Herpes simplex virus type I can cause bouts of cold sores, blindness and potentially lethal encephalitis when it reawakens from a quiescent state in the nerve cells it infects.
To prevent these consequences, the stealthy virus is kept under constant guard by the immune system, say University of Pittsburgh scientists. Their research challenges the once common notion that latent HSV-1 in sensory neurons is invisible to the immune system.
Actually, immune cells keep the infection under close surveillance, actively holding HSV-1 in check without destroying the neurons harboring it, said Robert L. Hendricks, Ph.D., Joseph F. Novak professor and vice-chair for research in the Department of Ophthalmology and professor in the Departments of Immunology and Microbiology and Molecular Genetics at the University of Pittsburgh School of Medicine. Sensory neurons may not regenerate, so an immune system attack that destroys them could do more harm than good.
In a paper published in the October 10 issue of Science, teams led by Dr. Hendricks and Paul R. Kinchington, Ph.D., also a professor in the University of Pittsburgh School of Medicine Department of Ophthalmology, show one way this balancing act is carried out.