title: Dietary nucleotides prevent decrease in cellular immunity in ground-based microgravity analog.
abstract: Microgravity and stress of spaceflights result in immune dysfunction. The role of nutrition, especially nucleotide supplementation, has become an area of intensive research and significant interest in immunomodulation for maintenance of cellular immune responses. The studies presented here evaluate the plausibility of administering nucleotides to obviate immune dysfunction in an Earth-based in vivo analog of microgravity as studied in anti-orthostatic tail suspension (AOS) of mice. Mice were divided into three housing groups: group, isolation, and AOS. Mice were fed either control chow diet (CD), or RNA-, adenine-, or uracil-supplemented CD for the 1-wk duration of the experiments. In AOS mice, supplemental nucleotides significantly increased in vivo lymph node proliferation and ex vivo lymphoproliferation response to alloantigen and mitogens, respectively, and interleukin-2 and interferon-gamma production. A lower corticosterone level was observed in uracil-supplemented CD compared with CD. These results suggest that exogenous nucleotide supplementation, especially uracil, of normal diet is beneficial in the maintenance and restoration of the immune response during the microgravity analog conditions.
authors.affiliation: Department of Surgery, University of Texas Health Science Center Houston, Texas 77030, USA.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Nathan W
authors.initials: NW
authors.lastname: Hales
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Robinson
authors.forename: Michael L
authors.initials: ML
authors.lastname: Niehoff
authors.forename: Vani
authors.initials: V
authors.lastname: Ramesh
authors.forename: Neal R
authors.initials: NR
authors.lastname: Pellis
authors.forename: Anil D
authors.initials: AD
authors.lastname: Kulkarni
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003345:Corticosterone / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D004032:Diet; D005260:Female; D019417:Hindlimb Suspension / Q000502:physiology*; D007111:Immunity, Cellular / Q000187:drug effects*; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009841:Oligonucleotides / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D013154:Spleen / Q000166:cytology / Q000187:drug effects
chemical_list: D016207:Cytokines; D009841:Oligonucleotides; D003345:Corticosterone