title: Acute stressor exposure both suppresses acquired immunity and potentiates innate immunity.
abstract: Acute stressor exposure alters immune function. Rats exposed to inescapable tail shock stress (IS) generate less antibody to a benign, antigenic protein, keyhole limpet hemocyanin (KLH). The following studies examined the effect of IS on peritoneal cavity, spleen, and mesenteric lymph node cell number, interferon-gamma (IFN-gamma) production, and nitrite production. Rats were injected intraperitoneally with KLH (200 microg) or saline immediately before IS exposure and killed 0, 48, and 96 h after IS termination. KLH immunization resulted in elevated cell numbers and IFN-gamma levels 2-4 days later in nonstressed control rats. In contrast, rats exposed to IS failed to increase cell number and IFN-gamma levels in response to KLH. The T cell subpopulations affected were CD4 T cells, specifically the Th1-like subset. In addition, in rats exposed to IS + KLH, nitrite production was potentiated 2-4 days after stressor termination. IS had little effect on these measures in saline-injected rats. These data support the conclusion that exposure to IS suppresses the expansion of anti-KLH lymphocytes, possibly anti-KLH Th1 cells. In addition, stressor exposure potentiates the production of nitrite. Importantly, this potentiated response occurred only in KLH-immunized animals, suggesting that macrophages may be primed by stressor exposure and thus respond more vigorously to antigen. The potential links between these changes are discussed.
authors.affiliation: Department of Kinesiology and Applied Physiology, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: M
authors.initials: M
authors.lastname: Fleshner
authors.forename: K T
authors.initials: KT
authors.lastname: Nguyen
authors.forename: C S
authors.initials: CS
authors.lastname: Cotter
authors.forename: L R
authors.initials: LR
authors.lastname: Watkins
authors.forename: S F
authors.initials: SF
authors.lastname: Maier
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000941:Antigens / Q000276:immunology; D018791:CD4 Lymphocyte Count; D002452:Cell Count; D004597:Electroshock; D006433:Hemocyanins / Q000276:immunology; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000096:biosynthesis; D008198:Lymph Nodes / Q000166:cytology; D008297:Male; D008643:Mesentery; D009573:Nitrites / Q000378:metabolism; D010529:Peritoneal Cavity / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000166:cytology; D013312:Stress, Physiological / Q000276:immunology*; D013623:Tail
chemical_list: D000941:Antigens; D009573:Nitrites; D007371:Interferon-gamma; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin