IL-28B is a Key Regulator of B- and T-Cell Vaccine Responses against Influenza
(A) Analysis of H1N1-stimulated Th1 cytokine release in transplant recipients (n = 36) from post–vaccine samples in relation to IL-28B pre-treatment. Peripheral blood mononuclear cells (PBMCs) were pre-treated with recombinant IL-28B (100 ng/mL) for two hours prior to overnight stimulation with inactivated Influenza A H1N1 (0.3 µg/mL hemagglutinin). The expression profile of 17 cytokines was determined using a luminex-based platform. Key representative Th1 cytokines are shown. Wilcoxon matched-pairs signed rank (WCR)-test determined statistically significant differences between groups. Before-after plots are shown where each dot is a different patient. (B) PBMCs from transplant recipients were pre-treated with recombinant IL-28B (100 ng/mL) for two hours prior to overnight stimulation. Frequencies of H1N1-specific IL-4-producing CD4+ T-cells were measured by intracellular flow cytometry as described in Methods. Data from 47 transplant recipients are shown in PBMC collected pre- and post-vaccine. (C) PBMCs from transplant (Tx) recipients were pre-treated with recombinant IL-28B (100 ng/mL) for two hours prior to 5-day stimulation with H1N1. The production of H1N1-induced IgG is shown according to pre-treatment groups. Data from 38 transplant recipients are shown.