Ocular immune privilege and retinal pigment epithelial cells

The ocular tissue microenvironment is immune-privileged and uses multiple immunosuppressive mechanisms to prevent the induction of inflammation. The retinal pigment epithelium plays an essential role in ocular immune privilege. In addition to serving as a blood barrier separating the fenestrated choriocapillaris from the retina, the retinal pigment epithelium is a source of immunosuppressive cytokines and membrane-bound negative regulators that modulate the activity of immune cells within the retina. This article reviews the current understanding of how retinal pigment epithelium cells mediate immune regulation, focusing on the changes under pathologic conditions. This review summarizes immune barrier roles of retinal pigment epithelium cell-derived tight junctions, immunosuppressive cytokines, and membrane-bound negative regulators and their role in modulating ocular immune privilege.

Automated summary

The retinal pigment epithelium is crucial for maintaining ocular immune privilege by using various mechanisms to suppress immune responses and prevent inflammation. This review focuses on the role of retinal pigment epithelium cells in immune regulation, particularly the changes that occur under pathological conditions.