Broekhuyse R M, Kuhlmann E D, Winkens H J
Institute of Ophthalmology, University of Nijmegen, The Netherlands.
Exp Eye Res. 1992 Sep;55(3):401-11. doi: 10.1016/0014-4835(92)90112-6.
Retinal pigment epithelial cell fractions have been investigated for their capacity to induce experimental uveitis. Cells of the dark (melanotic) and light areas of the bovine RPE have subsequently been extracted by buffer, Triton X-100, sodium dodecyl sulfate (SDS), and treated with various reagents in order to study some characteristics of the antigen. The SDS-insoluble melanotic fraction, consisting of spindle-shaped, mature melanin granules, proved to be the most uveitogenic preparation. Using pertussis toxin as coadjuvant, 1 microgram of melanin-protein (3.4 x 10(6) granules) was able to induce experimental autoimmune anterior uveitis (EAAU) in Lewis rats. The pathogenic activity of the responsible pathogen (PEP-X) was not diminished by SDS, nor eliminated by mildly alkaline SDS or formic acid treatment. However, HCl-deproteinized granules were not uveitogenic. The results show that PEP-X is a highly stable melano-antigen that is probably covalently bound to the granule surface. This is the first time that a melanin-bound antigen has been demonstrated to evoke specific autoaggressive activity. EAAU could adoptively be transferred by sensitized and in vitro stimulated CD4 T-lymphocytes. The evoked inflammation started 3-4 days after injection, was similar to those induced by immunization, and consisted mainly of severe iridocyclitis accompanied by dense flare and cells in the anterior chamber. Choroiditis developed in severe cases of EAAU but no inflammation was detected in the retina, pineal gland or other organs of these rats. EAAU could not be transferred by serum. Immunized PVG rats and guinea-pigs did not develop ocular inflammation. In monkeys a high dose of antigen evoked a very mild EAAU accompanied by choroiditis. In view of its characteristics, EAAU may be a new model for human anterior uveitis.
视网膜色素上皮细胞组分诱导实验性葡萄膜炎的能力已得到研究。随后，用缓冲液、曲拉通X-100、十二烷基硫酸钠（SDS）从牛视网膜色素上皮的深色（含黑色素）和浅色区域提取细胞，并使用各种试剂进行处理，以研究抗原的一些特性。由纺锤形成熟黑色素颗粒组成的SDS不溶性含黑色素组分被证明是最具葡萄膜炎诱导性的制剂。以百日咳毒素作为佐剂，1微克黑色素蛋白（3.4×10⁶颗粒）能够在Lewis大鼠中诱导实验性自身免疫性前葡萄膜炎（EAAU）。致病病原体（PEP-X）的致病活性不会因SDS而降低，也不会因轻度碱性SDS或甲酸处理而消除。然而，经盐酸脱蛋白的颗粒没有葡萄膜炎诱导性。结果表明，PEP-X是一种高度稳定的黑色素抗原，可能与颗粒表面共价结合。这是首次证明与黑色素结合的抗原能引发特异性自身攻击活性。EAAU可通过致敏和体外刺激的CD4 T淋巴细胞进行过继转移。注射后3 - 4天引发炎症，与免疫诱导的炎症相似，主要表现为严重的虹膜睫状体炎，并伴有前房内浓密的闪光和细胞。在严重的EAAU病例中会出现脉络膜炎，但在这些大鼠的视网膜、松果体或其他器官中未检测到炎症。EAAU不能通过血清进行转移。免疫的PVG大鼠和豚鼠未发生眼部炎症。在猴子中，高剂量抗原引发了非常轻微的伴有脉络膜炎的EAAU。鉴于其特点，EAAU可能是人类前葡萄膜炎的一种新模型。
