MHV68 infected lung epithelial cells express epithelial and mesenchymal cell markers <i>in vivo</i>.

<p>(A) Immunofluorescent staining of frozen lung sections of MHV68 infected IFNγR−/− mice at day 7. Virus antigen detection was performed using an anti-MHV68 polyclonal antibody (green). Type II cells were detected using anti-pro-SP-C antibody (red). Sections were counterstained with DAPI (blue). Merged image shows yellow cells indicating type II cells that support lytic infection of the virus (arrows). Magnification ×800. Staining is representative of 5 different animals. (B) Immunostaining of frozen lung sections of IFNγR−/− mice at day 7 using a monoclonal antibody against the virus ORF59 (red) and the anti-FSP-1 antibody (green). Merged image shows nuclear localization of viral antigen in FSP-1 positive cells (arrows). Magnification ×400. Staining is representative of 3 different animals. (C) Dual IHC on formalin-fixed paraffin-embedded lung sections of MHV68 infected IFNγR−/− mice at day 120. Epithelial cells expressing mesenchymal cell markers (arrow) were detected using anti-TTF-1 (brown nuclei) and anti-FSP-1 (red cytoplasm) antibodies. Magnification ×400. Box shows area depicted with magnification ×1000. Staining is representative of 5 different animals. (D) Dual immunofluorescence staining in frozen lung sections of MHV68 infected IFNγR−/− mice at day 120 using anti-pro-SP-B (red) and anti-N-cadherin (green) antibodies. Yellow cells indicate type II cells expressing N-cadherin mesenchymal cell marker (arrows). Nuclei were visualized by DAPI staining (blue). Magnification ×200. Staining is representative of 5 different animals.