Materials

Soybean phosphatidylcholine (SPC) (phospholipon 90 G, purity >90%) was a gift from Phospholipid/Natterman, Germany. Sodium cholate (NaChol), 1,2-Dimyristoyl-sn-glycero-3-phosphoethanolamine-N-(Lissamine™ rhodamine B sulfonyl) (Rh-PE), Sephadex G-75, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), aluminiumnitrat nonahydrat (Al(NO₃)₃ x 9H₂O), 2,2'-Azino-bis(3-Ethylbenzthiazoline-6-Sulfonic Acid) (ABTS), Lipopolysaccharides from Escherichia coli (LPS) and horseradish peroxidase conjugated anti-mouse IgA antibody were from Sigma-Aldrich (St Louis, MO, USA). Anti-mouse IgG1 and IgG2a were from Santa Cruz Biotechnology. Horseradish peroxidase conjugated anti-mouse IgG was from Chemicon International Millipore. Roswell Park Memorial Institute (RPMI) 1640 and modified Eagle’s medium (MEM) were from Gibco®, Life Technologies (New York, USA). Fetal calf serum (FCS), antibiotic/antimycotic solution (penicillin 10,000 IU/ml, streptomycin sulfate 10 mg/mL, amphotericin B 25 μg/ml), glutamine, and trypsin/ethylenediaminetetraacetic acid were from PAA Laboratories GmbH (Pasching, Austria). Complete RPMI (comp-RPMI) was prepared with RPMI 1640, 10% FCS, 5.5×10⁻⁵ M β-mercaptoethanol from Sigma-Aldrich, and antibiotic/antimycotic solution. Dendritic cell RPMI (DC-RPMI) was prepared with comp-RPMI plus 100 IU/ml of murine recombinant granulocyte-macrophage colony-stimulating factor (rmGM-CSF) (Pepro Tech, Rocky Hill, NJ, USA). All other chemicals and reagents were of analytical grade.