Targets of infection in a herpes simplex-reactivation model

In mice surviving intracerebral inoculation with herpes simplex virus type 2 (HSV-2), recurrent infection was induced using high-dose immunosuppressive treatment. Targets of reactivated infection were identified in serial sections of heads using immunoperoxidase methods to detect viral antigen. Peripheral targets were cranial sensory and autonomic ganglia, peripheral nerves, and many non-neural structures. Central neural tissues included retina, optic nerve and tract, lateral geniculate nucleus and superior colliculus. Brain stem nuclei containing antigen were chiefly those associated with the trigeminal, facial, glossopharyngeal or vagus nerves. A few white matter regions were also positive. This is the first study using antigen methods to show that the central nervous system can be an important target of recurrent HSV infection in an animal model. Patterns of antigen-containing structures suggest that neural connections are important determinants of sites of reactivated infection. Decalcification of bone permits study of antigen distribution in tissues retaining their anatomical relationships.