Briefly, the DE52-purified parasites were resuspended in

Balts-buffer (50 mM sodium phosphate buffer, pH 5.5) and incubation on ice for 30 min followed by a 5-min incubation at 37°C. The solution was subsequently centrifuged (1400 rpm, 7 min, 4°C) and the supernatant treated with benzonase (VWR) to remove potential DNA/RNA contamination Selleckchem Obeticholic Acid (as described by the supplier). The supernatant was dialyzed against 10 mM Tris, pH 7.4, and the sVSG was purified using ion-exchange chromatography and gel filtration as described previously 79, 80. mfVSG was prepared as described previously 81. Prior to performing a size exclusion chromatography (equilibrated against 10 mM Tris, pH 7.4, containing 0.02% N-octylglucoside, Sigma-Aldrich), the mfVSG was treated with benzonase (similar as for sVSG) to remove potential nucleic acid contamination. The protein concentration of both VSGs was estimated spectrofotometrically by a detergent-compatible protein assay kit (Bio-Rad) using BSA as a standard. The purity of both sVSG and mfVSG was checked in SDS-PAGE and found to be >95%. In addition, Western blot analysis, using rabbit polyclonal anti-VSG and anti-cross-reacting determinant Abs confirmed the presence of the GPI anchor on mfVSG 82. Finally, the endotoxin levels were determined using the Limulus amebocyte lysate (LAL) test (Cambrex) according to the manufacturers’ instructions and found to be <0.5 pg/μg VSG. BM-DCs were generated as

described previously 83.

Briefly, BM-precursor cells were isolated from the hind limbs and seeded out in petri dishes (10 cm, Greiner) at 3×106 cells per dish. For microarray analysis, BM-precursor BGB324 ic50 cells were depleted of B and T cells by using anti-CD19 and anti-CD90 magnetic beads (Miltenyi Biotec), respectively. Cells were cultured in RPMI 1640 (PAA) supplemented with 10% heat-inactivated fetal calf serum (FCS, Acyl CoA dehydrogenase PAA), penicillin (100 U/mL; PAA), streptomycin (100 mg/mL; PAA), L-glutamine (2 mM; PAA) and β-mercaptoethanol (50 mM; Sigma-Aldrich). Culture medium was additionally supplemented with 10% supernatant from a GM-CSF-transfected cell line 84. At d7 or d8, BM-derived DCs were harvested and replated at a density of 106 cells/mL in a 24-well plate (nontissue culture treated; Greiner). For maturation analysis of cytokine production and surface marker expression, BM-DCs were cultured for 20–24 h in the presence of TNF (500 U/mL; PeproTech), LPS (Escherichia coli 0127:B8 0.1 μg/mL; Sigma-Aldrich), sVSG or mfVSG from clone AnTat1.1 (2 μg/mL), or sVSG MiTat1.5 (2 μg/mL). For in vivo polarization assays, BM-DCs were seeded at a density of up to 5×106 cells/mL, matured for 4 h only with different maturation stimuli and additionally loaded with 40 μg/mL MOG35–55-peptide (synthesized and HPLC purified by R. Volkmer, Charité, Berlin, Germany), 10 μM OVA-peptide327–339 (Activotec) or 50–100 μg/mL OVA protein (endotoxin-free; Hyglos) as indicated.