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Statins were shown to possess immunomodulating properties, but the mechanisms of statin effects on the immune system are poorly understood. We analyzed the influence of statins on professional antigen-presenting dendritic cells (DC). Immature DC were cultivated from monocytes of healthy donors. DC maturation was induced by lipopolysaccharide (LPS; 1 microg/mL). Unstimulated and LPS-stimulated DC were treated with simvastatin or atorvastatin (0.1-1 microM). The expression of CD40, CD83, CD86, and human leukocyte antigen-DR on unstimulated and LPS-stimulated DC was reduced significantly by statins, and the expression of Toll-like receptor 2 (TLR2) and TLR4 on LPS-stimulated DC was enhanced temporarily. Statins caused a significant reduction of endocytosis of fluorescein isothiocyanate-dextran by DC. Statins significantly inhibited the basal secretion of interleukin (IL)-6, IL-8, IL-12, and tumor necrosis factor alpha from unstimulated DC, and their release from LPS-stimulated DC was enhanced. In mixed leukocyte reaction, preincubation of LPS-stimulated DC with statins significantly suppressed their clustering with T cells and their ability to induce T cell proliferation, CD71, and CD25 up-regulation on T cells and the secretion of interferon-gamma and IL-2 from T cells. In conclusion, this study showed that statins suppressed endocytosis, basal secretion of proinflammatory cytokines, and the ability of DC to induce T cell proliferation, activation, and T helper cell type 1 differentiation. However, statin preincubation of LPS-stimulated DC caused a further increase in their secretion of proinflammatory cytokines.

Immunomodulating therapies may prevent relapses in multiple sclerosis and stabilize neurological status. However, little is known about the influence particularly of newer drugs on cognitive functions. We conducted an open-label prospective study to demonstrate whether natalizumab is apt to improve cognitive functions and mood in 29 patients tested psychometrically while under treatment for 6 months. We found improvements in some measures of attention, memory, mood, and well-being, but no deterioration, although patients suffered from their diseases for more than 10 years and had an EDSS score of 3.5. It is concluded that natalizumab is able to stabilize or improve cognition and mood even in longer-lasting multiple sclerosis.

Angiotensin-converting enzyme (ACE) inhibitors interfere with several key events of vascular inflammation resulting in impressive reductions in coronary vascular events. However, in human arteries ACE inhibitors block the production of angiotensin II (AngII) incompletely because of the involvement of alternative pathways in local AngII formation. Therefore, our study concentrated on the presumed modulation by ACE inhibition of local AngII-mediated inflammatory actions by a mechanism independent of blockage of AngII formation. We analyzed the effect of the ACE inhibitor ramiprilat on AngII-dependent cell adhesion molecule (CAM) expression and adhesion of monocytic THP-1 cells to endothelial cells. AngII induced upregulation of P-selectin, VCAM-1 and ICAM-1 on endothelial cells via activation of AT1, which was correlated with enhanced THP-1 adhesion in flow chamber assays. Both enhanced adhesion and adhesion molecule expression were significantly reduced by pretreatment with ramiprilat. Ramiprilat reduced AT1 expression on endothelial cells and decreased the AngII-induced p65 translocation into the nucleus. Diminished AT1 expression and adhesion molecule expression in response to ramiprilat treatment were partially reversed after incubation with a bradykinin 2 receptor antagonist, suggesting that elevated bradykinin levels under ACE inhibition may be involved in the beneficial effect of ACE inhibitors. Thus, modulation of the local AngII system by ramiprilat may at least in part contribute to the benefits of ACE inhibition in the treatment of atherosclerotic diseases.