Time course studies on the effect of IFN-λ1 on Th2 (IL-13) and Th1 (IFN-γ) production by bead-stimulated PBMCs. PBMCs were stimulated for 1 to 5 days with beads bound to anti-CD2, CD3, and CD28 antibodies, in the presence (■) or absence (□) of IFN-λ1 (100 ng/mL). The secretion of IL-13 (top panel) and IFN-γ (bottom) at each day was determined by ELISA. Result s are shown as means ± SDs.