The cornea, the clear, protective outer layer of the eye, is crucial to helping people see, according to a groundbreaking new study from Australia's Peter Doherty Institute for Infection and Immunity. It produces a subtle and limited immune response that fights infection without damaging people's vision. The study, published in Cell Reports on the 24th, showed the presence of long-lived memory T cells in the cornea capable of "patroling" and fighting viral infection, subverting the current view that there are no T cells in a healthy cornea and expanding the eye's ability to An understanding of the immune response to infection.
Using a multiphoton microscope, the research team provided real-time images of living, intact biological tissue to study corneal cells from mice infected with herpes simplex virus. The images showed that long-lived memory T cells were generated in the eyes of mice to fight infection. After the virus is cleared, memory T cells remain in the cornea to prevent future reinfection.
Advanced imaging of healthy human eyes also revealed immune cells "patroling" the cornea, the first imaging of cells moving in a human eye.
Professor Scott Miller, head of the Doherty Institute laboratory and professor at the University of Melbourne, said: "The current understanding of the absence of T cells in healthy corneas needs to be reconsidered, as ours shows that tissue resident memory T cells (TRM cells) ) can enter the cornea and stay there for a long time.”
Professor Miller said the findings have important implications for understanding how the eye defends against dangerous infections and will improve understanding of how to protect the eye from infections such as the herpes simplex virus that can lead to permanent blindness. It also has implications for understanding chronic conditions such as dry eye disease and common eye allergies, where excess T cells can also contribute to disease.
