Figure 4: Regulation of IL-23 expression by MAPK in Mtb-infected human monocytes. Monocytes were pretreated or not with p38 (SB203580) or ERK (PD98059) inhibitors for 30 min and afterwards were infected with Mtb as indicated. (a) After 8 hr, RNA was extracted and real-time RT-PCR was performed to measure the expression of TNF-α and IL-23p19 subunit transcripts. The results shown are from one out of three experiments performed with different donors that yielded similar results. (b) After 24 hr, the cell culture supernatants were collected, and the production of TNF-α and IL-23 was measured by CBA or ELISA assay. The results represent the mean ± SE of four independent experiments.