Fig. 1.

Determining the inhibitory concentration of chemotherapeutic drugs inhibiting T cell proliferation. Dilution series of 1:2 were established for doxorubicin, cisplatin and irinotecan from their original concentrations. A total of 1 × 10⁵ peripheral blood mononuclear cells (PBMCs) were incubated with indicated concentration of chemotherapeutic drugs and staphylococcal enterotoxin B (SEB) 5 μg/ml in 37°C for 3 days, and 1 μCi of [³H]-thymidine/well was added 18 h prior to harvesting on day 4. Radioactivity [counts per minute (cpm)] was measured for doxorubicin (Fig. 1a), cisplatin (Fig. 1b) and irinotecan (Fig. 1c). Data shown are the means of quadruplicate determinations for each condition from three independent experiments.