FIG 5.

Mixed lymphocyte reaction (MLR) between allogeneic T lymphocytes and DCs pretreated with SiO₂ NPs and bacterial EMs. Allogeneic T cells, prelabeled with CFSE, were incubated for 5 days with DCs that had been preincubated with the indicated doses of SiO₂ NPs and EMs for 24 h and washed before the assay. The percentages of proliferating T cells, identified on the basis of their reduced MFI by FACS, are the means ± SEs (n = 7, run in triplicate); the concentration of LPS, which was used as a positive control, was 100 ng/ml. Black asterisks, P < 0.05 with respect to cells treated with NPs alone for all EM concentrations used; green or red asterisks, P < 0.05 with respect to cells treated with NPs alone for the indicated concentration of EMs (indicated by the green and red symbols, respectively). Orange straight lines, IC₅₀ values.