Role of interleukin-1beta and tumour necrosis factor-alpha in lipopolysaccharide-induced sickness behaviour: a study with interleukin-1 type I receptor-deficient mice.
Interleukin-1 (IL-1) mediates symptoms of sickness during the host response to infection. IL-1 exerts its effects via several subtypes of receptors. To assess the role of IL-1 receptor type I (IL-1RI) in the sickness-inducing effects of IL-1, IL-1beta and the cytokine inducer lipopolysaccharide were administered to IL-1RI-deficient mice (IL-1RI-/-). Sickness was assessed by depression of social exploration, anorexia, immobility and body weight loss. IL-1RI-/- mice were resistant to the sickness-inducing effects of IL-1beta administered intraperitoneally (2 microg/mouse) and intracerebroventricularly (2 ng/mouse), but still fully responsive to lipopolysaccharide administered intraperitoneally (2.5 microg/mouse) and intracerebroventricularly (3 ng/mouse). The sensitivity of IL-1RI-/- mice to lipopolysaccharide was not due to a higher brain expression of proinflammatory cytokines other than IL-1, since lipopolysaccharide-induced expression of brain IL-1 beta, tumour necrosis factor-alpha (TNF-alpha) and IL-6 transcripts were identical in IL-1RI-/- and control mice when measured by semiquantitative reverse-transcriptase polymerase chain reaction 1 h after treatment. Blockade of TNF-alpha action in the brain by intracerebroventricular administration of a fragment of the soluble TNF receptor, TNF binding protein (3.6 microg/mouse), attenuated the depressive effects of intraperitoneal injection of lipopolysaccharide (1 microg/mouse) on behaviour in IL-1RI-/- but not in control mice. Since IL-1RI-/- mice were not more sensitive to intracerebroventricularly TNF-alpha (50 ng) than control mice, these results indicate that IL-1RI mediates the sickness effect of IL-1 and that TNF-alpha simply replaces IL-1 when this last cytokine is deficient.
Bluthé
R M
RM
INRA-INSERM U394, Institut François Magendie, 1 rue Camille Saint-Saëns, 33077 Bordeaux cedex, France; Université Bordeaux I, 33400 Talence, France.
Layé
S
S
Michaud
B
B
Combe
C
C
Dantzer
R
R
Parnet
P
P
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D005106:Exploratory Behavior; D005786:Gene Expression Regulation / Q000187:drug effects; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D007375:Interleukin-1 / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D015850:Interleukin-6 / Q000235:genetics / Q000502:physiology; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D017472:Receptors, Interleukin-1 / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D053573:Receptors, Interleukin-1 Type I; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012919:Social Behavior; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000502:physiology*
D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D017472:Receptors, Interleukin-1; D053573:Receptors, Interleukin-1 Type I; D014409:Tumor Necrosis Factor-alpha