Fig. 3

Characterization of the processing cell population. a L-tryptophan-induced production of interleukin-4. The processing cell population (pWB024 and pHW073 transfected in ratios (w:w) of 100:1 or 1000:1) was cultivated in InVitrus medium in the presence of increasing concentrations of L-tryptophan. After 48 h interleukin-4 was quantified in the cell culture supernatant. b Response to L-tryptophan and interleukin-4. HEK-293T cells were transfected for L-tryptophan-inducible SEAP production (pWB024 and pLMK116) and the cells were cultivated in InVitrus medium in the absence or presence of 50 μM L-tryptophan and 1 ng ml⁻¹ interleukin-4. After 48 h the production of the SEAP reporter was quantified in the culture medium. Data are means ± SD (n = 3)