July 25, 2019
Journal Of Medicinal Chemistry
Product: ULTRA PURE LPS from Escherichia coli O111:B4
Human PBMC Synergy Assays:
Human peripheral blood mononuclear cells were isolated using single step FicollPaque method, then washed three times to remove platelets and resuspended in RPMI-1640 supplemented with 10% HI-FCS, 2 mM L-glutamine, 2.5 mM HEPES + penicillin/streptomycin) at 10000 cells/well in 96- well flat bottom plate. Several pilot experiments (minimum of four different donors, and typically six) were performed using a full dose response of ligand to define the range of the EC10 to EC30 of MDP (Invivogen TLRL-MDP) and Pam2CSK4 (Invivogen TLRL-pca2-1), respectively, as it was determined that this was the concentration needed to reliability and consistently demonstrate synergy using both ligands. Typically, three concentrations of each of the two ligands were evaluated in a pairwise matrix to account for minor variations between donors, and also a full doseresponse was assessed to compare to the average of all donors tested. Compounds were preincubated for 30 min, and then ligands were added, and plates were incubated for 4 h at 37 C with 5% CO2. Supernatants were assessed for human proinflammatory cytokines using an MSD four plex kit (K15025C-4). Raw data were converted to cytokines concentrations using a four-parameter curve fit with 1/y2 weighting as recommended by the manufacturer using PerkinElmer Workout software. Cytokine values were then graphed into dose response curves using Sigma Plot software and an IC50 was determined for individual and composite graphs. The synergistic response was compared to the response of each of the ligands alone for each donor. A similar approach was also used for MDP and Ultrapure LPS (List Biologicals 421), MDP and Flagellin (Invivogen TLRL-stfla), and last MDP and IL-1ineb (Biolegend 57006).
• Product #421 – ULTRA PURE LPS from Escherichia coli O111:B4