Full title:A Coxsackievirus B1-infected neonatal rhesus macaques HFMD
model and viral tissue tropism
Abstract
Coxsackie virus B1 (CVB1) is an enterovirus that presents as hand, foot
and mouth disease (HFMD), which may cause long-term symptoms in some
patients. However, CVB1 animal models, detoxification cycles, and
long-term tissue tropism have not been systematically characterized. In
this study, a CVB1 respiratory infection model was established in rhesus
macaques, and clinical symptoms, viral load, and immune marker levels
were observed in the acute phase (0-14 days) and long-term recovery
phase (15-30 days). We also quantified the distribution, replication,
and pathology of CVB1 during the long-term recovery period using 35
postmortem rhesus macaques tissue samples at 30 days post infection
(d.p.i), thus revealing the long-term tissue tropism of the virus. The
results showed that the respiratory tract of rhesus macaques was
susceptible to CVB1 and showed HFMD symptoms, detoxification phenomena,
changes in cytokine levels, and neutralizing antibodies. Autopsy viral
load results were positive in heart, spleen, pancreas, pharyngeal flat,
and olfactory bulb tissues, and HE staining revealed pathological damage
to the liver, spleen, lung, pharyngeal flat, palatal flat, and tracheal
epithelium. Viral antigens were present in visceral, immune,
respiratory, and muscle tissues but not detected in intestinal and
neural tissues. Brain tissue was dissected and showed viral
meningitis-like changes, and CVB1 antigen expression was observed in
occipital, pontine, cerebellar, and spinal cord tissues. This study
first provides a basis for elucidating CVB1 pathogenesis in a nonhuman
primate HFMD model and then confirms the CVB1 tissue tropism pattern
after long-term infection.