Fig 1: SteD interferes with CD97-dependent activation of T cells.(A) Quantification of CD69+CD4+ and CD69+CD8+ T cells in infected mice. Cells were isolated from draining MLNs of C57BL/6 mice inoculated orally with the indicated S. Typhimurium strains at indicated times post-inoculation. Amounts of CD69+ T cells are expressed as percentage of all CD11c-CD3+CD4+ or CD11c-CD3+CD8+ cells. Each dot represents the value obtained from MLNs pooled from two or three mice from three independent experiments and means ± SD are shown. * p < 0.05, ** p < 0.01, NS—not significant (two-way ANOVA followed by Tukey’s multiple comparison test). (B) Schematic of in vitro SIINFEKL (OVA)-dependent B3Z T cell activation assay. MutuDCs infected with GFP-expressing S. Typhimurium were exposed to SIINFEKL (ovalbumin-derived peptide for MHCI presentation). After 1 h, CD8+ B3Z T cells were added and co-incubated for 18 h prior to measurement of CD69 on B3Z T cells by flow cytometry. (C) In vitro SIINFEKL (OVA)-dependent B3Z T cell activation assay. WT, Cd97-/- or Cd97-/- + CD97-2HA MutuDCs were infected with WT-GFP or ?steD-GFP S. Typhimurium and exposed to SIINFEKL peptide. Percentage of CD69+ B3Z T cells in each condition is shown. Data are from 3 independent experiments and show means ± SD. * p < 0.05, *** p < 0.001, NS–not significant (two-way ANOVA followed by Tukey’s multiple comparison test).