HSV Latency In Vitro : In Situ Hybridization Methods.

Area of Science:

• Neurovirology
• Infectious Diseases

Background:

• Herpes simplex virus (HSV) establishes lifelong latent infections in neurons.
• Understanding the mechanisms of HSV latency is crucial for managing recurrent infections.
• Existing models provide insights but may not fully recapitulate human disease aspects.

Purpose of the Study:

• To develop and validate an in vitro model of HSV latency in primary neurons.
• To investigate the role of nerve growth factor (NGF) in maintaining HSV latency.
• To characterize the conditions for HSV latency establishment and reactivation in vitro.

Main Methods:

• Primary neuronal cultures from rodent and primate ganglia were used.
• HSV-1 and HSV-2 were inoculated into neuronal cultures.
• Antiviral agents (e.g., acyclovir) and varying multiplicities of infection (MOI) were employed.
• Nerve growth factor (NGF) was manipulated to study its effect on latency.

Main Results:

• The in vitro model successfully mimics key aspects of HSV latency observed in animal models and human disease.
• HSV-1 and HSV-2 establish latency in neuronal cell types consistent with human infections.
• Nerve growth factor (NGF) is indispensable for maintaining HSV latency; its depletion induces viral reactivation.
• Latency-associated transcripts (LAT) are the primary viral transcripts detected during the latent phase.

Conclusions:

• The developed in vitro model is a valuable tool for studying HSV latency.
• NGF plays a critical role in the maintenance of HSV latency.
• Deprivation of NGF is a potent trigger for the reactivation of latent HSV infections.