title: Effects of spaceflight on innate immune function and antioxidant gene expression.
abstract: Spaceflight conditions have a significant impact on a number of physiological functions due to psychological stress, radiation, and reduced gravity. To explore the effect of the flight environment on immunity, C57BL/6NTac mice were flown on a 13-day space shuttle mission (STS-118). In response to flight, animals had a reduction in liver, spleen, and thymus masses compared with ground (GRD) controls (P < 0.005). Splenic lymphocyte, monocyte/macrophage, and granulocyte counts were significantly reduced in the flight (FLT) mice (P < 0.05). Although spontaneous blastogenesis of splenocytes in FLT mice was increased, response to lipopolysaccharide (LPS), a B-cell mitogen derived from Escherichia coli, was decreased compared with GRD mice (P < 0.05). Secretion of IL-6 and IL-10, but not TNF-alpha, by LPS-stimulated splenocytes was increased in FLT mice (P < 0.05). Finally, many of the genes responsible for scavenging reactive oxygen species were upregulated after flight. These data indicate that exposure to the spaceflight environment can increase anti-inflammatory mechanisms and change the ex vivo response to LPS, a bacterial product associated with septic shock and a prominent Th1 response.
authors.affiliation: Department of Radiation Medicine, Loma Linda University, Loma Linda, CA 92354, USA. fpirayesh05b@llu.edu
authors.forename: Farnaz P
authors.initials: FP
authors.lastname: Baqai
authors.forename: Daila S
authors.initials: DS
authors.lastname: Gridley
authors.forename: James M
authors.initials: JM
authors.lastname: Slater
authors.forename: Xian
authors.initials: X
authors.lastname: Luo-Owen
authors.forename: Louis S
authors.initials: LS
authors.lastname: Stodieck
authors.forename: Virginia
authors.initials: V
authors.lastname: Ferguson
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Chapes
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pecaut