Fig 1. Differential IFN-λR expression and IFN-λ3 binding among primary human immune and epithelial cells.

A) Normalized expression values for each subunit of the IFN-λR as determined by RT-qPCR for normal human bronchial epithelial cells (NHBE), primary hepatocytes (hep) or immune cells purified from healthy human donor blood. Graph shows mean + SEM from 3–7 different donors for each population. Results were normalized to the geomean of HPRT1 and RPL13A reference genes. B-H) IFN-λ3 binding was quantified via flow cytometry as described in the Materials and Methods. B) Dose curves of adding 1, 2 or 5 μg/ml IFN-λ3 to epithelial cells or total human PBMCs. 0 μg/ml IFN-λ3 refers to adding the secondary antibody alone. Graph shows mean +/- SD for 3–7 different donors. C) Binding percentages as detected by flow cytometry for IFN-λ3 or a similarly His-tagged control protein (OBCAM) where means +/- SD are shown. D-H) Quantified IFN-λ3 (5 μg/ml) binding percentages to each cell type where each dot represents a different healthy individual and background binding of the secondary antibody alone was subtracted. In D), statistical significance results were identical when comparing either NHBE or hep to all other immune cell subsets. All comparisons are shown in S1 Table. H) Pearson correlation coefficients (r) calculated when comparing IFN-λ3 binding to different immune cell subsets. All comparisons are shown in S2 Table. *, P<0.05, ***, P<0.001, ****, P<0.0001, two-way (C) or one-way (D, G) ANOVA with Tukey’s multiple comparisons test, paired t-test (E-F).