EHV-1 gene63 is not essential for in vivo replication in horses and mice, nor does it affect reactivation in the horse: short communication.

This research focused on understanding the function of gene63 in the equine herpesvirus 1 (EHV-1). The study found that mutation of gene63 did not appear to influence EHV-1’s ability to replicate and reactivate in horses and mice.

Objective of the Study

• This research aimed to examine the role of the immediate early gene (gene63) in the development and reactivation of acute and latent infections of equine herpesvirus 1 (EHV-1) in horse and mouse models.

Methodology

• The researchers used EHV-1 gene63 mutant virus (g63mut) and EHV-1 (Ab4) in this study.
• Both these viruses were used for intracerebral and intranasal infection in mice who were 3 and 17 days old.
• Two Welsh ponies were intranasally infected with each virus to monitor acute infection.
• Virus isolation from nasal swabs and peripheral blood leukocytes was done for monitoring purposes.

Observations

• Following the infection, both viruses were recovered at the same frequency from tissues.
• At six weeks post-infection, peripheral blood leukocytes obtained from the ponies showed positive in vitro reactivation for both viruses.
• Both viruses were isolated from bronchial and submandibular lymph nodes during autopsy.

Conclusion

• The researchers concluded that the mutation of EHV-1 gene63 does not seem to influence the virus’s ability to establish and reactivate from its latent state, suggesting that this gene does not play a critical role in the virus’s pathogenesis and reactivation.