Anne-Pauline Bellanger1, Jean-René Pallandre2, Houssein Gbaguidi-Haore3, Jenny Knapp4, Noémie Malézieux5, Thibaud Lignon5, Christophe Borg2, Laurence Millon6. 1. Parasitology-Mycology Department, Besançon University Hospital, F-25000 Besançon, France; Franche-Comté University, F-25000 Besançon, France; CNRS 6249 /UMR "Chrono-environnement", F-25000 Besançon, France. Electronic address: apbellanger@gmail.com. 2. Inserm U1098, EFS Bourgogne Franche-Comté, University of Franche-Comté, IFR133 Besançon, France. 3. Infection Control Department, Besançon University Hospital, F-25000 Besançon, France. 4. Parasitology-Mycology Department, Besançon University Hospital, F-25000 Besançon, France; CNRS 6249 /UMR "Chrono-environnement", F-25000 Besançon, France. 5. Parasitology-Mycology Department, Besançon University Hospital, F-25000 Besançon, France. 6. Parasitology-Mycology Department, Besançon University Hospital, F-25000 Besançon, France; Franche-Comté University, F-25000 Besançon, France; CNRS 6249 /UMR "Chrono-environnement", F-25000 Besançon, France.
Abstract
CONTEXT AND OBJECTIVES: Alveolar echinococcosis (AE) is a severe chronic helminthic disease that mimics slow-growing liver cancer. Previous studies using murine models suggest that Echinococcus multilocularis (Em) metacestodes have developed mechanisms which impair the natural inflammatory host response. The aim of this study was to investigate in vitro the impact of Em vesicular fluid (VF) on monocytes, monocytes derived dendritic cells and lymphocytes from healthy blood donors. METHODS: First, assays were performed to investigate whether or not Em-VF influences monocyte-derived dendritic cell (MoDC) differentiation and maturation. Monocytes during differentiation and immature MoDCs were exposed to Em-VF. The effect of Em-VF was assessed using flow cytometry (CD86, CD83, CD80) and immune assays (IL-10 and TGFβ). Second, assays were performed to investigate the interaction between Em-VF, peripheral blood monocyte cells (PBMC) and Toll-like Receptor (TLR) agonists (LPS, PolyIC, R848 and CpG). PBMC were stimulated by each of the TLR agonists with and without Em-VF. The subsequent TGFβ production was assessed. RESULTS: Exposure to Em-VF had bearing on both differentiation and maturation of MoDC, but only partially. A decrease in the expression of co-stimulatory molecules was observed; however, levels of immune-regulatory cytokines were stable. PBMC exposed simultaneously to Em-VF and LPS induced a significant increase of TGFβ (p<0.05, Wilcoxon signed-rank test). Further experiments showed that TGFβ production was lymphocyte-dependent. CONCLUSION: The assays performed confirmed that Em-VF influences the host immune response. However, only minor changes were observed when investigating the Em-VF impact on cells from healthy blood donors. Assays with TLR agonists suggested that co-stimulation with LPS reinforces the response of healthy blood donors exposed to Em-VF.
CONTEXT AND OBJECTIVES:Alveolar echinococcosis (AE) is a severe chronic helminthic disease that mimics slow-growing liver cancer. Previous studies using murine models suggest that Echinococcus multilocularis (Em) metacestodes have developed mechanisms which impair the natural inflammatory host response. The aim of this study was to investigate in vitro the impact of Em vesicular fluid (VF) on monocytes, monocytes derived dendritic cells and lymphocytes from healthy blood donors. METHODS: First, assays were performed to investigate whether or not Em-VF influences monocyte-derived dendritic cell (MoDC) differentiation and maturation. Monocytes during differentiation and immature MoDCs were exposed to Em-VF. The effect of Em-VF was assessed using flow cytometry (CD86, CD83, CD80) and immune assays (IL-10 and TGFβ). Second, assays were performed to investigate the interaction between Em-VF, peripheral blood monocyte cells (PBMC) and Toll-like Receptor (TLR) agonists (LPS, PolyIC, R848 and CpG). PBMC were stimulated by each of the TLR agonists with and without Em-VF. The subsequent TGFβ production was assessed. RESULTS: Exposure to Em-VF had bearing on both differentiation and maturation of MoDC, but only partially. A decrease in the expression of co-stimulatory molecules was observed; however, levels of immune-regulatory cytokines were stable. PBMC exposed simultaneously to Em-VF and LPS induced a significant increase of TGFβ (p<0.05, Wilcoxon signed-rank test). Further experiments showed that TGFβ production was lymphocyte-dependent. CONCLUSION: The assays performed confirmed that Em-VF influences the host immune response. However, only minor changes were observed when investigating the Em-VF impact on cells from healthy blood donors. Assays with TLR agonists suggested that co-stimulation with LPS reinforces the response of healthy blood donors exposed to Em-VF.