Measurement of Cytokine Secretion
Sandwich enzyme-linked immunosorbent assay (ELISA) was performed using commercially available kits (eBioscience, human IL29 ELISA) to determine the amount of secreted human IFNλ in the cell-free supernatants of stimulated cells. Samples were tested in duplicates and the assays were performed according to the manufacturers' instructions. Cytokines were detected by measuring the absorbance at 490 nm with a 650-nm reference in a photometer (Sunrise reader, Tecan, Salzburg, Austria). Cytokine concentrations were calculated according to a standard dilution of the respective recombinant cytokines using Magellan V 5.0 software (Tecan, Salzburg, Austria).