Cannabinoid receptor type 1- and 2-mediated increase in cyclic AMP inhibits T cell receptor-triggered signaling.
The aim of this study was to characterize inhibitory mechanisms on T cell receptor signaling mediated by the cannabinoid receptors CB1 and CB2. Both receptors are coupled to G(i/o) proteins, which are associated with inhibition of cyclic AMP formation. In human primary and Jurkat T lymphocytes, activation of CB1 by R(+)-methanandamide, CB2 by JWH015, and both by Delta9-tetrahydrocannabinol induced a short decrease in cyclic AMP lasting less than 1 h. However, this decrease was followed by a massive (up to 10-fold) and sustained (at least up to 48 h) increase in cyclic AMP. Mediated by the cyclic AMP-activated protein kinase A and C-terminal Src kinase, the cannabinoids induced a stable phosphorylation of the inhibitory Tyr-505 of the leukocyte-specific protein tyrosine kinase (Lck). By thus arresting Lck in its inhibited form, the cannabinoids prevented the dephosphorylation of Lck at Tyr-505 in response to T cell receptor activation, which is necessary for the subsequent initiation of T cell receptor signaling. In this way the cannabinoids inhibited the T cell receptor-triggered signaling, i.e. the activation of the zeta-chain-associated protein kinase of 70 kDa, the linker for activation of T cells, MAPK, the induction of interleukin-2, and T cell proliferation. All of the effects of the cannabinoids were blocked by the CB1 and CB2 antagonists AM281 and AM630. These findings help to better understand the immunosuppressive effects of cannabinoids and explain the beneficial effects of these drugs in the treatment of T cell-mediated autoimmune disorders like multiple sclerosis.
Departments of Pharmacology and Toxicology, University of Magdeburg, 39120 Magdeburg, Germany.
Christine
C
Börner
Michal
M
Smida
Volker
V
Höllt
Burkhart
B
Schraven
Jürgen
J
Kraus
D001095:Arachidonic Acids / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000081247:CSK Tyrosine-Protein Kinase; D002186:Cannabinoids / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D000242:Cyclic AMP / Q000276:immunology / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases; D013759:Dronabinol / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects / Q000276:immunology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000276:immunology / Q000378:metabolism; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000276:immunology; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000276:immunology / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009103:Multiple Sclerosis / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects / Q000276:immunology; D011505:Protein-Tyrosine Kinases; D011619:Psychotropic Drugs / Q000032:analysis / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D043884:Receptor, Cannabinoid, CB1 / Q000276:immunology / Q000378:metabolism*; D043885:Receptor, Cannabinoid, CB2 / Q000276:immunology / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D019061:src-Family Kinases
D001095:Arachidonic Acids; D002186:Cannabinoids; C508594:IL2 protein, human; D007211:Indoles; D007376:Interleukin-2; D009025:Morpholines; D011619:Psychotropic Drugs; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D011948:Receptors, Antigen, T-Cell; C088155:methanandamide; D013759:Dronabinol; D000242:Cyclic AMP; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D019061:src-Family Kinases; C000631346:CSK protein, human; D017868:Cyclic AMP-Dependent Protein Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; C109925:AM 281; C094023:iodopravadoline