, Tumor Necrosis Factor, Type I - blood; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Space Flight; spaceflight model; Studies; φX-174 immunization; IL-1RA; IL-1 receptor antagonist; φX-174; GEE; K value; Bacteriophage φX-174; General estimating equations; Kv; HDBR; Head-down bed rest; φX-174 immunization; Soluble TNF receptor 1; bed rest; IgG class switching; sTNFR1; Head-down tilt; proinflammatory and anti-inflammatory cytokines; spaceflight model; female study subjects; Vaccination; Volunteer; IgG; Rest; Immunology; Isotype switch; Adult; Female; Human; Bed; Immunopathology; Immunization; Immunoglobulins; Head; Immune response; Antibody; Antiinflammatory agent; Cytokine; pX-174 immunization; Inflammation; Models
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2008.12.016

Background It is unknown whether a prolonged period of bed rest will affect human immune responses, particularly in female subjects. Objective We sought to measure immune responses in adult female subjects exposed to prolonged bed rest. Methods Adult (25-40 years) female volunteers (n = 24) were maintained in a supine (6° tilt) head-down bed-rest (HDBR) position for 60 days: 8 with HDBR only, 8 with HDBR and regular muscular exercise, and 8 with HDBR and dietary protein supplementation. Subjects were immunized with bacteriophage φX-174. Antibody production and plasma cytokine levels were determined. Results The rate of primary antibody production of the HDBR plus exercise group increased faster ( P = .01) and to a higher level versus that of the HDBR-only group ( P = .03) and that of the HDBR plus diet group (trend P = .08). The rates of secondary antibody production between the 3 groups were similar, but the level of antibody in the HDBR plus exercise group remained higher versus that in the HDBR-only group ( P = .03). Both the HDBR ( P = .001) and HDBR plus diet ( P = .02) groups had time-related progressive increases in TNF-α receptor levels, but the HDBR plus exercise group remained at baseline. The HDBR plus exercise group experienced an acute increase in IL-1 receptor antagonist levels versus the HDBR ( P = .02) and the HDBR plus diet ( P = .02) groups, with similar increases in RANTES levels. Conclusions The exercise countermeasure accelerated primary antibody production and increased antibody levels to bacteriophage φX-174 and also opposed the potentially harmful effects of increased TNF-α levels caused by prolonged bed rest, possibly by activating the anti-inflammatory cytokine IL-1 receptor antagonist and the chemotactic factor RANTES.