Figure 1.

Thiol release by DCs is induced by T cells. Eight-day DCs (7 × 10⁴), untreated or treated for the last 24 h with LPS, were incubated 6 h alone (DCs; DCs-LPS) or with alloreactive T cells from a parallel primary 7-day MLR (DCs + alloT; DCs-LPS + alloT) or with T cells from a 7-day MLR between two uTs (DCs + uT) at a DC/T cell ratio of 1:10. As a control, DCs were fixed for 10 min with 1% glutaraldehyde before coculture with alloreactive T cells (GA-DCs + alloT). In a separate experiment (filled columns), DCs were cultured alone (DCs) or loaded overnight with tetox (DCs + tetox) and then incubated for 6 h with autologous tetox-specific T cells at the same DC/T cell ratio (DCs + tetox + tetoxT). At the end of the incubation, thiols present in the supernatants were evaluated by DTNB colorimetric assay. As a control, thiol release by the same number of alloreactive (alloT) or tetox-specific T cells (tetoxT) is shown. One representative experiment of six is shown ± SD.