Distinct regulation by lipopolysaccharides of the expression of interleukin-1β by murine macrophages and salivary glands.
The regulation of interleukin (IL)-1 expression and secretion by salivary glands and macrophages in response to lipopolysaccharides (LPS) was compared. In wild-type mice, injection of LPS significantly decreased the volume of saliva stimulated by pilocarpine and increased its protein and amylase concentration. It did not modify the salivary concentration of IL-1β. The cytokine was expressed by submandibular acini and ducts. Macrophages also expressed IL-1β but at lower concentration than salivary glands. The pre-incubation of macrophages with LPS increased the phosphorylation of IκB and the expression of IL-1β. Adenosine triphosphate also promoted the secretion of the cytokine by these cells. These responses were absent in submandibular gland cells. These glands expressed CD14, TLR4 and MyD88. P2X(7)-KO mice secreted a lower volume of saliva which contained less proteins and amylase. In conclusion, IL-1β is constitutively expressed by submandibular glands and its secretion is not regulated by a P2X(7) agonist. In these cells, LPS do not activate the nuclear factor-κB-pro-IL-1β axis in spite of the expression of the proteins involved in their recognition.
Seil
M
M
Laboratoire de Chimie biologique et médicale et de Microbiologie pharmaceutique, Institut de Pharmacie, Université libre de Bruxelles, Brussels, Belgium.
El Ouaaliti
M
M
Abdou Foumekoye
S
S
Pochet
S
S
Dehaye
J P
JP
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects; D051550:I-kappa B Kinase / Q000378:metabolism; D053583:Interleukin-1beta / Q000235:genetics / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010766:Phosphorylation / Q000187:drug effects; D010862:Pilocarpine / Q000008:administration & dosage; D058486:Receptors, Purinergic P2X7 / Q000235:genetics; D012463:Saliva / Q000378:metabolism*; D012469:Salivary Glands / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000276:immunology
D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D058486:Receptors, Purinergic P2X7; D010862:Pilocarpine; D000255:Adenosine Triphosphate; D051550:I-kappa B Kinase