“…Four replicates of 3 × 10 5 cells/well were stimulated with naturally purified major allergens Phl p 1 (5 µg/ml) and Phl p 5 (5 µg/ml), purified protein derivative (PPD; 25 µg/ml; SSI, Copenhagen, Denmark) or medium control with or without blocking antibodies specific to the IL-10 receptor (aIL-10R: 5 µg/ml, clone 3F9; BD Biosciences, San Jose, Calif., USA), and TGF-β (aTGF-β 1, 2, and 3: 10 µg/ml, clone 1D11; R&D, Minneapolis, Calif., USA) or to the IL-4 receptor (IL-4R: 2.5 µg/ml, clone 25463.111; R&D). Allergens were purified from grass pollen extracts as described elsewhere [27] and concentrations of allergens were selected on the basis of previous studies on grass allergen-specific T cell responses [28,29]. Endotoxin levels were below 2.5 EU/ml in cultures with Phl p 5 and below 0.5 EU/ml in cultures with Phl p 1.…”