An international group of biologists may have found a gene that explains why the brain is protected from the herpes virus.
The World Health Organization says around 67 per cent of the world’s population is infected with the herpes simplex virus (HSV) type 1.
It mainly attacks nerve tissue, but in rare cases can reach the central nervous system and cause death.
Most carriers do not show severe symptoms, however, and the study – led by Cai Yujia, from Shanghai Jiao Tong University and Søren Paludan from Aarhus University in Denmark – tried to find out why.
Using the gene-editing tool CRISPR, they found that a gene known as “TMEFF1” was the key.
The team found that knocking out the gene in human stem cell-derived neurons could lead to a significant increase in HSV-1 replication.
The finding was confirmed by tests on mice. The viral load in the neurons in the animals’ brains significantly increased when the gene was knocked out.
The findings were published in the peer-reviewed journal Nature on July 24.
Although most HSV infections are asymptomatic or unrecognised, the virus still poses a global public health threat. Medicines can reduce symptoms but cannot cure the infection, according to the World Health Organization.
Recurrent symptoms of both oral and genital herpes are distressing for many infected people, but in rare cases the virus can attack the central nervous system with a disease called “herpes simplex encephalitis” that has a mortality rate of up to 70 per cent.
However, the researchers hope the discovery could help provide treatment for the condition and have developed peptides – smaller versions of the TMEFF1 protein – which they say are highly effective in preventing HSV infection.
“This study reports for the first time an antiviral factor that is exclusive to neurons, providing a completely new perspective for the study of the brain’s antiviral immune mechanism,” Shanghai Jiao Tong University said.
Zhao Guoping, a member of the Chinese Academy of Sciences and director of the Key Laboratory of Synthetic Biology, said in the Shanghai Jiao Tong University press release: “The discovery enriches our knowledge of the brain’s antiviral mechanisms and provides a new scientific basis for the future development of preventive and therapeutic treatments against HSV.”
