REGULATION OF MATURATION MARKERS AND PROINFLAMMATORY CYTOKINES BY MUSCARINIC ACTIVATION. PARTICIPATION OF NITRIC OXIDE

LOMBARDI MG; SALAMONE G; MARTINEZ P; GORI MS; YUSEFF ALVAREZ MF; GRAZIANO E; GEFFNER J; SALES ME

Simposio; 12th International Symposium on Dendritic Cells; 2012

The non-neuronal cholinergic system is constituted by acetylcholine (Ac), enzymes that synthesize and degrade it, choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) respectively, and nicotinic and muscarinic (M) receptors. Recently, we demonstrated the presence of M3, M4 and M5 receptors, and ChAT and AChE enzymes in human dendritic cells (DC). Given that the maturation process of the DC have a central role in the immune response, here we investigated the effect of cholinergic stimulation on the expression of maturation markers: HLA-DR and CD86 and the proinflammatory cytokines production, such as IL-12 and TNF-α, in these cells. DC were differentiated from positive selected CD14 mononuclear cells and cultured with IL-4 and GM-CSF during 5 days. Then cells were treated with the cholinergic agonist carbachol (Carb, 10 additional 24 h in the absence (immature DC (iDC)) or presence (mature DC (mDC)) of LPS (0.5 mg / ml). We observed that Carb increased the expression of HLA-DR and CD86, as well as the production of IL-12 (Carb: 575 ± 10; baseline: 374 ± 15(pg / ml)) and TNF-α (Carb: 6733 ± 1167, 3667± 629 baseline) in mDC (n = 3, P ≤ 0.01 Carb. vs. baseline). Both effects were reduced in the presence of the muscarinic antagonist atropine (10 pathway of M3 and M5 receptors and their product, nitric oxide, is an inflammatory mediator and an immune response regulator. We have shown by Western blot that iDC as well as mDC expressed NOS1 and NOS3 isoforms and had similar basal release of (uM) (iDC: 2.99 ± 0.96; mDC 1.98 ± 0.51). Carb treatment increased the levels of NO2-NO2(5.53 ± 0.18, p