FIG. 3.

A. actinomycetemcomitans-stimulated mDCs, but not macrophages, induced an early IFN-γ response in PBL. PBL with various numbers of autologous mDCs (A) or macrophages (B) from an NP patient were stimulated with 10⁵ A. actinomycetemcomitans cells. The supernatant fluids were collected after 1, 2, and 3 days, and IFN-γ production was measured by ELISA. Note the remarkable IFN-γ response induced in just 24 h by mDCs (A) but not by macrophages (B). In control cultures in which bacteria were used to stimulate DCs or macrophages alone, we were unable to detect any IFN-γ production. These data are representative of three separate experiments of this type and are expressed as means ± SE. MΦ, macrophages; Aa, A. actinomycetemcomitans.