In silico modeling of DPP4-S protein binding, showed a similar
binding energy between human and marmoset DPP4 with
spike, whereas modeling ferret DPP4 with S protein results in a
higher binding energy, indicative of decreased or a lack of binding.
Subsequently, nine male common marmosets aged 2–6 years were
inoculated with 5.2 106 TCID50 HCoV-EMC/2012 using a combination
of routes (IT, IN, oral, and ocular). In contrast to rhesus
macaques, they developed moderate to severe signs of respiratory
disease, including increased respiratory rate up to >150 respiratory
rates per minute, open mouth breathing, loss of appetite, decreased
levels of activity, failure to move upon prompting, and the presence of oral frothy hemorrhagic discharge. A transient
decrease in body temperature was noted. On 4 dpi, two animals
were euthanized due to severity of disease based on clinical symptoms.
The remaining animals were euthanized on 3, 6 dpi, or monitored
for survival. Radiographic imaging showed mild to severe
bilateral interstitial infiltration, in cases combined with partial or
full congestion of the bronchioles.