Proinflammatory Modulation of the Surface and Cytokine Phenotype of Monocytes in Patients With Acute Charcot Foot

Despite increased information on the importance of an inappropriate inflammatory response in the acute Charcot process, there has been no previous attempt to define the specific pathways that mediate its pathogenesis. Here, the role played by monocytes was analyzed

Can we prevent or treat multiple sclerosis by individualised vitamin D supply?

Apart from its principal role in bone metabolism and calcium homeostasis, vitamin D has been attributed additional effects including an immunomodulatory, anti-inflammatory, and possibly even neuroprotective capacity which implicates a possible role of vitamin D in autoimmune diseases like multiple sclerosis (MS). Indeed, several lines of evidence including epidemiologic, preclinical, and clinical data suggest that reduced vitamin D levels and/or dysregulation of vitamin D homeostasis is a risk factor for the development of multiple sclerosis on the one hand, and that vitamin D serum levels are inversely associated with disease activity and progression on the other hand. However, these data are not undisputable, and many questions regarding the preventive and therapeutic capacity of vitamin D in multiple sclerosis remain to be answered. In particular, available clinical data derived from interventional trials using vitamin D supplementation as a therapeutic approach in MS are inconclusive and partly contradictory. In this review, we summarise and critically evaluate the existing data on the possible link between vitamin D and multiple sclerosis in light of the crucial question whether optimization of vitamin D status may impact the risk and/or the course of multiple sclerosis

Ruolo immunomodulatorio della 1,25(OH)2D3 con particolare attenzione ai pazienti affetti da epatopatia HCV-positiva

Introduzione. La forma attiva della vitamina D3, 1,25(OH)2D3, oltre alla classica funzione sulla mineralizzazione ossea svolge un’azione immunomodulatoria indirettamente dimostrata dalla presenza del recettore della Vitamina D (Vitamin D receptor, VDR) nel timo umano e nei leucociti periferici e dai disordini immunitari in animali e pazienti con deficit di vitamina D. 1,25(OH)2D3 produce: 1) Inibizione della maturazione delle CD attraverso un meccanismo VDR-dipendente; 2) Riduzione dell’espressione delle MHC di classe II, di CD80, CD86, CD40, CD1a e CD83; 3) Potente inibizione delle risposte di tipo Th1; 4) Emergenza di un predominante fenotipo Th2; 5) Inibizione produzione di IFN-g; 6) Inibizione di produzione di immunoglobuline IgM e IgG. Scopo dello studio. Sulla base di queste premesse si è concretizzato il progetto di ricerca sulla 1,25(OH)2D3 che si è svolto seguendo tappe successive: Parte prima. Effetto della 1,25(OH)2D3 sulla funzione dei monociti di soggetti sani, in particolare sulla capacità di inibire l’attività pro-infiammatoria CD40L-mediata. Parte seconda. Effetto della 1,25(OH)2D3 sulla capacità proliferativa e sulla produzione di citochine da parte dei linfociti di soggetti trapiantati per cirrosi epatica HCV-positiva. Parte terza. Studio degli effetti clinici prodotti dalla supplementazione con 1,25(OH)2D3 in soggetti affetti da epatopatia cronica da virus C. Materiali e metodi. Pazienti. Parte prima. Dodici donatori sono stati inclusi nello studio. Parte seconda. Sedici pazienti trapiantati per cirrosi da virus C fra il 1995 e il 2004 presso il nostro Centro e 10 controlli sani sono stati arruolati nello studio. Parte terza. Sette pazienti di cui sei affette da epatite cronica da virus C e una con ricorrenza di malattia da virus C dopo trapianto di fegato sono state incluse nello studio. Cellule. Le cellule mononucleate da sangue periferico (PBMC) sono state separate mediante centrifugazione su gradiente di densità. I monocito-macrofagi sono stati successivamente purificati mediante centrifugazione contro-corrente. Le cellule T sono state isolate dalle PBMC attraverso un processo di selezione negativa usando biglie magnetiche. Le cellule sono state coltivate in RPMI con aggiunta di 1,25(OH)2D3 a concentrazioni comprese fra 0.001 e 10nM. Per la stimolazione è stato utilizzato CD40L trimerico solubile ricombinante, la PHA, il CD3/CD28 e la PMA/IO per gli esprimenti di citofluorimetria. La produzione intracellulare di citochine e l’espressione di membrana di CD3, CD4,CD40, CD86 e CD80 sono state valutate al citofluorimetro (FACS). Risultati. Parte prima. 1,25(OH)2D3 inibisce la risposta citochinica dei monociti CD40L-attivati, inibisce la produzione di TNF-α e IL-1β, riduce l’espressione delle molecole di superficie, nterferisce con l’abilità da parte del CD40L di indurre funzioni di costimolo. Parte seconda. 1,25(OH)2D3 inibisce la proliferazione linfocitaria T in modo dose-dipendente e la duzione di IFN-g e TNF-α nei pazienti trapiantati. Non sono state trovate correlazioni significative fra i livelli sierici di 25(OH)D e la risposta proliferativa T cellulare o la produzione citochinica PMA/IO indotta. Parte terza. La supplemetazione con 1,25(OH)2D3 produce una significativa riduzione dell’IFN-γ plasmatico nelle pazienti HCV positive. Discussione. 1,25(OH)2D3 esplica un’azione immunomodulante di alcune importanti vie di attivazione immunitaria. Gli effetti sono dose-dipendenti. 1,25(OH)2D3 produce effetti nei linfociti T di pazienti trapiantati per cirrosi epatica da virus C. Questi effetti sono simili a quelli ottenuti nei controlli. I risultati preliminari ottenuti mediante supplementazione con 1,25(OH)2D3 nei pazienti HCV-positivi hanno mostrato alcuni dati incoraggianti.Background. In addition to the classical mineralizing action, the active form of Vitamin D3, 1,25(OH)2D3, has also an immunomodulatory function, as suggested by the presence of Vitamin D receptor (VDR)in human thymus and in peripheral leukocytes, and by the immune disorders in subjects with Vitamin D defects. 1,25(OH)2D3 leads to: 1) Inibition of dendritic cell maturation; 2) Reduction of the expression of MHC class II molecules, CD80, CD86, CD40, CD1a and CD83; 3) Powerful inhibition of type Th1 responses; 4) Predominance of Th2 phenotype; 5) Inhibition of IFN-g production; 6) Inhibition of IgM and IgG production. Aims. To study: First: the effect of 1,25(OH)2D3 on monocyte function, in particular on the inhibitory function on CD40L-mediated pro-inflammatory activity. Second: The effect of 1,25(OH)2D3 on proliferation and cytokine production of lymphocytes from HCV-positive transplanted patients. Third: The clinical effects of 1,25(OH)2D3 supplementation in HCV-positive chronic hepatopathic patients. Material and methods. Peripheral blood mononuclear cells were obtained by centrifugation over Ficoll-Hypaque density gradient solution. The effect of VitD3 to affect the ability of CD40L to induce tumour necrosis factor (TNF)-α, and interleukin (IL)-1b production and to up-modulate surface expression of CD40, CD80 and CD86 was evaluated in three days old monocyte. Also, the effect of VitD3 to down-regulate the co-stimulatory activity of CD40L-stimulated monocytes was studied in T lymphocytes stimulated by immobilized anti-CD3. Surface markers expression and cytokine production was evaluated by FACS. To assess proliferation, T lymphocytes were stimulated with phytohemagglutinin (PHA) in the presence or absence of vitD3 and pulsed at day 4 with 3H-thymidine for 18 hours. The effect of vitD3 on intracellular interferon (IFN)-g, tumour necrosis factor (TNF)-α production was evaluated by FACS in T lymphocytes after either phorbol 12-myristate 13-acetate (PMA)/Ionomicin stimulation. Results and Conclusions. 1,25(OH)2D3 exherts modulatory effects on important immune activation pathways. These effects are dose-dependent. 1,25(OH)2D3 has immunomodulatory effects on T-lymphocytes of patients transplanted for HCV-positive liver cirrosis. These effects are similar in patients and controls. Preliminary data on 1,25(OH)2D3 supplementation in HCV-positive patients have shown encouraging results

