Associations of the Adaptive Immune System and Age-Related Macular Degeneration

In recent years, the adaptive immune system has gained a significant amount of attention due to its potential role in age-related macular degeneration (AMD). Orthologous approaches including cellular and animal models as well as pilot clinical trials have paved the way to understand the occurrence, alterations, and interactions of T cell populations in the retina. Interestingly, the notions of the involvement of the adaptive immune system in AMD have also gained support through recent findings in various neurodegenerative and chronic low-grade diseases, including multiple sclerosis, Parkinson's disease, or arteriosclerosis. In this group of pathologies, cells of the adaptive immune system bypass immune barriers and fuel inflammatory processes at immune-privileged sites. These findings have pointed at immunosenescence as a critical pro-inflammatory process involving T cell biology. Using a murine model relevant to the pathophysiology of geographic atrophy, we have demonstrated that specific populations of memory T cells are recruited to the retina prior to neurodegeneration. The investigation of these retinas at later degenerative stages revealed the presence of activated cytotoxic T cells at the injury site. These compelling results support the participation of the adaptive immune system in retina degeneration and highlight the potential of T cell populations as an early therapeutic target to slow the progression of AMD.