Fig. 8.
CSE suppresses IFN-β induction by influenza virus in epithelial cells in the human lung. Lung slices were exposed to 6 × 106 PFU/ml of influenza virus PR8 or virus diluents for 24 h in the presence of BFA to enhance the detection of cytokines. Slices were then processed for immunohistochemistry for the detection of IFN-β using goat polyclonal antibodies, viral NP using rabbit polyclonal antibody, and epithelial cells using anti-cytokeratin monoclonal antibody. Top: PR8 alone. Bottom: CSE + PR8. A–D: fluorescent images that demonstrate nuclei (A; blue), NP (B; red), IFN-β (C; green), and epithelial cells (D; cyan). E: bright-field images. F: overlays of the fluorescent images that demonstrate that the primary cellular sources of the cytokines are epithelial cells (arrows). Bars = 100 μm.