PI 3-kinase and ROS involvement in the activation and cytokine production of monocytes. Aliquots of monocytes were incubated for one hour with the PI 3-kinase inhibitor LY294002 (10 μM), or with the antioxidant NAC (5 mM), and thereafter exposed to PSK or Trx80 for 12 hours. DCFH-DA (5 μM) was added during the final 1-hour incubation to 1 aliquot of the PSK-treated monocytes. (A) Flow cytometry FACS analysis of DCFH-DA, which indicates ROS production. Monocytes without treatment, PSK treated, NAC + PSK treated are indicated by 1, 2, and 3, respectively. The results show 1 of 4 experiments. (B) The treated monocytes were reintroduced to the EBV-infected monocyte-depleted cultures. (i) PSK-exposed monocytes. (ii) Trx80-exposed monocytes reintroduced to the cultures. After 48 hours, the culture media were collected and analyzed for IL-15 and IL-12 content. *P < .05 and **P < .01 as compared with cultures to which PSK-exposed (i) or Trx80-exposed (ii) monocytes were re-introduced. The results represent mean ± SD of 3 independent experiments; the cell populations were tested for SAP expression. The results show 1 of 3 experiments.