Fig. 3: Effects of Nicotinamide metabolites on pneumococcal replication.

A BEAS-2B lung epithelial cells were transfected with indicated siRNA for 48 h prior to infection with Spn D39, MOI 1 for 16 h. Bacterial replication was determined by CFU assay. B BEAS-2B cells were transfected as indicated for 48 h and the intracellular NAD content determined. C BEAS-2B cells were infected with Spn D39, MOI 1 for 16 h. Indicated amounts of NAD⁺ were added at the start of the infection. Bacterial replication was determined by CFU assays 16 h post-infection. D–F Spn D39 was cultivated in a host cell-free medium with indicated amounts of NAD⁺. CFU were determined at indicated time points. D Bacterial growth curves were measured over 21 h. The graph summarizes the mean of four biological independent replicates. E Maximally reached CFU/ml of (D). F Time (in h) until maximal CFU/ml was reached. Statistics: One-way ANOVA with Fisher’s LSD (A, B, E, F); Agonist vs Response-Fit (three parameters) (C); Error bars indicate SD (D); Significances were determined against scramble controls (A, B) or untreated controls (E, F); N = 7 biologically distinct samples (A); 4 biologically distinct samples (B–F); box plots: line at mean, box ranges from min to max; results are normalized against untreated controls (A, B).