Immune Cells Challenge Scientific Dogma
How often does shampoo get in your eyes when you take a shower? Your eyes encounter foreign materials on a daily basis: dust, bluelight, UV radiation from sunlight, and even chemicals from hygiene products. With your eyes being the only means of having the ability to see, how are they able to keep themselves safe? In December 2021, PhD professor, Sue Menko, conducted a study investigating the role that immune cells play in keeping the eyes well-protected and in pristine condition.
The roots of Menko’s exploration originated in her interest in the lens, which she intensely experimented on with a previous study on mice. In this past study, mice were engineered to lack an essential protein to the eye. Her conclusions were correct, such that without that key protein, the lenses of the mice did not develop correctly. However, an unexpected result also occurred: for the first time, immune cells attempted to salvage what was left of the lens. This challenges decades of ophthalmology, because many parts of the eye, such as the lens, are said to be immune-privileged. This suggests that they do not require the help of the immune system to repair any damages to the eye. Moreover, while the damage was located at the lens, immune cells were seen in other areas like the cornea.
With this in mind, Menko wanted to see if the effect of uveitis on the lens will summon immune cells, as it is a form of eye inflammation triggered by infection: "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." Additionally, as researchers continued to investigate the lens, they also observed immune cells present in the lens capsule, a thick protein-rich layer that was always thought to protect the lens. While this may seem beneficial to the eye, immune cells secrete enzymes that break down tissues. Their ability to get past a thick layer like the lens capsule indicates that they can be harmful to the eye.
As of now, it is evident that damage to immune-privileged regions of the eye are yet to be properly understood, but Menko’s work demonstrates that immune cells could possibly be what are furthering the damage in the eye, especially in the lens. The fate of the immune cells is inconclusive, but Dr. Menko hopes to further expand her studies by using her work to investigate lens pathology and other eye diseases like glaucoma.