Fig 4.

M. leprae enters human primary nasal epithelial cells. (A) Primary nasal epithelial cells were isolated from nasal polyps, and culture purity was determined by immunostaining with anti-cytokeratin-19 (CK-19) (red). Cell nuclei were labeled with DAPI (blue). (B) Isotype control. (C and D) Cells were infected with prelabeled PKH67 gamma-irradiated M. leprae at an MOI of 10 at 37°C for 2 h. (C) Representative confocal image of 4 independent experiments showing nasal primary cells infected with M. leprae (green; arrow). (D) The numbers of bacteria that interact with, adhere to, and enter primary nasal epithelial cells were determined. Data represent the means ± standard deviations of the results of 4 experiments performed in duplicate.