Fig. 2

Moderate functional differences in polyclonally stimulated CD4 T cells of control subjects (HC) and patients with rheumatoid arthritis (RA). a Cytokine-expressing CD4 T cells of HC (gray), patients with RA (white), and patients with seronegative spondylarthritis (SpA; black) are divided according to their expression of interferon (IFN)-γ, interleukin (IL)-2, and tumor necrosis factor (TNF)-α after stimulation with varicella zoster virus antigen (VZV, upper panel) or Staphylococcus aureus enterotoxin B (SEB, lower panel). To ensure robust statistics, this analysis was restricted to all VZV-positive samples where at least 30 cytokine-producing CD4 T cells were detectable (29 samples for HC, 27 for RA, and 10 for SpA, respectively). Bars represent subpopulations of single-, double-, or triple-cytokine-producing cells among all VZV- or SEB-reactive CD4 T cells, including means and SDs. b Expression of the cytotoxic T-lymphocyte antigen 4 (CTLA-4), the programmed death 1 molecule (PD-1), and CD127 was analyzed on reactive (CD69⁺/IFN-γ⁺) CD4 T cells of HC, RA, and SpA. Only samples with at least 20 VZV-specific CD4 T cells were analyzed (n = 29 HC, 37 RA, and 10 SpA for CTLA-4; n = 14 HC, 17 RA, and 8 SpA for PD-1; and n = 15 HC, 37 RA, and 10 SpA for CD127). Statistical significance was assessed using one-way analysis of variance with Bonferroni posttest (a) or the Kruskal-Wallis test with Dunn’s posttest (b). Significant differences in posttests are marked by asterisks (*p < 0.05; **p < 0.01; ***p < 0.001)