1alpha,25-dihydroxyvitamin D3 inhibits CD40L-induced proinflammatoryand immunomodulatory activity in Human Monocytes

CD40 ligand (CD40L) stimulation induces proinflammatory and immunomodulatory activity in monocytes. Here, we report on the effects of the steroid hormone 1a,25-dihydroxyvitamin D3 (1,25D3) on human blood monocytes that have been stimulated with the CD40L ligand. Co-treatment of CD40L-stimulated monocytes with 1,25D3 resulted in reduced production and secretion of tumor necrosis factor (TNF)-a and interleukin (IL)-1b, as well as in reduced expression of the surface co-stimulatory molecules CD80 and CD86. In addition, costimulation of CD4+ T lymphocytes by monocytes co-treated with CD40L and 1,25D3 resulted in reduced cell proliferation and diminished interferon (IFN)-c but enhanced IL-10 production by CD4+ T cells. Finally, 1,25D3 interfered with the ability of CD40L to rescue monocytes from apoptosis induced by serum withdrawal. These findings suggest that 1,25D3 may regulate the interaction of monocytes with T cells or other cell types that express CD40L, thus influencing the outcome of the immune or inflammatory response

Nonsteroidal anti-inflammatory drug metabolism potentiates interferon alfa signaling by increasing STAT1 phosphorylation

A sustained response to standard interferon therapy for chronic hepatitis C has been demonstrated in no more than 25% of patients. To improve interferon alfa (IFN-alpha) antiviral effect, a number of combination therapies with IFNs plus other drugs have been proposed for both relapser and nonresponder hepatitis C virus (HCV)-infected patients. Although the causes of IFN resistance in subsets of HCV-infected patients are unknown, both viral and host factors have been involved, including defects in IFN signal transduction and IFN-alpha/beta receptor down-regulation. Here, we report that nonsteroidal anti-inflammatory drugs (NSAIDs), which have been proposed for IFN-alpha combination therapy in nonresponders, potentiate IFN-alpha signaling. We found that, in the hepatoma cell lines, CCL13/Chang and HepG2, indomethacin, a selective cyclo-oxygenase 1 and 2 (COX-1 and COX-2) inhibitor, increases IFN-alpha stimulation of interferon-stimulated response element (ISRE)-dependent transcription in a dose-dependent manner. interestingly, maximal potentiation was observed with suboptimal IFN-alpha concentrations. Indomethacin exerts its effects by synergizing with IFN-alpha in inducing STAT1 activation by phosphorylation, without affecting concurrent Jak1 phosphorylation, Our data indicate that blockade of arachidonic acid (AA) metabolism by indomethacin activates a signaling pathway that converges on STAT1 activation to potentiate IFN-alpha-dependent gene activation