Fig. 2.

Enhanced cross-presentation upon RIG-I activation mediates efficient cross-priming of cytotoxic T cells in vitro. BMDCs were stimulated as described for Fig. 1 and were then cultured in the presence of OVA protein. (a) Cross-presentation of the processed peptide-epitope SIINFEKL in the context of MHC-I was analyzed by flow cytometry 18 h later. Data show H-2Kb-SIINFEKL expression on wild-type, IFNaR1- and MAVS-deficient cells. Data show mean fold change in comparison to untreated cells ± S.E.M. of quadruplicate samples pooled from two independent experiments. (b-d) Stimulated DCs were co-cultured with magnetically purified, CFSE-labeled CD8⁺ OT-I T cells in the presence of OVA protein. (b) CD8 T cell proliferation by CFSE dye dilution as well as IFN-γ levels in the supernatant from co-cultures with MAVS- (c) and IFNaR1-deficient DCs (d) were analyzed by flow cytometry or ELISA, respectively. (e-f) BMDCs from ASC-deficient animals were stimulated as described. (e) H-2Kb-SIINFEKL expression on DCs and (f) IFN-γ levels in the supernatant from co-cultures with CD8⁺ OT-I T cells were analyzed as described. All data give mean ± S.E.M. of at least triplicate samples representative of three independent experiments. (*P < 0.05, **P < 0.01, ***P < 0.001, one-way analysis of variance (ANOVA) for multiple comparisons). ns, not significant.