WEDNESDAY, Feb. 17, 2021 (HealthDay News) – Scientists may have discovered why cold sores caused by herpes simplex virus (HSV) cause stress, illness, and burns.
The discovery could lead to new ways to prevent recurrent herpes inflammations and herpes-related eye diseases, say American and British researchers.
More than half of Americans are infected with the herpes simplex virus. It spreads by close contact with someone who has an infection and can reappear at any time.
“Now [that] the more we understand what can cause HSV to come out of hiding and reactivate, we can begin to understand how this works at the level of an infected nerve cell, ”said researcher Anna Cliffe, assistant professor of microbiology, immunology and cancer biology at the University of Virginia in Charlottesville.
“Our long-term goals are to understand how to ensure that herpes simplex cannot respond to these signals and therefore prevent reactivation,” she said.
Current anti-HSV therapies work to prevent the virus from replicating once it comes out of hiding. No therapy can yet target a latent infection, Cliffe explained.
“The herpes simplex virus hides in nerve cells for life, so once you have it, you always have it,” she said. “Sometimes it’s hidden, and it can cause a clinical illness, like herpes, eye disease and genital lesions.”
But scientists have not fully understood what can affect infected nerve cells and cause the virus to hide.
“In our study, we found that if neurons become more prone to fire impulses, then the virus can come out of hiding,” Cliffe said. Neurons are cells that transmit information to other cells of the nervous system.
A cytokine called interleukin 1 is released into the body when people become stressed or have a fever. It is also found in skin cells and can be released when exposed to ultraviolet light, including the sun. All of this can reactivate the herpes virus and cause cold sores on her lips, she explained.
“We also linked reactivation to the activation of a protein within a neuron called DLK,” Cliffe said.
Its activation is required for HSV to reactivate in response to interleukin 1, along with other triggers such as nerve cell damage, she said. This makes DLK a good target for HSV prevention, Cliffe added.
Repeated reactivation of HSV can also affect the eyes. In the eye the virus leads to herpes keratitis, it can result in blindness if left untreated. HSV infection is also associated with the progression of Alzheimer’s disease.
It is unclear whether these findings have implications for HSV treatment or prevention, Cliffe said. But this and future research could identify targets that could change the way the virus responds to stress.
In the future, these findings could lead to ways to prevent an outbreak, Cliffe said.
Brittany LeMonda, a senior neuropsychologist at Lenox Hill Hospital in New York City, reviewed the findings.
“The virus actually preys on our body’s natural immune response to stress,” she said.
The cytokine that the body releases in response to stress is the same one that can result in re-expression of HSV, LeMonda noted.
The way to prevent outbreaks is to reduce stress and follow a healthy lifestyle, she said.
“A healthy diet, adequate sleep, reducing anxiety and improving mental health are ways not only to reduce stress but also to prevent the recurrence of the disease,” LaMonda said.
The findings were recently published online in a journal eLife.
To learn more about herpes simplex, visit the American Academy of Dermatology.
SOURCES: Dr. Anna Cliffe, Assistant Professor, Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville; Brittany LeMonda, PhD, Senior Neuropsychologist, Lenox Hill Hospital, New York; eLife, online, 22 December 2020