Fig. 1. P. acnes strains associated with acne disease induce significant IL-17 responses.

(a) PBMCs were cultured (2-5 × 10⁶/well) in the presence of live P_A and P_H strains (1MOI). Levels of IL-17 accumulated in the culture supernatants were measured using ELISA. Results from three donors were combined and the variation demonstrated as mean ± SD. (***p ≤ 0.001 compared to P_H associated strains). (b) For Sterile cell sorting, PBMCs were stimulated with P_H and P_A strains (1MOI) for 16 h and IL-17 secretion determined using a cytokine secretion capture assay. The cells were further stained with α-CD4 antibodies, and the CD4⁺IL-17⁺ cells were sorted under sterile conditions and cloned at 0.3cells/well. Each panel is representative of four independent experiments.