DCs highly susceptible to HIV-1_BaL infection produce less IL-12 p70 than DCs more resistant to infection. Immature DCs were exposed to 10 × HIV-1_BaL for 72 hours with CD40L stimulation during the final 6 hours (TNFα) or 24 hours (IL-12 p70). The figure shows intracellular cytokine production in p24^- and p24⁺ DCs after no stimulation (medium), HIV-1_BaL exposure alone, CD40L stimulation alone, or HIV-1_BaL exposure followed by CD40L stimulation in 3 different donors (A, B, and C, respectively). The figure shows data representing donors with an intermediate susceptibility to HIV-1_BaL infection (A), a high susceptibility to HIV-1_BaL infection (B), and a low susceptibility to HIV-1_BaL infection (C), and their IL-12 p70 and TNFα production after CD40L stimulation. Gates were set on large CD1a⁺ CD3^- cells. Numbers indicate frequency of stained DCs.