A relationship between cannabinoids and T-helper cell biasing has been established by several lines of evidence (Klein experiments showed that THC injection suppressed the development of Th1 cell-mediated immunity to contamination, with decreased IFN-and IL-12 levels in the serum (Klein in a 12-h darkClight cycle. Cells were centrifuged at 800?r.p.m., 10?min at room heat (RT) and resuspended in Gey’s red cells lysis Resminostat buffer. After 20?min of incubation at RT, cells were centrifuged and resuspended in fresh Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% inactivated fetal bovine serum (FBS, Gibco BRL, Life Tech. Ltd, Germany), 100?U?ml?1 penicillin and 100?exposure, JWH-133 (10?nM, 100?nM, 1?M and 5?M) and the CB1 and CB2 receptor antagonists SR141716A and SR144528, respectively, were added at a dose of 1 1?M. LPS and IFN-were diluted in DMEM, and added to each well at a final concentration of 50?ng?ml?1 and 100?U?ml?1, respectively. JWH-133 stock solution was prepared in DMSO and aliquots (1?mM) were diluted in PBS and 1% DMSO. Control cells were cultured with the relevant amounts of DMSO. Cells stimulated were incubated 18?h at 37C in a humidified atmosphere with 5% CO2. After this time, cells were harvested for protein measurement, and supernatants collected for cytokine determination. Trypan blue dye exclusion screening or the 3,4,5-dimethylthiazol 2-5-diphenyltetrazolium bromide thiazol blue test indicated that this cannabinoid-related compounds at the highest concentrations used (5?(Serotype 026:B6, Sigma, Spain), Resminostat IFN-was from PeproTech (London U.K.). JWH-133 was purchased from Tocris Cookson Ltd (U.K.). SR141716A (stimulated macrophages. To evaluate this, we measured IL-12p40 levels in the supernatants of LPS/IFN-stimulated macrophage cultures in the presence or absence of the selective CB2 agonist JWH-133. Cells were preincubated with different doses of JWH-133 or vehicle for 5?min, before activation with LPS/IFN-for 18?h, and tested for IL-12p40 levels in cell supernatants. JWH-133 inhibited LPS/IFN-induced IL-12 production in a dose-dependent manner (Physique 1a), but the higher dose used (5?(100?U?ml?1) activation for 18?h following which cell supernatants were harvested and analyzed for IL-12p40 production. The results shown are the means.e.m. of three impartial experiments in triplicate. Statistics: *(100?U?ml?1) activation for 18?h, following which supernatants were collected and analyzed for IL-12p40 production. The results shown are the means.e.m. of three impartial experiments performed in Resminostat triplicate. Statistics: *plus JWH-133. ERK1/2 activation is usually associated with JWH-133-mediated IL-12p40 inhibition by LPS-activated macrophages The molecular mechanisms underlying regulation of IL-12 production in macrophages are not fully understood. It has been suggested that MAPKs regulate IL-12 production in APC cells (Feng (100?U?ml?1) activation for 18?h, following which cell supernatants were harvested and analyzed for IL-10 production. The results shown are the means.e.m. of three impartial experiments perfomred in triplicate. Statistics: *contamination, but this effect appeared to involve both type of receptors, CB1 and CB2 receptors (Klein experiments have shown that other CB agonists, WIN 55212-2 and HU-210, decreased IL-12 and increased levels of IL-10 in the serum of LPS-treated mice through a CB1 receptor action (Smith and TNF-following activation with LPS/IFN-(Klegeris em et al /em ., 2003) and a decrease of neurotoxicity of culture supernatants. In addition, activation of CB2 receptors also decreases the expression of MHC class II antigens by activated macrophages (unpublished results). The overall actions due to activation of CB2 receptors in cells of macrophage lineage may prevent the generation of a Th-1 immune response affecting the required immunity to combact a particular pathogen or, alternatively, reduce inflammation/pathology associated with certain chronic disease says, such as MS. In summary, the results of this study show that (i) activation of CB2 receptors inhibits IL-12p40 production and enhances IL-10 biosynthesis by activated macrophages, (ii) JWH-133 may exert its inhibitory effect on IL-12p40 production by a greater and sustained activation of ERK1/2 MAP kinase, (iii) pharmacological inhibition of ERK promotes IL-12p40 production and reduces IL-10 by activated macrophages, (iv) increased endogenous IL-10 secretion may also contribute to this inhibition by acting in an autocrine way. These results suggest that CB2 agonists might be useful for chronic inflammatory diseases therapies. Additional research is being performed to establish the possible role of endocannabinoids in the regulation of immunity in normal and pathological conditions. Acknowledgments We gratefully appreciate Dr M. Rodriguez (Department of Immunology and Neurology, Mayo Medical center/Foundation, Rochester, MN, U.S.A.) for kindly providing Theiler’s virus strain. This work was supported by grants from your MCYT Rabbit Polyclonal to ATG4D (SAF-2001/1246 and SAF 2004-00416). Abbreviations APCsantigen presenting cellsCBscannabinoidsCB1 receptortype I CB receptorCB2 receptortype 2 CB receptorDTHdelayed-type hypersensivityERKextracellular signal-regulated kinaseFBSfetal bovine serumIFN- em /em interferon-gammaIL-10interleukin-10IL-12interleukin-12LPSlipopolyssacharideMAP kinasemitogen-activated protein kinaseMHCmajor histocompatibility complexMSmultiple sclerosisMOImultiplicity of infectionTHCtetrahydrocannabinolTh1T helper 1Th2T helper 2TMEVTheiler’s virusTMEV-IDDTheiler’s computer virus induced demyelinating disease.