NK cells conditioned with IL-2 or IL-12 instruct DCs to prime a Th1 response. (A,B) MLRs were performed with purified DCs and naive allogeneic CD4⁺ T cells. IL-2 (A) and IFN-γ (B) were measured in MLR supernatants by ELISA after 2 (A) or 5 days of coculture (B). Means plus or minus SD of triplicate of 1 representative experiment of 3 performed. (C) MLRs were performed with purified DCs and autologous CD4⁺ naive T cells. Cytokines were measured in MLR supernatants by ELISA after 5 days of coculture. Data represent means plus or minus SD of triplicates of 1 representative experiment of 3.