a. CIP104441 NIZO2256 Human stool France CIP104440 NIZO1838 Human stool France NCIMB12120 NIZO1840 Cereal fermented (Ogi) Nigeria n.a. not available a See references [27, 28] for comparative genome hybridization analyses of these strains. Figure 1 Cytokine secretion by PBMCs after 24 h co-culture with L. plantarum strains. IL-10 (A) BI 6727 in vitro and IL-12 (B) production
and the IL-10/IL-12 ratio (C) by peripheral blood mononuclear cells (PBMCs) derived from blood of 3 different healthy donors after stimulation with 42 different L. plantarum strains harvested in stationary-phase. The L. plantarum strains grown and prepared on separate days constitute set 1 and set 2. PBMCs isolated from donor A were inoculated with L. plantarum culture set 1 (A-1) and PBMCs from donor B were inoculated with the L. plantarum replicate set 2 (B-2). PBMCs from Donor C received both sets of cultures and the mean of the IL-10 and IL-12 amounts induced by these cultures is shown. Each symbol represents a different
L. plantarum strain or the PBS or LPS controls. Identification of candidate genes involved in immunomodulation To identify candidate L. plantarum genes involved in
the modulation of the immune response, see more Random Forest models [38] were used to compare L. plantarum CGH profiles with the relative amounts of IL-10 and IL-12 and IL-10/IL-12 ratios induced by the strains in co-culture with PBMCs (Figure 1). PBMCs from different donors incubated with replicate L. plantarum cultures were used for these models to take into account Calpain the levels of variation in cytokine production. Comparisons of L. plantarum strain genotype to the IL-10-stimulating capacities resulted in the identification of 6 different chromosomal loci and a total of 13 genes that might influence IL-10 production (Table 2). In comparison, concise correlations between L. plantarum CGH profiles and IL-12 amounts were not found. One of the genes correlated with IL-10 amounts was L. plantarum WCFS1 lp_1953. L. plantarum strains harboring this gene stimulated the production of IL-10 in 1.6-fold higher amounts, on average, compared to L. plantarum strains for which this gene was absent.