FIG. 4.

Early ssRNA or LPS priming suppresses late IL-12p70 response of DCs to LPS but not to CD40LT. Freshly purified blood monocytes were cultured with GM-CSF and IL-4 to induce DC differentiation. (A) Medium (none), 10 ng/ml LPS, or 500 ng/ml ssRNA was added at the beginning of the culture (day 0). (B) On day 5 (d5), cells either were left in medium or were stimulated with 10 ng/ml LPS or 200 ng/ml CD40LT. (C) On day 5, cells either were left in medium or were stimulated with 200 ng/ml CD40LT. The amounts of IL-10, IL-12p70, and TNF-α released during the 24 h following stimulation were determined by ELISA: culture supernatants were collected on day 1 (A) or day 6 (B and C).