Figure 2.

HERA-CD27L enhances human T cell activation following stimulation in vitro. (A,B) Naïve CD4+ or CD8+ T cells were isolated from the peripheral blood of healthy volunteers, labeled with CFSE and stimulated with medium control or anti-CD3 antibody in the presence of HERA-CD27L, trimeric CD27L (both 100 ng/mL), or vehicle control (PBS), as indicated. On day 5 (CD4+) or day 4 (CD8+), T cells were harvested and examined by flow cytometry. Representative histograms (A) and quantified data (B) are shown. The p-values represent comparisons between samples using a one-way ANOVA plus post-hoc Bonferroni multiple comparisons test. ****p < 0.0001. Although not labeled, all groups were significantly different from the medium alone group. (C,D) Naïve CD4+ T cells were stimulated with anti-CD3 antibody or medium control in the presence/absence of HERA-CD27L (100 ng/mL), as indicated. On day 5, T cells were harvested, stained for surface expression of (C) CD357 (GITR) and CD134 (OX40) or (D) CD25 (IL-2Rα) and examined by flow cytometry. (E) Naïve CD4+ T cells were stimulated with anti-CD3 antibody in the presence/absence of HERA-CD27L (100 ng/mL), as indicated. On day 6, T cells were harvested, fixed, permeabilized, and stained for intracellular expression of IL-2, IFN-γ, and TNF-α and examined by flow cytometry. Numbers indicate the percentage of cells within the defined region. Representative histograms, gated on live single cells, from the median sample of triplicates from at least three independent experiments are shown.