The work of researchers at Ohio State and Oxford Universities suggests the T-cells responsible for controlling a herpes virus can reduce significantly during times of new infection, allowing the latent virus to reactivate.
The mere mention of the word "herpes" usually conjures negative images and stereotypes, but most people have been infected with some form of the virus.
For most, a sore, pustules or rash appears, heals and is forgotten, although the virus remains latent just waiting for the right circumstances to come back (from shingles to cold sores). Intracellular reactivations of old herpes virus infections such as cytomegalovirus and Epstein-Barr are thought to trigger or contribute to the symptoms of a large percentage of fibromyalgia and ME/CFS patients.
Now, the mystery behind what triggers herpes viruses to become active again is closer to being solved thanks to a study reported in the November issue of Journal of Leukocyte Biology.
In the report, the researchers show how the immune system may lose its control over the virus when facing new microbial threats, such as when it must fend off other viral invaders or bacteria.
"Because almost all people are infected by one or more herpes family viruses during their lifetime, the potential impact of these findings is significant," says co-author Charles H. Cook, MD, director of surgical critical care at Ohio State College of Medicine. "We hope that by understanding how these latent viral infections are controlled we can prevent reactivation events and improve people's lives."
To make this discovery, the researchers studied mice with latent cytomegalovirus (CMV) during severe bacterial infections.
They found that:
• Memory T-cells responsible for CMV control were reduced significantly during a new infection with bacteria.
• This, in effect, reduced the "brakes" which kept the virus under control, allowing the virus to reactivate and cause disease. In humans, CMV reactivations typically cause ‘flu-like’ symptoms.
• When the immune system eventually sensed the reactivation, the memory T-cell levels returned to normal, effectively restoring the body's control over the virus.
"Finding ways to control herpes flare ups is important, not only for the health of the person with the virus, but also for preventing its transmission," comments John Wherry, PhD, Deputy Editor of the Journal of Leukocyte Biology.
The Importance of 'Microbial Interplay'
"This report highlights the important interplay when we are 'co-infected' with more than one microbe,” Dr. Wherry emphasizes, “and provides important insights into why the immune system sometimes fails, as well as how it can regain control of latent herpes virus infections."
Source: Based on Federation of American Societies for Experimental Biology news release, Oct 31, 2012