Immune privilege ocular

D Orazio TJ, Mayhew E, Niederkorn JY Ocular immune privilege promoted by the presentation of peptide on toler-genic B cells in the spleen. II. Evidence for presentation by Qa-1. J Immunol 2001 166 26-32. 

Table 5.1. Factors responsible for ocular- immune privilege.

It is known that ACAID contributes to ocular tumor survival and long-term survival of orthoptic corneal allografts. Some experiments showed that removal of NKT cells prevented the continued acceptance of ocular tumors and caused the elimination of the immune privilege of the eye. Without functioning NKT cells, mice were not able to accept orthoptic corneal allografts for prolonged periods of time (Sonoda et al., 2002). This data demonstrates the essential role of NKT cells in the generation of ACAID. New information about ACAID may lead to application of ACAID mechanisms in prevention and treatment of immune-media ted inflammatory diseases in humans. 

Skelsey ME, Mellon J, Niederkom JY (2001) Gamma delta T cells are needed for ocular immune privilege and corneal graft survival. J Immunol 166 4327 333. 

For its protection, the retina is physiologically and immunologically segregated from the rest of the body by the blood retinal barrier formed by tight junctions between vascular endothelial cells and RPE cells. Only small molecules can cross this barrier, making it difficult for many drugs to reach ocular tissue. In addition, intraocular tissue is an immune privileged site. This protects the ocular tissue from the innocent bystander effect of inflammation. 

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