Sohn J H, Kaplan H J, Suk H J, Bora P S, Bora N S
Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA.
Invest Ophthalmol Vis Sci. 2000 Oct;41(11):3492-502.
To explore the role of the complement system and complement regulatory proteins in an immune-privileged organ, the eye.
Eyes of normal Lewis rats were analyzed for the expression of complement regulatory proteins, membrane cofactor protein (MCP), decay-acceleration factor (DAF), membrane inhibitor of reactive lysis (MIRL, CD59), and cell surface regulator of complement (Crry), using immunohistochemistry, Western blot analysis, and reverse transcription-polymerase chain reaction (RT-PCR). Zymosan, a known activator of the alternative pathway of complement system was injected into the anterior chamber of the eye of Lewis rats. Animals were also injected intracamerally with 5 microl (25 microg) of neutralizing monoclonal antibody (mAb) against rat Crry (5I2) or CD59 (6D1) in an attempt to develop antibody induced anterior uveitis; control animals received 5 microl of sterile phosphate-buffered saline (PBS), OX-18 (25 microg), G-16-510E3 (25 microg), or MOPC-21 (25 microg). The role of complement system in antibody-induced uveitis was explored by intraperitoneal injection of 35 U cobra venom factor (CVF), 24 hours before antibody injection. Immunohistochemical staining and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with Western blot analysis were used to detect the presence of membrane attack complex (MAC) and C3 activation products, respectively, in normal and antibody-injected rat eyes.
Complement activation product MAC was present in the normal rat eye, and intraocular injection of zymosan induced severe anterior uveitis. The complement regulatory proteins, MCP, DAF, CD59, and Crry, were identified in the normal rat eye. Soluble forms of Crry and CD59 were also detected in normal rat aqueous humor. Severe anterior uveitis developed in Lewis rats injected with a neutralizing mAb against Crry, with increased formation of C3 split products. Systemic complement depletion by CVF prevented the induction of anterior uveitis by anti-Crry mAb. Intracameral injection of anti-rat CD59 (6D1), anti-rat MHC class I antigen (OX-18), anti-rat Ig (G-16-510E3), or MOPC-21 caused no inflammatory reaction.
The results suggest that the complement system is continuously active at a low level in the normal eye and is tightly regulated by intraocular complement regulatory proteins.
探讨补体系统及补体调节蛋白在免疫赦免器官——眼中的作用。
运用免疫组织化学、蛋白质印迹分析及逆转录-聚合酶链反应（RT-PCR），分析正常Lewis大鼠眼中补体调节蛋白膜辅助蛋白（MCP）、衰变加速因子（DAF）、反应性溶解膜抑制因子（MIRL，CD59）及补体细胞表面调节因子（Crry）的表达情况。将已知的补体系统替代途径激活剂酵母聚糖注入Lewis大鼠眼前房。动物还被前房内注射5微升（25微克）抗大鼠Crry（5I2）或CD59（6D1）的中和单克隆抗体（mAb），试图引发抗体诱导的前葡萄膜炎；对照动物接受5微升无菌磷酸盐缓冲盐水（PBS）、OX-18（25微克）、G-16-510E3（25微克）或MOPC-21（25微克）。在注射抗体前24小时腹腔注射35单位眼镜蛇毒因子（CVF），以探讨补体系统在抗体诱导的葡萄膜炎中的作用。分别采用免疫组织化学染色及十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）结合蛋白质印迹分析，检测正常及注射抗体大鼠眼中膜攻击复合物（MAC）及C3激活产物的存在情况。
正常大鼠眼中存在补体激活产物MAC，眼内注射酵母聚糖可诱发严重的前葡萄膜炎。在正常大鼠眼中鉴定出补体调节蛋白MCP、DAF、CD59及Crry。在正常大鼠房水中也检测到可溶性形式的Crry和CD59。注射抗Crry中和mAb的Lewis大鼠发生严重的前葡萄膜炎，C3裂解产物形成增加。CVF导致的全身补体耗竭可预防抗Crry mAb诱导的前葡萄膜炎。前房内注射抗大鼠CD59（6D1）、抗大鼠MHC I类抗原（OX-18）、抗大鼠Ig（G-16-510E3）或MOPC-21未引起炎症反应。
结果表明，补体系统在正常眼中持续处于低水平激活状态，并受到眼内补体调节蛋白的严格调控。
