Effects of sleep and circadian rhythm on the human immune system.
Many immune parameters show systematic fluctuations over the 24-h day in human blood. Circulating naive T-cells and production of proinflammatory cytokines, like interleukin-12 (IL-12), peak during nighttime, whereas cytotoxic effector leukocytes and production of the anti-inflammatory cytokine IL-10 peak during daytime. These temporal changes originate from a combined influence of the circadian system and sleep. Both brain functions act synergistically and share neuroendocrine effector mechanisms to convey control over immune functions. Sympathetic tone and cortisol levels show a circadian nadir during nighttime and are further suppressed by sleep, whereas growth hormone and prolactin show a circadian peak during nighttime and are further enhanced by sleep. Thus, the circadian system and sleep jointly evoke a unique endocrine constellation that is extremely effective in inducing changes in leukocyte traffic and a shift toward proinflammatory type 1-cytokines during the nocturnal period of sleep, that is, an action with strong clinical implications.
Lange
Tanja
T
Department of Neuroendocrinology, University of Lübeck, Lübeck, Germany. lange@kfg.uni-luebeck.de
Dimitrov
Stoyan
S
Born
Jan
J
D002940:Circadian Rhythm; D013006:Growth Hormone / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000502:physiology; D007107:Immune System / Q000502:physiology*; D016753:Interleukin-10 / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D008297:Male; D011388:Prolactin / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology
D016753:Interleukin-10; D018664:Interleukin-12; D011388:Prolactin; D013006:Growth Hormone; D006854:Hydrocortisone