Compartmentalized ocular lymphatic system mediates eye-brain immunity.

Area of Science:

• Neuroimmunology
• Ophthalmology
• Lymphatic Biology

Background:

• The eye shares molecular and cellular similarities with the brain, suggesting potential immune connections.
• The immunological relationship between the posterior eye and central nervous system (CNS) tissues is largely unexplored.

Purpose of the Study:

• To investigate the immunological link between the posterior eye and the CNS.
• To explore the therapeutic potential of targeting ocular lymphatic drainage for CNS diseases.

Main Methods:

• Studied immune responses to herpes simplex virus in mice.
• Utilized intravitreal immunization and intracranial viral challenge models.
• Investigated lymphatic drainage pathways of the anterior and posterior eye compartments.
• Examined the role of Vascular Endothelial Growth Factor C (VEGFC) in lymphatic signaling.
• Assessed the impact of inhibiting lymphatic signaling on gene therapy efficacy using adeno-associated virus (AAV).

Main Results:

• Intravitreal immunization conferred protection against intracranial viral, bacterial, and glioblastoma challenges.
• The posterior eye compartment drains to deep cervical lymph nodes via lymphatic vasculature in the optic nerve sheath.
• Posterior lymphatic drainage is modulated by VEGFC, similar to meningeal lymphatics.
• Inhibiting optic nerve lymphatic signaling reduced immune responses to AAV, improving gene therapy efficacy.

Conclusions:

• A shared lymphatic circuit facilitates unified immune responses between the posterior eye and the brain.
• The eye possesses an understudied immunological feature with potential for novel therapeutic strategies in ocular and CNS diseases.