Fig. 6

IL-16 impaired the clearance of M. marinum in zebrafish larvae. A Timeline of animal vaccination, infection and killing. Zebrafish larvae were injected with morpholino (MO)-IL-16 (10 ng), MO-control (10 ng), MO-IL-16 (10 ng) plus human IL-16 mRNA (100 pg) at 0-0.5 h.p.f. Zebrafish infection with M. marinum was performed via caudal vein injection with 1.0 to 1.5 nl per fish of a single-cell bacterial suspension in PBS at a dosage of 5.0×107 CFU/mL at 30 h.p.f. B The relative level of IL-16 mRNA by qPCR in zebrafish larvae injected with morpholino oligos at indicated time (n = 12 to 20). C To assess the bacterial burdens, the homogenates of fish livers were plated onto 7H10 agar by serial dilution to determine CFU at 3 and 7 dpi (n = 8 to 36). D and F The overall reduction of infection level was determined by fluorescence microscopy. E and G Ziehl-Neelsen acid-fast staining was performed on 5 μm sections for gross pathology. H The survival of zebrafish during a 14-day infection. data represent means ± SEM. ∗p < 0.05, by 1-way ANOVA/Tukey’s multiple comparisons (B, C); A pool of 2 experiments is shown, including 15 to 22 zebrafish larvae per group as indicated, ∗∗p < 0.01 by log-rank test (H).