The clinical impact of viral neuroinvasion on the central nervous system (CNS) ranges from barely detectable to deadly, including acute and chronic outcomes. Developing innovative therapeutic strategies is important to mitigate virusinduced neurological and psychiatric disorders. A key gatekeeper to the CNS is the neurovascular unit (NVU), a major obstacle to viral neuroinvasion and antiviral therapies. The NVU isolates the brain from the blood through firm sealing operated by the tight junctions (TJs) of endothelial cells. Here, we make the thoughtprovoking assumption that TJs can be targets to prevent or treat viral neuroinvasion and resulting disorders. This review aims at defining the conceptual diverse mode of actions of such approaches, evaluates their feasibility, and discusses future challenges in the field.
Tight junctions of the neurovascular unit: a ticket to the central nervous systemInfectious diseases that affect the central nervous system (CNS; see Glossary) are commonly observed in clinical practice [1]. Neurotropic viral infection can cause acute or chronic syndromes, including encephalitis, meningitis, meningoencephalomyelitis, Guillain-Barré-like-syndromes, or stroke. In the case of virus induced encephalitis, the incidence ranges from 1.5 to 7 cases/100 000 inhabitants/year, excluding epidemics [2]. This condition is severe, with high mortality rates, as exemplified by a Danish study estimating the cumulative mortality rate of patients with herpes simplex encephalitis at 18.6% [3]. In the United States for instance, encephalitis hospitalizations result in 5.6% mortality, among which infectious agents account for about 40% of deaths [4]. These studies highlight the importance of finding potent cures to fight neurotropic viral infections.