title: Functional expression of adenosine A2A and A3 receptors in the mouse dendritic cell line XS-106.
abstract: There is increasing evidence to suggest that adenosine receptors can modulate the function of cells involved in the immune system. For example, human dendritic cells derived from blood monocytes have recently been described to express functional adenosine A1, A2A and A3 receptors. Therefore, in the present study, we have investigated whether the recently established murine dendritic cell line XS-106 expresses functional adenosine receptors. The selective adenosine A3 receptor agonist 1-[2-chloro-6[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-1-deoxy-N-methyl-beta-D-ribofuranuronamide (2-Cl-IB-MECA) inhibited forskolin-mediated [3H]cyclic AMP accumulation and stimulated concentration-dependent increases in p42/p44 mitogen-activated protein kinase (MAPK) phosphorylation. The selective adenosine A2A receptor agonist 4-[2-[[-6-amino-9-(N-ethyl-beta-D-ribofuranuronamidosyl)-9H-purin-2-yl]amino]ethyl]benzene-propanoic acid (CGS 21680) stimulated a robust increase in [3H]cyclic AMP accumulation and p42/p44 MAPK phosphorylation. In contrast, the selective adenosine A1 receptor agonist CPA (N6-cyclopentyladenosine) did not inhibit forskolin-mediated [3H]cyclic AMP accumulation or stimulate increases in p42/p44 MAPK phosphorylation. These observations suggest that XS-106 cells express functional adenosine A2A and A3 receptors. The non-selective adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA) inhibited lipopolysaccharide-induced tumour necrosis factor-alpha (TNF-alpha) release from XS-106 cells in a concentration-dependent fashion. Furthermore, treatment with Cl-IB-MECA (1 microM) or CGS 21680 (1 microM) alone produced a partial inhibition of lipopolysaccharide-induced TNF-alpha release (when compared to NECA), whereas a combination of both agonists resulted in the inhibition of TNF-alpha release comparable to that observed with NECA alone. Treatment of cells with the adenosine A2A receptor selective antagonists 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5ylamino]ethyl)phenol (ZM 241385; 100 nM) and 5-amino-2-(2-furyl)-7-phenylethyl-pyrazolo[4,3-e]-1,2,4-triazolo[1,5c]pyrimidine (SCH 58261; 100 nM) and the adenosine A3 receptor selective antagonist N-[9-chloro-2-(2-furanyl)[1,2,4]-triazolo[1,5-c]quinazolin-5-benzeneacetamide (MRS 1220; 100 nM) partially blocked the inhibitory effects of NECA on lipopolysaccharide-induced TNF-alpha release. Combined addition of MRS 1220 and SCH 58261 completely blocked the inhibitory effects of NECA on lipopolysaccharide-induced TNF-alpha release. In conclusion, we have shown that the mouse dendritic cell line XS-106 expresses functional adenosine A2A and A3 receptors, which are capable of modulating TNF-alpha release.
authors.affiliation: Department of Life Sciences, Faculty of Science and Mathematics, School of Science, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK. john.dickenson@ntu.ac.uk
authors.forename: John M
authors.initials: JM
authors.lastname: Dickenson
authors.forename: Steve
authors.initials: S
authors.lastname: Reeder
authors.forename: Bob
authors.initials: B
authors.lastname: Rees
authors.forename: Steve
authors.initials: S
authors.lastname: Alexander
authors.forename: Dave
authors.initials: D
authors.lastname: Kendall
mesh_terms: D058908:Adenosine A2 Receptor Agonists; D058909:Adenosine A3 Receptor Agonists; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D000242:Cyclic AMP / Q000037:antagonists & inhibitors; D003713:Dendritic Cells / Q000378:metabolism*; D004789:Enzyme Activation; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010766:Phosphorylation; D043705:Receptor, Adenosine A2A / Q000096:biosynthesis*; D043684:Receptor, Adenosine A3 / Q000096:biosynthesis*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D058908:Adenosine A2 Receptor Agonists; D058909:Adenosine A3 Receptor Agonists; D043705:Receptor, Adenosine A2A; D043684:Receptor, Adenosine A3; D014409:Tumor Necrosis Factor-alpha; D000242:Cyclic AMP; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases