Stress hormones epinephrine and corticosterone modulate herpes simplex virus 1 and 2 productive infection and reactivation primarily in sympathetic, not sensory, neurons

Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) infect and establish latency in peripheral neurons, from which they can reactivate to cause recurrent disease throughout the life of the host. Stress is associated with exacerbation of clinical symptoms and induction of recurrences in humans and animal models. The viruses preferentially replicate and establish latency in different subtypes of sensory neurons, as well as in neurons of the autonomic nervous system that are highly responsive to stress hormones. To determine if stress-related hormones modulate productive and latent HSV-1 and HSV-2 infection within sensory and autonomic neurons, we analyzed viral DNA after treatment of primary adult murine neuronal cultures with the stress hormones epinephrine and corticosterone. Both sensory trigeminal (TG) and sympathetic superior cervical ganglia (SCG) neurons expressed adrenergic receptors and glucocorticoid receptor. In productively infected neuronal cultures, epinephrine treatment significantly increased HSV-1 DNA replication and production of viral progeny in SCG neurons, but no significant differences were found in TG neurons. In contrast, corticosterone significantly decreased HSV-2 DNA replication and production of viral progeny in SCG neurons, but not in TG neurons. In quiescently infected neuronal cultures, epinephrine and corticosterone significantly increased HSV-1 reactivation from sympathetic SCG neurons, but not sensory TG neurons. In contrast, corticosterone increased HSV-2 reactivation from both SCG and TG neurons, but epinephrine had no effect. Adrenergic or epinephrine-induced reactivation of HSV-1 in SCG neurons involved activation of several adrenergic receptors, the cyclic AMP response element binding protein (CREB), the transcription factor β-catenin, and the c-Jun N-terminal kinase (JNK). Corticosterone-induced reactivation of HSV-1 in SCG neurons required activation of glucocorticoid receptor (GCR) and transcription factors CREB and JNK. In contrast, corticosterone-induced reactivation of HSV-2 in TG and SCG neurons could utilize either the GCR or mineralocorticoid receptor (MCR) and most likely involves the chromatin remodeling properties of those receptors. Thus, stress-related hormones, epinephrine and corticosterone, selectively modulate productive and quiescent HSV-1 and HSV-2 infections primarily in sympathetic, but not sensory, neurons through different mechanisms. These results have implications for describing a mechanism by which stress-induced reactivation may occur in humans.