Fig. 8.

CD83^-/low STM-D23580-infected MoDCs direct defective activation of Salmonella-specific CD4⁺ T cells. At 6 h p.i., a STM-LT2-infected MoDCs were sorted as CD83⁺ while b STM-D23580-infected MoDCs were sorted as CD83^-/low or CD83^high. c Uninfected MoDCs were used as negative control. Sorted subsets of infected MoDCs were co-cultured overnight with PhoN-specific CD4⁺ T cell clones cross-reactive against typhoidal and non-typhoidal serovars. d Capacity of CD4⁺ T cell to secrete IFN‐γ and TNF-α, as detected by intracellular staining. FACS plots show the percentage of IFN‐γ⁺/TNF-α⁺ cells out of total CD3⁺ CD4⁺ T cells. Dot plots comprise a representative experiment out of four. e CD83^−/low STM-D23580-infected MoDCs induce a significantly lower amount of cytokine-producing T cells, as compared to CD83^high STM-D23580 or CD83⁺ STM-LT2 infected cells. The mean±SEM of three independent experiments is shown One-way ANOVA test, P-value < 0.05 (*). f Flow cytometry histogram showing CD40L expression on T cells co-cultured with CD83⁺ STM-LT2 infected MoDCs, CD83^−/low or CD83^high STM-D23580-infected cells. Histograms from one representative example of at least three biological replicates. g Geometric mean of fluorescence intensity for CD40L in T cells co-cultured with CD83^−/low STM-D23580-infected MoDCs, represented as a percentage of reduction from CD83^high STM-D23580-infected MoDCs. three independent experiments are shown. Two-tailed paired Student’s t-test, P-value < 0.05 (*)