Figure 4.

Inhibition of AYn1 and AYp28 peptides on pseudovirus invasion in hACE2 mice. (a) Schematic illustration of experimental procedure. Pseudovirus containing luciferase reporter gene was intranasally (i.n.) administered to hACE2 mice 3 hours after peptides treatment (500 μg/kg, 5 μL). After pseudovirus exposure, animals were intraperitoneally (i.p) injected with Luciferin (200 μL) and subjected to imaging at day 2, 5 and 10. After final imaging observation, all animals were sacrificed for IHC staining and RT-PCR. (b) The dynamic changes of pseudovirus invasion in mice were observed by using IVIS Lumina III system. The luciferin luminance can be ameliorated by AYp28, AYn1 or AYn1/AYp28 treatment. (c) Ten days post pseudovirus exposure (Pvirus exp), the pseudovirus content in lungs was quantified by using RT-PCR, as indicated by the 119 bp S-protein band. Pseudovirus can be detected in PBS-treated group, which can be diminished by treatment with AYp28 or AYp28/AYn1. AYn1 treatment alone showed a relative weak therapeutic effect. (d) Pseudovirus locations in lungs 10 days after pseudovirus exposure were further confirmed by IHC staining using anti-luciferease antibody. Consistent with the data of RT-PCR, clearly positive staining can be observed, which can be significantly ameliorated by pre-treatment with AYp28, AYn1 or AYp28/AYn1 combination.