Matsuda Akira, Okayama Yoshimichi, Ebihara Nobuyuki, Yokoi Norihiko, Hamuro Junji, Walls Andrew F, Ra Chisei, Hopkin Julian M, Kinoshita Shigeru
Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Invest Ophthalmol Vis Sci. 2009 Jun;50(6):2871-7. doi: 10.1167/iovs.08-3022. Epub 2009 Jan 10.
Although the existence of Fc(epsilon)RI-alphabetagamma(2) and Fc(epsilon)RI-alphagamma(2) receptor subtypes was reported, there has been no direct evidence of these two subtypes of Fc(epsilon)RI in vivo. To investigate the existence of these two subtypes of Fc(epsilon)RI in vivo, the authors evaluated the expression of Fc(epsilon)RI-beta in the giant papillae of chronic allergic conjunctivitis and compared the expression level of Fc(epsilon)RI-beta with control conjunctivae using the anti-human Fc(epsilon)RI-beta antibody.
Fc(epsilon)RI-beta expression in giant papillae obtained from patients with atopic keratoconjunctivitis and vernal keratoconjunctivitis in control conjunctivae was evaluated by immunohistochemistry using anti-Fc(epsilon)RI-beta, -alpha, -gamma, and anti-human mast cell tryptase, anti-chymase, anti-basophil, and anti-CD1a antibodies.
Statistical analyses revealed that the densities of Fc(epsilon)RI-beta(+) cells, Fc(epsilon)RI-alpha(+) cells, tryptase(+) cells, and Fc(epsilon)RI-beta(+)/tryptase(+) cells were significantly increased in giant papillae compared with controls. There were two types of Fc(epsilon)RI (alphabetagamma(2) and alphagamma(2)) on the mast cells of the giant papillae. The ratio of the Fc(epsilon)RI-beta(+) cell number/Fc(epsilon)RI-alpha(+) cell number in the giant papillae (0.69 +/- 0.08 [mean +/- SD]) was significantly higher than that of the controls (0.07 +/- 0.16). Fc(epsilon)RI-beta/tryptase double immunostaining revealed that 81% +/- 13% of tryptase(+) cells expressed Fc(epsilon)RI-beta. Fc(epsilon)RI-beta(+) cells were preferentially localized within and around epithelial tissue. The authors also found that Fc(epsilon)RI-beta was expressed by basophils but not by Fc(epsilon)RI-alphagamma(2)-positive Langerhans cells in the giant papillae samples.
Preferential Fc(epsilon)RI-beta expression observed in the mast cells and basophils of giant papillae suggests important roles of Fc(epsilon)RI-beta in the pathophysiology of atopic keratoconjunctivitis and vernal keratoconjunctivitis.
尽管已有报道存在Fc(ε)RI-αβγ₂和Fc(ε)RI-αγ₂受体亚型，但尚无这两种Fc(ε)RI亚型在体内的直接证据。为研究这两种Fc(ε)RI亚型在体内的存在情况，作者评估了慢性过敏性结膜炎巨大乳头中Fc(ε)RI-β的表达，并使用抗人Fc(ε)RI-β抗体将Fc(ε)RI-β的表达水平与对照结膜进行比较。
采用抗Fc(ε)RI-β、-α、-γ抗体以及抗人肥大细胞类胰蛋白酶、抗糜蛋白酶、抗嗜碱性粒细胞和抗CD1a抗体，通过免疫组织化学法评估从特应性角结膜炎和春季角结膜炎患者获取的巨大乳头以及对照结膜中Fc(ε)RI-β的表达。
统计分析显示，与对照相比，巨大乳头中Fc(ε)RI-β(+)细胞、Fc(ε)RI-α(+)细胞、类胰蛋白酶(+)细胞以及Fc(ε)RI-β(+)/类胰蛋白酶(+)细胞的密度显著增加。巨大乳头的肥大细胞上存在两种类型的Fc(ε)RI（αβγ₂和αγ₂）。巨大乳头中Fc(ε)RI-β(+)细胞数/Fc(ε)RI-α(+)细胞数的比值（0.69±0.08[平均值±标准差]）显著高于对照（0.07±0.16）。Fc(ε)RI-β/类胰蛋白酶双重免疫染色显示，81%±13%的类胰蛋白酶(+)细胞表达Fc(ε)RI-β。Fc(ε)RI-β(+)细胞主要定位于上皮组织内及其周围。作者还发现，巨大乳头样本中嗜碱性粒细胞表达Fc(ε)RI-β，而Fc(ε)RI-αγ₂阳性的朗格汉斯细胞不表达。
在巨大乳头的肥大细胞和嗜碱性粒细胞中观察到的Fc(ε)RI-β优先表达表明，Fc(ε)RI-β在特应性角结膜炎和春季角结膜炎的病理生理学中起重要作用。
