IL-28B is a Key Regulator of B- and T-Cell Vaccine Responses against Influenza
(A–D) PBMCs from healthy volunteers were pre-treated with 1 ng/mL, 10 ng/mL, or 100 ng/mL rIL-28B for two hours prior to 5-day (A–C) or 7-day (D) stimulation with H1N1. Kruskal Wallis-test was used to determine statistically significant differences. (A) Cytokine profile after stimulation with H1N1 according to pre-treatment groups (n = 9). (B) B-cell proliferation was quantified using Cell Trace Violet proliferation dye staining. CD20 and CD27 served as cell-type and memory markers, respectively (n = 6). (C) Total amount of IgG in supernatants in an independent cohort of HVs was determined using by ELISA (n = 8). (D) The amount of H1N1- and HA-H1N1-specific IgG in supernatant was determined by ELISA (n = 9, and n = 8 (1 donor did not produce HA-specific IgG) respectively). The reduction of pre-to-post-treated PBMCs was calculated.