title: TH1-biased immunity induced by exposure to Antarctic winter.
abstract: BACKGROUND
  Certain immune functions are known to be impaired in human beings exposed to Antarctic winter; in particular, decreased amounts of serum proinflammatory cytokines, such as TNF-alpha and IL-1, were noted. It is not known, however, whether this exposure has any effect on T-cell-mediated acquired immune functions.
  
  
  OBJECTIVE
  This study aims to investigate whether exposure to Antarctic winter has any effect on T cell-dependent immune functions.
  
  
  METHODS
  We assessed changes in various immunologic indicators, including serum levels of various cytokines, peripheral blood Valpha24Vbeta11 natural killer T cell numbers, and T(H)1/T(H)2 ratios of 40 Japanese personnel exposed to an Antarctic winter. Also, a 2-month inland traverse was executed during the isolation, and the effect on the above indicators was assessed.
  
  
  RESULTS
  All subjects were healthy during the Antarctic isolation. The levels of serum TNF-alpha, IL-1Ra, IL-6, and IL-1beta were dramatically reduced and remained at low levels throughout the isolation. The decrease in the levels of TNF-alpha and IL-1Ra was more pronounced during the inland traverse than during the rest of the isolation. The percentage of Valpha24Vbeta11 natural killer T cells was significantly increased at the midpoint of the isolation. Most interestingly, T(H)1/T(H)2 ratio was increased significantly, and this T(H)1 bias was most prominent at the late point of the isolation.
  
  
  CONCLUSIONS
  Exposure to an Antarctic winter appeared to induce T(H)1-skewed immunity in human beings.
authors.affiliation: Department of Molecular Immunology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors.forename: Takushi
authors.initials: T
authors.lastname: Shirai
authors.forename: Kumiko K
authors.initials: KK
authors.lastname: Magara
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Motohashi
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Yamashita
authors.forename: Motoko
authors.initials: M
authors.lastname: Kimura
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Suwazomo
authors.forename: Koji
authors.initials: K
authors.lastname: Nogawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kuriyama
authors.forename: Masaru
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Toshinori
authors.initials: T
authors.lastname: Nakayama
mesh_terms: D000328:Adult; D000864:Antarctic Regions; D003080:Cold Temperature; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D006403:Hematologic Tests; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007135:Immunoglobulin Variable Region / Q000032:analysis; D007694:Killer Cells, Natural / Q000276:immunology; D008297:Male; D008875:Middle Aged; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000737:chemistry; D012621:Seasons; D016176:T-Lymphocyte Subsets / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology
chemical_list: D016207:Cytokines; D007135:Immunoglobulin Variable Region; D016693:Receptors, Antigen, T-Cell, alpha-beta; D007073:Immunoglobulin E