The characteristics of hDPP4 transgenic mice subjected to aerosol MERS coronavirus infection via an animal nose-only exposure device

Hao, Xin-yan; Lv, Qi; Li, Feng-di; Xu, Yan-feng; Gao, Hong

Microscopically, challenged mice developed moderate acute interstitial pneumonia and brain pathology, but no pathological changes were detected in other tissues in the mice. In the aerosol group, the lungs of the exposed mice showed alveolar septal widening, inflammatory cell infiltration, and vessel dilatation and congestion at 3-9 days, gradual development of severe pathological changes and inflammatory cell infiltration in perivascular regions at 5-9 days, focal hemorrhages at 7-9 days, and an expanded pathology range at day 9 ( Figure 4B ). Dilatation and congestion of the cerebral vessels were not clearly observed until day 7, and few areas of neuron deformation necrosis were found in the cerebral cortex, hippocampus, and thalamus before day 9 ( Figure 3C ). On days 3 and 5 after intranasal infection, we found moderate acute interstitial pneumonia and brain lesions ( Figure 4B ,C). Tissue lesions, however, were milder in the aerosol group than in the instillation group. Furthermore, there were significant differences in the progression of lung and brain lesions in the two infected groups. Tissue lesion progression was slower in the aerosol-infected mice than in the instillation-infected mice ( Table 2 ).