Expression of IFN-λ1 receptor, IL-28Rα, by human naive and memory T cells. (A) Phenotype of purified human naive and memory T cells. Populations of PBMCs (top), purified naive (middle) or memory (bottom) T cells were stained with the indicated antibodies and analyzed by flow cytometry to assess purity. Numbers indicate percentage of naive or memory T cells which coexpress CD45RA, CD3, CD4, and CD45RO. The purity of naive and memory T cells was at least 95%. Results are from a representative routine experiment. (B) Detection of IL-28 Rα by real-time PCR. Total RNA was harvested from naive and memory T cells and from PBMCs. The levels of IL-28Rα mRNA expression were determined by real-time PCR. PBMCs were used as positive controls. Negative controls included both non-RT and nontemplate control (data not shown). Results (shown as means ± SDs) from 3 individual donors are presented as ΔCT, with lower values representing higher levels of mRNA.