Figure 3.

Double IHC staining in trachea and bronchus of pigs and llamas on day 4 p.i. (a) Trachea; pig. Extensive presence of DPP4 antigen (pink staining) in the cytoplasm and occasionally in cilia of pseudostratified epithelial cells, cytoplasm of macrophage like‐cells (arrows), neutrophils (arrowhead) and endothelial walls (curved arrow) in the trachea. (b) Bronchus; pig. Pseudostratified columnar epithelial cells, macrophage‐like cells (arrows), lymphocytes (arrowheads) and endothelial cells (curved arrows) show DPP4 antigen (pink staining) mainly in the cytoplasm and occasionally in cilia of respiratory epithelial cells. (c) Trachea; llama. DPP4 antigen (pink staining) is mainly located in the cilia and capillaries (arrows). (d) Bronchus; llama. DPP4 antigen (pink staining) was exclusively observed in the lining cilia. No MERS‐CoV antigen (brown) was detected in any of these tissues (a)‐(d). Original magnification: ×400 for all tissues [Colour figure can be viewed at http://wileyonlinelibrary.com]