Figure 2.

HA314-46 peptide penetrates several different types of cells and mouse lung tissue. (a) Cell-penetrating activity of HA314-46 peptide in mouse primary cells. Splenocytes were freshly isolated from C57BL/6 N mice and were incubated with or without 10 μg/mL of FITC-conjugated peptides for 60 min at 37 °C. MFI of FITC in each cell population was analysed by flow cytometry. Data are presented as mean + SEM (n = 4). Asterisks show significant increase by one-way ANOVA with Bonferroni's multiple comparison test. **p < 0.01. (b) Peptide distribution in the lung tissue of mouse intranasal inhalation model. C57BL/6 N mice were intranasally exposed with 25 μg of FITC-conjugated peptides or saline (-). Lung frozen sections were stained with anti-fluorescein/Oregon Green polyclonal antibody and Alexa Fluor 555-conjugated secondary antibody for eliminating autofluorescence in the sections. The distribution of peptides was examined by confocal microscopy. Representative images from five experiments are shown. Red, peptide. Scale bar, 100 μm. Counterstaining of the serial section was done with H&E dyes.