Immunity Cells and Our Eyes

Are immune cells doing much more than we think at protecting our eyes? There are so many things our eyes need protection from! Think of all the times you have gotten dust, sand, debris or even eyelashes in your eyes! Virus’ and bacteria notwithstanding, think of the chemical we use or come into contact with everyday, computers, smart phones and other devises! Then there’s the sun too! Well, it may be surprising to know that the main parts of the eyes, like the cornea, the lens and the retina are immune privileged! That means they lack immune cells and the protection they offer! So how do these important eye tissues protect themselves? Now in a new study published in The FASEB Journal on Dec 7^th, 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.Lets take a closer look at immunity cells and our eyes!

Who?

A few years ago, Sue Menko, PhD, professor of Pathology, Anatomy and Cell Biology at Thomas Jefferson University and researchers in her lab were studying a mouse that was engineered to lack a key protein required for the perfectly clear structure of the lens. As they expected, without this protein, the lens was malformed. But to their surprise, they also observed immune cells in the lens trying to fix the damage. This was the first time immune cells had been found to be recruited to the lens, and it challenged decades of scientific dogma. Building on their evidence, last year the Menko lab, in a collaboration with Mary Ann Stepp’s lab at George Washington University, found that when the cornea was wounded, immune cells traveled to the surface of the lens to protect from further damage.

What?

Immune cells are well-equipped to get to places where there might be damage or infection, secreting enzymes that break down tissues that are in the way. But are they able to get past the thick lens capsule? In a surprising finding, the researchers found that some immune cells were able to do so and actually infiltrate into the lens tissue.

How?

Their collaborators in Dr. Stepp’s lab confirmed this by using a scanning electron microscope, which can capture detailed changes on the surface of the lens capsule. They found many bumps, indicating regions where immune cells had become integrated within the lens capsule. This correlated with the fluorescent labeling results from the Menko lab.

Why this matters?

“Till now, the mechanisms for damage that happen in this region of the eye after uveitis have been poorly understood,” says Dr. Menko. “For the first time, we’ve been able to provide evidence that immune cells could be driving this damage, particularly to the lens.”

The study opens up possibilities of understanding lens pathology in other eye diseases like glaucoma.