Fig. 4

Topoisomerase-I-specific CD4+ T cells show a Th17 polarized functional phenotype. a CD4+ T cell subsets were identified by flow cytometry using the combined surface expression of chemokine receptors CCR6, CXCR3, and CCR4. b After sorting, the different T helper subsets were stimulated with anti-CD3/CD28 beads for 48 h and secretion of IFNγ, IL-4, and IL-17A was measured in their supernatants by enzyme-linked immunosorbent assay (bars represent mean ± SE, n = 3). c The distribution of polarized T helper subsets within topo-I-specific CD4+ T cells (closed circles) is shown in comparison to the general CD4+ population (open circles). T test with Bonferroni correction was used for multiple comparisons. Lines indicate mean ± SD. d After sorting topo-I-specific CD4+ T cells according to their polarized T helper phenotype (range 16–2064 cells), mRNA expression levels of IFNγ, IL-4, and IL-17A were measured by qPCR using the Arcturus® PicoPure® RNA Isolation system, which is designed to recover high-quality RNA from a very low number of cells (10–500 cells) and to accomplish cDNA synthesis from minimal amounts of cDNA. IFNγ and IL-17A expression was calculated as fold change in reference to a mix of topo-I-reactive CD4+ T cells from three patients; IL-4 expression is reported as delta Ct from actin expression since it was not detectable in the reference population. Data are representative of four separate patients (mean ± SE)