ISS induces activation of FL-DCs.

(A,B) CD11c⁺ cells isolated from the spleens of FL-treated mice were incubated overnight in CM and GM-CSF. (A) Histograms show the coexpression of IA-b, CD80, CD86, and CD54 on CD11c⁺ gated cells cultured in the presence (dotted line) or absence (black line) of ISS (10 μg/mL). Results shown are representative of 6 different experiments. (B) Cytokine profile of DCs treated with ISS (10 μg/mL) and C-ODN (10 μg/mL) compared to untreated DCs. These results represent the mean of 3 different experiments. (C,D) CD11c⁺DCs isolated from the popliteal and inguinal lymph nodes of FL-ISS (●), FL–C-ODN (○), FL alone (▴), or untreated animals (▵) were irradiated (3000 rads) and cultured with 3 × 10⁵allogeneic spleen cells. ⋄ indicates DC alone; ♦, T cell alone. Cell proliferation (C) and IFN-γ secretion in the supernatant (D) of the DC/spleen cell coculture were measured after 4 days of culture. These results are the mean of 3 different experiments. (E) Purified spleen-derived NK cells were cultured in the presence of ISS (▴), C-ODN (▵), or IL-12 (●), or in the presence of ISS-treated FL-DCs (▪), C-ODN–treated FL-DCs (■) or untreated FL-DCs (♦). After 24 hours of culture, viable lymphocytes were tested against the YAC-1 cell line in an immunocytotoxicity assay. These data represent the mean of 3 different experiments.