Requirement of monocytes for the effect of PSK and Trx80. In panels A and C, T-cell activation was detected by SAP expression, as in Figure 1. (A) EBV-infected CBMC total and monocyte-depleted populations were cultured with PSK (25 μg/mL) or Trx80 (100 nM) as indicated. Cells from 3- and 6-day-old cultures were tested. The results show 1 of 4 experiments. (B) B-cell outgrowth was determined as in Figure 2. EBV-infected CBMC total and monocyte-depleted populations were cultured with Trx80 or with PSK. The results are shown in the following order: total population without, with Trx80, or with PSK; monocyte-depleted population without, with Trx80, or with PSK. Error bars indicate SD of triplicate cultures. One further experiment showed similar results. (C) Monocyte-depleted CBMCs were infected with EBV. Aliquots of the isolated monocytes were treated for 20 hours with PSK, IFN-γ (500 U/mL), Trx80, or Trx80 + PSK. They were reintroduced to the monocyte-depleted cultures. The results show 1 of 5 experiments.