title: Primary Macrophage Chemotaxis Induced by Cannabinoid Receptor 2 Agonists Occurs Independently of the CB2 Receptor.
abstract: Activation of CB2 has been demonstrated to induce directed immune cell migration. However, the ability of CB2 to act as a chemoattractant receptor in macrophages remains largely unexplored. Using a real-time chemotaxis assay and a panel of chemically diverse and widely used CB2 agonists, we set out to examine whether CB2 modulates primary murine macrophage chemotaxis. We report that of 12 agonists tested, only JWH133, HU308, L-759,656 and L-759,633 acted as macrophage chemoattractants. Surprisingly, neither pharmacological inhibition nor genetic ablation of CB2 had any effect on CB2 agonist-induced macrophage chemotaxis. As chemotaxis was pertussis toxin sensitive in both WT and CB2(-/-) macrophages, we concluded that a non-CB1/CB2, Gi/o-coupled GPCR must be responsible for CB2 agonist-induced macrophage migration. The obvious candidate receptors GPR18 and GPR55 could not mediate JWH133 or HU308-induced cytoskeletal rearrangement or JWH133-induced β-arrestin recruitment in cells transfected with either receptor, demonstrating that neither are the unidentified GPCR. Taken together our results conclusively demonstrate that CB2 is not a chemoattractant receptor for murine macrophages. Furthermore we show for the first time that JWH133, HU308, L-759,656 and L-759,633 have off-target effects of functional consequence in primary cells and we believe that our findings have wide ranging implications for the entire cannabinoid field.
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
authors.forename: Lewis
authors.initials: L
authors.lastname: Taylor
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
authors.forename: Ivy
authors.initials: I
authors.lastname: Christou
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
authors.forename: Theodore S
authors.initials: TS
authors.lastname: Kapellos
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
authors.forename: Alice
authors.initials: A
authors.lastname: Buchan
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
authors.forename: Maximillian H
authors.initials: MH
authors.lastname: Brodermann
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
authors.forename: Matteo
authors.initials: M
authors.lastname: Gianella-Borradori
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
authors.forename: Angela
authors.initials: A
authors.lastname: Russell
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
authors.forename: Asif J
authors.initials: AJ
authors.lastname: Iqbal
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
authors.forename: David R
authors.initials: DR
authors.lastname: Greaves
mesh_terms: D000818:Animals; D016466:CHO Cells; D002186:Cannabinoids / Q000494:pharmacology; D002460:Cell Line; D002630:Chemotactic Factors / Q000494:pharmacology*; D002634:Chemotaxis, Leukocyte / Q000187:drug effects* / Q000502:physiology*; D003412:Cricetulus; D005260:Female; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists / Q000378:metabolism; D043885:Receptor, Cannabinoid, CB2 / Q000819:agonists* / Q000235:genetics / Q000378:metabolism*; D043882:Receptors, Cannabinoid; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism
chemical_list: D002186:Cannabinoids; D002630:Chemotactic Factors; C107515:GPR18 protein, human; C524885:GPR55 protein, human; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D043882:Receptors, Cannabinoid; D043562:Receptors, G-Protein-Coupled; C402416:HU 308