Figure 4.

Naive CD4⁺ T cells from HIES patients fail to differentiate to the Th17 lineage in vitro in response to the STAT3-activating cytokines IL-6 and IL-23. Naive CD4⁺ T cells isolated from a normal donor (▪, □) and a HIES patient (▴, ▵) were cultured with anti-CD2, anti-CD3, and anti-CD28 mAb-coated beads either alone (CD3) or in the presence of IL-1β plus IL-6 (IL-1β+IL-6), IL-23 (IL-23), or all three cytokines (IL-1β +IL-6+IL-23). The cells were harvested after 5 d and then recultured under the same conditions for another two rounds of stimulation. (A) IL-17A secretion was determined after either 3 d (▪, ▴; total time of culture, 12 d) or 6 d of the third round of restimulation (□, ▵; total time of culture, 15 d). (B) Expression of RORγt mRNA in cells stimulated for 5 d (▪, ▴) or 15 d (□, ▵) was determined by quantitative PCR.