For induction of transcription factors and cytokines, PBMC were cultured in a volume of 4 ml in sterile pyrogen-free 6-well culture plates (Falcon, Heidelberg, Germany). Cultures were stimulated for 1 h (EMSA) or from 0 h to 48 h (ELISA) with 1 or 100 μg per 106 cells of GP, with 250 ng/106 cells TSST-1 (Toxin Technologies, Sarasota, FL, USA) or with 250 ng/106 cells wild-type LPS from Escherichia coli serotype 0111:B4 (Sigma, Munich, Germany). In costimulatory experiments, PBMC were supplemented simultaneously with a combination of GP and TSST-1 or with a combination of GP and LPS.