TRIF signaling deficiency abrogates the effect of hypertonicity on CD8+ T cell activation. (a) BMDCs of TRIFlps2/lps2 origin matured in isotonic or indicated NaCl-hypertonic conditions were used in OVA/OTI T cell activation assay as described (a, left). Alternatively, BMDCs matured in isotonic medium were stimulated with NaCl solely during OVA uptake (2 hours) and used in the same assay (a, right). (b–d) Cross-priming of OTI cells by BMDCs raised in different osmolarities, gained from MyD88−/−, TLR4−/− and TRIF−/− mice, respectively. Displayed graphs are representative of minimum two independent experiments (*p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001; n = 4). (e) BMDCs of TRIFlps2/lps2 origin matured in 290 mOsm (left column) and 450 mOsm (right column) media were used in PLA-assay as described. Negative control (right column) represents probes with application of only one antibody (25-D1.16.APC antibody was obeyed). The statistical data (f) demonstrate % of PLA-spot or –cluster positive cells within total PLA-positive BMDC population (displayed as mean ± SEM; representative of two pooled experiments, ***p ≤ 0.001, n = 21 high power fields).