Inducible expression of functional mu opioid receptors in murine dendritic cells.
Opioids are known to exert direct effects on the immune system, and the expression of functional opioid receptors has been reported on several immune cell types. Dendritic cells (DCs) are important inducers and regulators of immune responses. In this study, we investigated whether murine dendritic cells express functional mu opioid receptors (MOR). RT-PCR analysis and double immunofluorescence staining revealed the expression of MOR in activated murine dendritic cells. We also studied the dynamic expression of MOR messenger RNA in murine dendritic cells in response to different Toll-like receptor ligands. Functionally, treatment of DCs with endomorphin 1 (EM1), a specific agonist of MOR, can inhibit the forskolin-induced formation of cyclic adenosine monophosphate level in activated DCs. Moreover, EM1 treatment resulted in less activation of p38 MAPK and more activation of ERK signaling in lipopolysaccharide-stimulated DCs. Consistently, treatment of DCs with EM1 altered cytokine production by increasing IL-10 and decreasing IL-12 and IL-23. Our results suggest that MOR is inducibly expressed on activated DCs and functionally mediates EM1-induced effects on DCs. Thus, dendritic cells might be involved in crosstalk between the neuroendocrine and the immune system.
Li
Zheng-Hong
ZH
Department of Neurobiology, School of Medicine, Soochow University, Suzhou 215123, People's Republic of China.
Chu
Niansheng
N
Shan
Li-Dong
LD
Gong
Shan
S
Yin
Qi-Zhang
QZ
Jiang
Xing-Hong
XH
D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000187:drug effects / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis; D003713:Dendritic Cells / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D016753:Interleukin-10 / Q000096:biosynthesis; D018664:Interleukin-12 / Q000096:biosynthesis; D053759:Interleukin-23 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D009842:Oligopeptides / Q000494:pharmacology; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D000701:Analgesics, Opioid; D053759:Interleukin-23; D008070:Lipopolysaccharides; D009842:Oligopeptides; D017450:Receptors, Opioid, mu; C105293:endomorphin 1; D016753:Interleukin-10; D018664:Interleukin-12; D005576:Colforsin; D000242:Cyclic AMP; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases