MOLECULAR-BIOLOGY OF HERPES-SIMPLEX VIRUS TYPE-1 LATENCY IN THE NERVOUS-SYSTEM

Herpes simplex virus (HSV) is one of the best studied examples of vira l ability to remain latent in the human nervous system and to cause re current disease by reactivation. Intensive effort was directed in rece nt years to unveil the molecular viral mechanisms and the virus-host i nteractions associated with latent HSV infection. The discovery of the state of the latent viral DNA in nervous tissues and of the presence of latency-associated gene expression during latent infection, both di ffering from the situation during viral replication, provided importan t clues relevant to the pathogenesis of latent HSV infection. This rev iew summarizes the current state of knowledge on the site of latent in fection, the molecular phenomena of latency, and the mechanisms of the various stages of latency: acute infection, establishment and mainten ance of latency, and reactivation. This information paved the way to r ecent trials aiming to use herpes viruses as vectors to deliver genes into the nervous system, an issue that is also addressed in this revie w.