Comparison of the Immunomodulatory Properties of Three Probiotic Strains of Lactobacilli Using Complex Culture Systems: Prediction for In Vivo Efficacy
Figure 7
L. paracasei inhibits the ability of DCs to activate T cells.
Three situations were analyzed (a, b, c) as in fig. 6 DCs were incubated or not with the reported live bacterial strains either separately (SL, Salmonella; LP, L. paracasei) or together (LP+SL) for 1 h in medium without antibiotics, washed and incubated for 23 h in medium with antibiotics. a. Caco-2 cells were grown as monolayers in the upper chamber of a transwell filter. 24 h from achievement of a TER of 300 Ohm•cm2 supernatants (sn Caco) were collected from the bottom chamber and used to pre-treat DCs for 24 h before bacterial incubation as in a. b. Caco-2 cells were grown as monolayers in the upper chamber of a transwell filter and incubated with L. paracasei (5×107 CFU/TW) upon the apical surface (top chamber). One hour after incubation, bacteria were washed out and medium was changed with one containing antibiotics. Culture supernatants (sn caco LP) were collected 24 hours later from the bottom chamber, filtered and used to pre-treat DCs for 24 h before bacterial incubation as in a. Cells were then washed and incubated with naïve CD4+CD45RA+ cells for 5 days (Ratio 1∶10 DC∶T cells). Cell culture supernatants were collected and cytokines measured by ELISA or CBA Flex set. Error bars: standard deviations on values obtained on 3 different donors. *, p<0.05; **, p<0.01.