There’s a lot that our eyes have to protect themselves from – dust and debris; viruses and bacteria; chemicals from things we use every day like soaps and lotions; ultraviolet radiation from the sun; and hours of looking at computer screens or devices. Given all these potential threats, it might be surprising to learn that parts of the eye that are central to vision – the lens, cornea and retina – are immune privileged, meaning they lack immune cells and the protection they offer. But then how do these critical tissues protect themselves?
Now in a new study, the researchers show that immune cells respond to the lens, not just following an acute injury in the eye, but also to long-lasting inflammation. In collaboration with Rachael Caspi’s lab at the National Eye Institute and the Mary Ann Stepp’s lab at George Washington University, the laboratory of Sue Menko, professor of Pathology, Anatomy and Cell Biology at Thomas Jefferson University, studied a mouse model of uveitis.
In their work published in The FASEB Journal, Dr. Menko and her lab used high-resolution microscopy to look at the whole eye and the surface of the lens. The first thing the researchers wanted to know was, do immune cells interact with the lens in this experimental model of uveitis?
“In our previous study in which the cornea was wounded, we saw a small number of immune cells on the surface of the lens, acting almost like sentinels,” says Dr. Menko. “In this case, it was like a battering ram. There were dozens of immune cells, and different types of them, including T-cells and macrophages. It’s clearly a robust immune response and could reflect in part that inflammation in uveitis is so severe.”
Immune cells line the edge of the lens capsule. Image credit: DeDreu, et al.