UCL, Institute of Ophthalmology, London, UK.
Eye (Lond). 2009 Nov;23(11):2099-104. doi: 10.1038/eye.2008.372. Epub 2008 Dec 19.
Dendritic cells (DCs) express the high-affinity receptor for IgE (Fc(epsilon)RI) on their surface, which may enhance their ability to capture and internalize antigens for presentation to T-lymphocytes. The aim of this study was to determine if expression of Fc(epsilon)RI(+) DCs is increased in the conjunctivae of vernal keratoconjunctivitis (VKC) patients compared with those of normal controls.
Conjunctival biopsies were obtained from non-atopic and VKC patients. Double immunohistochemical staining was carried out using antibodies against Fc(epsilon)RI and the CD1a antigen, a DC marker. The double-positive cells were counted in five representative fields of view for each conjunctival sample.
Fc(epsilon)RI(+) CD1a(+) cells were present in significantly higher numbers in VKC conjunctivae compared with normal controls (mean cell count of 21.3 in VKC vs5.0 in controls, P<0.005). In normal patients the Fc(epsilon)RI-expressing DCs tended to be confined to the epithelial layer or the superficial substantia propria, but in the VKC samples these Fc(epsilon)RI(+) cells were mainly concentrated in the deeper substantia propria.
Fc(epsilon)RI(+) DC numbers are elevated in the conjunctivae of VKC patients, a finding consistent with the results of other studies focusing on atopic conditions. Elevated expression of Fc(epsilon)RI on DCs would facilitate antigen presentation and enhance T-cell priming, thereby contributing to ocular symptoms.
树突状细胞（DC）在其表面表达高亲和力 IgE 受体（FcεRI），这可能增强其捕获和内化抗原并呈递给 T 淋巴细胞的能力。本研究旨在确定变应性角结膜炎（VKC）患者结膜中 FcεRI（+）DC 的表达是否高于正常对照。
从非变应性和 VKC 患者中获得结膜活检。使用针对 FcεRI 和 DC 标志物 CD1a 抗原的抗体进行双免疫组织化学染色。对每个结膜样本的五个代表性视野进行双阳性细胞计数。
与正常对照组相比，VKC 结膜中 FcεRI（+）CD1a（+）细胞的数量明显更高（VKC 中的平均细胞计数为 21.3，对照组为 5.0，P<0.005）。在正常患者中，表达 FcεRI 的 DC 倾向于局限于上皮层或浅层固有层，但在 VKC 样本中，这些 FcεRI（+）细胞主要集中在更深的固有层。
在 VKC 患者的结膜中，FcεRI（+）DC 数量增加，这与其他关注特应性疾病的研究结果一致。DC 上 FcεRI 的高表达将促进抗原呈递并增强 T 细胞启动，从而导致眼部症状。
