Inflammatory cytokine production in interferon-gamma-primed mice, challenged with lipopolysaccharide. Inhibition by SK&F 86002 and interleukin-1 beta-converting enzyme inhibitor.
Mice challenged with lipopolysaccharide (LPS) produce variable serum levels of pro-inflammatory cytokines, and particularly low levels of interleukin-1 beta (IL-1 beta). Interferon-gamma (IFN-gamma) has been shown to be an important mediator of bacteria-induced hypersensitivity to LPS in mice. In the present study, we show that mice pretreated with IFN-gamma exhibit an enhanced capacity to produce serum IL-1 beta, IL-1 alpha, tumour necrosis factor (TNF-alpha) as well as IL-6 in response to LPS. Priming with intraperitoneal (i.p.) injection of 15 mg rat recombinant IFN-gamma, 18 hours prior to the i.p. LPS (300 mg) challenge resulted in a 4-fold increase in the LPS-stimulated release of IL-1 beta and a 2- to 7-fold increase in the release of IL-1 alpha, TNF-alpha, as well as IL-6 into the serum. LPS induced a concentration-dependent increase in the release of IL-1 beta in isolated peritoneal macrophages from IFN-gamma-primed mice whereas macrophages from unprimed mice released minute amounts of IL-1 beta. In addition, nigericin markedly enhanced the release of IL-1 beta in unprimed mice but not in macrophages from IFN-gamma primed mice. The cytokine synthesis inhibitor SK&F 86002, administered per os (100 mg/kg), 1 hour prior to LPS challenge, strongly inhibited the rise in serum levels of the four cytokines. Furthermore, treatment with the IL-1 beta converting enzyme (ICE) specific reversible inhibitor YVAD-CHO resulted in a sharp dose- and time-dependent inhibition of IL-1 beta secretion in the serum, whereas the other cytokines were not affected. In conclusion, IFN-gamma priming strongly potentiates the release of proinflammatory cytokines in the serum of mice as compared to LPS stimulation alone, and provides therefore a useful way to test the in vivo potency and selectivity of cytokine synthesis inhibitors.
Spinelle-Jaegle
S
S
Immunology Research Department, Hoechst Marion Roussel, Romainville, France.
Devillier
P
P
Doucet
S
S
Millet
S
S
Banissi
C
C
Diu-Hercend
A
A
Ruuth
E
E
D000818:Animals; D061945:Caspase Inhibitors; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D018836:Inflammation Mediators; D007371:Interferon-gamma / Q000008:administration & dosage*; D007378:Interleukins / Q000096:biosynthesis* / Q000097:blood; D017737:Macrophages, Peritoneal / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009842:Oligopeptides / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000378:metabolism
D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D018836:Inflammation Mediators; D007378:Interleukins; D009842:Oligopeptides; D014409:Tumor Necrosis Factor-alpha; C118632:tyrosyl-valyl-alanyl-aspartal; D007371:Interferon-gamma