New research suggests the eye can host an active immune response. The finding, published in Nature, has implications for wound healing in the eye and changes in vision like cataracts.
The finding surprised Professor Sue Menko at Thomas Jefferson University. Dr. Menko was looking at a mouse engineered to stop producing a protein called N-cadherin as the lens was beginning to form. N-cadherin is critical for lens development because of its functions in cell-cell adherence and connectivity, cell migration, and the regulation of cytoskeletal organisation.
The study authors wrote, “Loss of this cell-cell junctional protein leads to lens degeneration, necrosis and fibrotic change, postnatally. The degeneration of this tissue induces an immune response resulting in immune cells populating the lens that contribute to the development of fibrosis.”
The researchers found, “the lens is connected to the lymphatic system, with LYVE(+) labelling reaching the lens along the suspensory ligaments that connect the lens to the ciliary body, providing a potential mechanism for the immune circulation. Importantly, we observe that degeneration of the lens activates an immune response throughout the eye, including cornea, vitreous humor, and retina, suggesting a coordinated protective response in the visual system to defects of a component tissue. These studies demonstrate that lens degeneration induces an immune response that can contribute to the fibrosis that often accompanies lens dysgenesis, a consideration for understanding organ system response to injury?