Zamiri Parisa, Sugita Sunao, Streilein J Wayne
Schepens Eye Research Institute, Harvard Medical School, Boston, Mass., USA.
Chem Immunol Allergy. 2007;92:86-93. doi: 10.1159/000099259.
The immune privilege of the anterior chamber of the eye has been recognized for over 100 years. However, the unique immunological properties of the pigmented epithelial (PE) cells of the eye and the subretinal space (SRS) have only recently been appreciated. The PE cells of the iris, ciliary body, and retina reside in anatomically disparate locations and serve distinctly different functions, yet share interesting immunomodulatory properties that contribute to ocular immune privilege. PE cells in the ciliary body and retina elaborate a variety of soluble factors that either directly or indirectly dampen immune-mediated inflammation; these include transforming growth factor-Beta, somatostatin, thrombospondin and pigment epithelial derived factor (PEDF). The constitutive expression of the immune co-stimulatory molecule, CD86, on iris PE cells not only inhibits T cell proliferation, but also promotes the generation of regulatory T cells. The SRS is now recognized as an immune-privileged site that shares many, but not all, of the properties ascribed to the anterior chamber, including the induction of systemic immune deviation. The prospect of therapeutic retinal transplantation and the possible immunologic etiology for some forms of age-related macular degeneration provides new impetus for gaining a better understanding of ocular immune privilege in the posterior regions of the eye.
眼睛前房的免疫赦免已被认识超过100年。然而，眼部色素上皮（PE）细胞和视网膜下间隙（SRS）独特的免疫学特性直到最近才被认识到。虹膜、睫状体和视网膜的PE细胞位于解剖学上不同的位置，发挥着截然不同的功能，但却具有有趣的免疫调节特性，这些特性有助于眼部的免疫赦免。睫状体和视网膜中的PE细胞会产生多种可溶性因子，这些因子直接或间接抑制免疫介导的炎症；其中包括转化生长因子-β、生长抑素、血小板反应蛋白和色素上皮衍生因子（PEDF）。虹膜PE细胞上免疫共刺激分子CD86的组成性表达不仅抑制T细胞增殖，还促进调节性T细胞的产生。SRS现在被认为是一个免疫赦免部位，它具有许多（但不是全部）归因于前房的特性，包括诱导全身免疫偏离。治疗性视网膜移植的前景以及某些形式的年龄相关性黄斑变性可能的免疫病因，为更好地理解眼后部区域的眼部免疫赦免提供了新的动力。
