Human DCs deficient in C1q have impaired production of IL-12p70 after CD40 ligation. (A,B) DCs from healthy donors (NDs 1 and 2) and C1q-deficient patients (C1q^−/− PTs 1 and 2) were cultured alone or stimulated with soluble CD40L (1-2 μg/mL) or LPS (0.1-1 μg/mL) for 48 hours. IL-12p70 and IL-10 were evaluated in the supernatants by ELISA.