title: Number and function of circulating human antigen presenting cells regulated by sleep.
abstract: OBJECTIVE
  There is evidence that sleep facilitates the adaptive immune response to infectious agents and, thereby, supports immunologic memory. The effect might be attained by sleep-induced changes in the number and function of dendritic cells (DCs), which play a key role in the initiation of the immune response. This study aimed to dissociate effects of sleep and circadian rhythm on circulating numbers of DC precursors, ie, CD14+CD16- and CD14(dim)CD16+ monocytes, myeloid dendritic cell precursors (pre-mDC), and plasmacytoid dendritic cells (PDC) and on 2 key cytokines produced by these cells, ie, interleukin (IL)-12 and interferon (IFN)-alpha.
  
  
  METHODS
  In a within-subject cross-over design, human subjects were examined on 2 occasions, ie, during a normal sleep-wake cycle and during 24 hours of wakefulness. Blood was sampled every 1.5 hours during nighttime and every 3 hours during daytime.
  
  
  METHODS
  Experiments took place under controlled laboratory conditions.
  
  
  METHODS
  Twenty-seven healthy men aged between 18 and 30 years.
  
  
  RESULTS
  Compared with wakefulness, sleep was associated with a striking increase in the number of pre-mDC producing IL-12, which is a main inducer of Th1 responses. In addition, sleep slightly decreased PDC and also T cell counts but did not affect IFN-alpha production by PDC. Sleep, however, substantially decreased numbers of CD14(dim)CD16+ monocytes, probably reflecting increased margination of the cells upon a sleep-related drop in catecholamine release.
  
  
  CONCLUSIONS
  Our data identify pre-mDC producing IL-12 as a basic target of sleep that is most closely related to mature APC function and whereby sleep can effectively enhance adaptive immune responses.
authors.affiliation: Department of Neuroendocrinology, University of Lübeck, Germany.
authors.forename: Stoyan
authors.initials: S
authors.lastname: Dimitrov
authors.forename: Tanja
authors.initials: T
authors.lastname: Lange
authors.forename: Klaus
authors.initials: K
authors.lastname: Nohroudi
authors.forename: Jan
authors.initials: J
authors.lastname: Born
mesh_terms: D000293:Adolescent; D000328:Adult; D000938:Antigen-Presenting Cells / Q000276:immunology*; D002940:Circadian Rhythm / Q000276:immunology; D006801:Humans; D007110:Immunity, Active / Q000276:immunology; D007156:Immunologic Memory; D016898:Interferon-alpha / Q000097:blood; D018664:Interleukin-12 / Q000097:blood; D007694:Killer Cells, Natural / Q000276:immunology; D007958:Leukocyte Count; D008297:Male; D009000:Monocytes / Q000276:immunology*; D012016:Reference Values; D012890:Sleep / Q000276:immunology*; D012892:Sleep Deprivation / Q000276:immunology; D014851:Wakefulness / Q000502:physiology
chemical_list: D016898:Interferon-alpha; D018664:Interleukin-12