Production of cytokines by dendritic cells (DC). Bone marrow, spleen and lymph node-derived DC were either unpulsed (open box) or pulsed with rV (solid box), rF1 (/hatched box), rV + rF1 (\hatched box) for 2–24 h. Supernatants were collected and assayed by enzyme-linked immunosorbent assay (ELISA) (a,b,c). Production of interleukin (IL)-10 (a); IL-4 (b); IL-12 (c) in 3-, 8- and 13-day-old bone marrow-derived DC (BMDC) are shown from triplicate experiments except for the day 13 IL-4. No IL-4 was seen in 3- and 8- and only intermittently in 13-day-old BMDC and the result from one positive experiment of three is shown (b). Production of IL-10 (d); interferon (IFN)-γ (e) and IL-12 (f) in splenic (d–f) and lymph node DC (g–i).