(D) Invasion of wild-type pneumococci T4 (TIGR4) or its isogenic PLY mutant T4Δply into the lung epithelial models (n=3/condition) in the presence or absence of 100 μM peptide P2 or the control peptide CP2 at 2h post infection was measured using CFU viability assay following gentamicin killing of extracellular bacteria. Anti-PLY was used as control to test the effect of blocking PLY. Data in d and e are mean ± s.e.m. of n=3 models/condition from two independent experiments. % bacterial entry = (bacteria uptaken/input) x100. ** denotes P < 0.01 by one-way ANOVA with Dunnett's post hoc test for multiple comparisons. n.s. denotes not significant. Exact P values are shown in Appendix Table S4. 