Protecting sight with F4/80

On page 1615, Lin and colleagues show that an adhesive glycoprotein is essential to prevent the immune system from reacting to environmental antigens encountered by the eyes. The authors show that this glycoprotein, known as F4/80, induces CD8⁺ regulatory T (T reg) cells thus protecting the eye and perhaps other immune-privileged sites from immune attack.

The F4/80 glycoprotein was first described over two decades ago and has since served as a sensitive marker of resident tissue macrophages. However, this protein had no identified function or ligand. Previous studies by this group showed that F4/80⁺ antigen presenting cells (APCs) carry antigens from the eye to the spleen. Once there, the APCs induce the development of CD8⁺ T reg cells, which...