For ex vivo culture, skin samples from healthy participants were stored at 4–8 °C and processed within 24 h of surgery. Full‐thickness (3‐mm) punch biopsies (five replicates per treatment) were excised and placed in supplemented EpiLife medium (ThermoFisher Scientific, Waltham, MA, USA) in 96‐well tissue‐culture plates in a humidified incubator at 37 °C with 5% CO2. Stimulation was performed for 24 h with IL‐17 family cytokines as indicated.
Primary human keratinocytes were isolated from the skin of healthy adult donors (AppendixS1 ; see Supporting Information) and cultured in supplemented EpiLife medium (ThermoFisher Scientific) in a humidified incubator at 37 °C with 5% CO2.
Cells were stimulated for 48 h with a combination of IL‐17 family cytokines in the presence of TNF, as indicated. For all samples treated with brodalumab, cells were preincubated with brodalumab for 30 min at 37 °C prior to cytokine addition. For all samples treated with ixekizumab, ixekizumab was preincubated with cytokine mixtures for 30 min at 37 °C before addition to the cells. Recombinant human cytokines were purchased from R&D Systems [Minneapolis, MN, USA (IL‐17A: #317‐ILB; IL‐17C: #1234‐IL; IL‐17E: # 1258‐IL; IL‐17F: #1335‐IL; IL‐17A/F: #5194‐IL; TNF: 210‐TA)].
Primary human keratinocytes were isolated from the skin of healthy adult donors (Appendix
Cells were stimulated for 48 h with a combination of IL‐17 family cytokines in the presence of TNF, as indicated. For all samples treated with brodalumab, cells were preincubated with brodalumab for 30 min at 37 °C prior to cytokine addition. For all samples treated with ixekizumab, ixekizumab was preincubated with cytokine mixtures for 30 min at 37 °C before addition to the cells. Recombinant human cytokines were purchased from R&D Systems [Minneapolis, MN, USA (IL‐17A: #317‐ILB; IL‐17C: #1234‐IL; IL‐17E: # 1258‐IL; IL‐17F: #1335‐IL; IL‐17A/F: #5194‐IL; TNF: 210‐TA)].