Reactivation of herpes simplex virus (type 2) infection in trigeminal ganglia and oral lips with cyclophosphamide treatment.

Age-dependent resistance in trigeminal nerve against type 2 herpes simplex virus infection through oral lips and reactivation of the latent virus infection with cyclophosphamide in the ganglion in correlation to theprimary infected part were studied in mice with immunofluorescent and histopathological methods. The mice acquired resistance in the nervous tissue after 8 weeks of age. The viral antigen appeared in all trigeminal ganglia immediately after infection, but not found at 4 weeks later. Reactivation of the latent infection was tried by using 8-week-old mice with cyclophosphamide treatment. Four to five times administration of the drug produced the leasions of herpes simplex virus infection in the ganglia and also in the primary infected areas, but viral antigen-bearing neurons in the ganglia were very few.