Road to fulfilment: taming the immune response to restore vision.

While traditionally considered to be an immune privileged site, the eye, and in particular the retina, is nonetheless endowed with immune-competent cells capable of engaging powerful immune regulatory networks. By understanding the mechanisms that promote immune well-being in the eye, we are able to generate therapies which combat undue immune-mediated damage not only by revealing mechanisms that promote tissue damage, but also by an ability to restore tissue immune homeostasis by harnessing intrinsic immune-regulatory mechanisms. The result is to maintain or restore immune health as well as combat tissue damage evoked during, for example, intra-ocular inflammatory disease (uveitis), angiogenesis (age-related macular degeneration) and retinal degenerative disorders. Immune activation and regulation is a balance that is dictated by cognate and soluble factors at both a tissue and cellular level. These continuously respond to and eradicate danger and pathogenic signals whilst maintaining tissue function by controlling, and not exclusively, vascular barriers, complement activation, macrophage activation and keeping in check local T cell proliferation. Loss of the balance between activation and inhibitory signals leads to uncontrolled tissue damage. Understanding the mechanisms has gained potential therapeutic opportunities not only to suppress on-going inflammation, but also to restore homeostasis and prevent recrudescence.