Herpes simplex virus genes controlling reactivation from latency in rabbit eye model

Area of Science:

• Virology
• Ophthalmology
• Infectious Diseases

Background:

• Herpes simplex virus (HSV) establishes lifelong latent infections in neurons.
• Reactivation of latent HSV can lead to recurrent disease, particularly in the eye.
• HSV type 1 (HSV-1) and HSV type 2 (HSV-2) exhibit different clinical manifestations and reactivation patterns.

Purpose of the Study:

• To investigate the genetic basis for differential reactivation between HSV-1 and HSV-2 in a rabbit eye model.
• To identify specific viral genes responsible for the distinct reactivation frequencies observed between HSV-1 and HSV-2.

Main Methods:

• Utilized a rabbit eye model to study HSV latency and reactivation.
• Induced reactivation using epinephrine iontophoresis.
• Generated intertypic recombinants by cotransfecting HSV-1 (McKrae) and HSV-2 (HG52) DNA.
• Analyzed recombinants for reactivation frequency and mapped genetic inserts.

Main Results:

• HSV-1 strain McKrae consistently reactivated, while HSV-2 strain HG52 failed to reactivate under identical conditions.
• Both HSV-1 and HSV-2 established latent infections with similar efficiency.
• Recombinants containing HSV-2 genetic material within specific map units (0.35-0.56 and/or 0.82-1.0) did not alter the reactivation frequency compared to HSV-1.

Conclusions:

• The genetic regions analyzed in HSV-2 do not determine the differential reactivation observed between HSV-1 and HSV-2 in the rabbit eye model.
• Further research is needed to pinpoint the specific viral genes controlling HSV reactivation.