Transplacental transfer and subsequent neonate utilization of herpes simplex virus-specific immunity are resilient to acute maternal stress.

Neonates are severely compromised in the ability to generate an immune response to pathogens and thus rely heavily on maternally derived immunity that is acquired by transplacental and transmammary means. The passive transfer of maternal herpes simplex virus (HSV)-specific antibody is critical in determining the outcome of neonatal HSV infection. In adults, psychological stress alters immune responsiveness via the increased level of corticosterone that is produced as a result of hypothalamic-pituitary-adrenal axis activation. Although the behavioral and neuroendocrine effects of pre- and postnatal stress-induced increases in corticosterone are well documented, the effects of maternal stress on the efficacy of prenatally transferred and neonatally developed viral immunity has yet to be addressed. By using a well-established prenatal restraint-and-light stress mouse model, we investigated the effects of increased maternal corticosterone on the passive transfer of total and HSV-specific immunoglobulin G (IgG) antibody and subsequent neonatal susceptibility to HSV infection. Serum corticosterone levels in pregnant mice were significantly increased in response to restraint-and-light stress, and fetuses derived from these stressed mice had significantly elevated levels of corticosterone. Despite the increases in corticosterone, the passive transfer of total and HSV-specific IgG antibody persisted and, in turn, protected the neonate from systemic viral spread. Therefore, prenatal stress did not increase the susceptibility of neonates to HSV type 2-associated mortality. These findings demonstrate the resiliency of the passive transfer of protective HSV-specific immunity under conditions of acute psychological stress.