FIG. 4.

Macrophage responses to CpG ODNs. The RAW 264.7 macrophage cell line (A), primary C57BL/6 BM-derived macrophages (B), and peritoneal exudate macrophages (C) were activated overnight with recombinant IFN-γ (10 U/ml) prior to stimulation with the indicated ODNs at 1 μM or with 100 ng of LPS/ml as the positive control. RAW cells cultured with IFN-γ alone (10 U/ml) served as the negative control (Med). NO levels were determined using the Griess reaction, and cytokine levels were determined using conventional ELISAs (BioSource). Results are representative of four (A and B) or two (C) experiments..