Role of type I IFN in IFN-γ secretion by sDCs.

Secretion of IFN-γ by sDCs is partially dependent on type I IFN. Purified sDCs (greater than 97% CD11c⁺) were cultured in either medium alone, medium plus 1000 neutralizing units of anti–IFN-α/β sheep immunoglobulin, or medium plus an equivalent volume of control sheep immunoglobulin for 18 hours. Supernatants were collected and analyzed for IFN-γ and IL-18 by ELISA. Data shown are for 1 representative experiment of 3.