Changes in the brain can be reflected in our eyes for it being the anatomical extension of the central nervous system (CNS). Given the proximity of eyes to the brain, a research team from Yale University decided to explore the possibility of immunological nexus between them. To understand protective immunity against viral challange in the brain, the team administered herpes simplex virus (HSV) vaccine through four different routes – intraperitoneal (IP), intracranial (IC), intracameral (anterior chamber [AC] and intravitreal [IVT]) and then induced infection in mouse model. Among the four routes, only IC and IVT immunizations protected the mice, unlike IP and AC routes. It suggested the utility of IVT immunization in generating protective immune response in the brain. The biggest finding of this study is the new biology of the posterior compartment of the eye has a unique lymphatic drainage system that anatomically engages with the CNS meningeal lymphatic network. The previously understudied immunological feature of the eyes has opened a window for development of novel therapeutic strategies in ocular and CNS diseases.

Reference:

Yin X, et al. Nature. 2024 Feb 28. doi: 10.1038/s41586-024-07130-8. Epub ahead of print.