Kaifi J T, Hall L R, Diaz C, Sypek J, Diaconu E, Lass J H, Pearlman E
Departments of Medicine, Ophthalmology, and Pathology, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, Ohio, USA.
Invest Ophthalmol Vis Sci. 2000 Nov;41(12):3856-61.
A murine model of helminth-induced keratitis (river blindness) that is characterized by a biphasic recruitment of neutrophils (days 1-3) and eosinophils (days 3+) to the cornea has been developed. The purpose of this study was to determine the relative contribution of P- and E-selectin in recruitment of these inflammatory cells from limbal vessels to the corneal stroma.
P- and E-selectin gene knockout (-/-) mice were immunized with antigens extracted from the parasitic helminth Onchocerca volvulus. One week after the last immunization, parasite antigens were injected directly into the corneal stroma. Mice were killed on days 1 and 3 postchallenge, and eyes were immunostained with either anti-eosinophil major basic protein (MBP) or with anti-neutrophil Ab. The number of cells in the cornea was determined by direct counting.
Recruitment of eosinophils to the cornea was significantly impaired in P-selectin(-/-) mice (63.9% fewer eosinophils on day 1 [P: = 0.0015], and 61% fewer on day 3 [P: < 0.0001]) compared with control C57BL/6 mice. In contrast, P-selectin deficiency had no effect on neutrophil recruitment to the cornea. There was no inhibition of eosinophil and neutrophil migration to the corneas of E-selectin(-/-) mice, indicating that there is no direct role for this adhesion molecule in helminth-induced keratitis.
The present study demonstrates that P-selectin is an important mediator of eosinophil recruitment to the cornea. P-selectin interactions may therefore be potential targets for immunotherapy in eosinophil-mediated ocular inflammation.
已建立一种蠕虫诱导性角膜炎（河盲症）的小鼠模型，其特征为中性粒细胞（第1 - 3天）和嗜酸性粒细胞（第3天及以后）双相性募集至角膜。本研究的目的是确定P-选择素和E-选择素在这些炎症细胞从角膜缘血管募集至角膜基质过程中的相对作用。
用从寄生蠕虫旋盘尾丝虫提取的抗原免疫P-选择素和E-选择素基因敲除（-/-）小鼠。末次免疫一周后，将寄生虫抗原直接注射到角膜基质中。在攻击后第1天和第3天处死小鼠，用抗嗜酸性粒细胞主要碱性蛋白（MBP）或抗中性粒细胞抗体对眼睛进行免疫染色。通过直接计数确定角膜中的细胞数量。
与对照C57BL/6小鼠相比，P-选择素（-/-）小鼠中嗜酸性粒细胞向角膜的募集明显受损（第1天嗜酸性粒细胞减少63.9% [P = 0.0015]，第3天减少61% [P < 0.0001]）。相反，P-选择素缺乏对中性粒细胞向角膜的募集没有影响。E-选择素（-/-）小鼠的嗜酸性粒细胞和中性粒细胞向角膜的迁移没有受到抑制，表明该黏附分子在蠕虫诱导性角膜炎中没有直接作用。
本研究表明P-选择素是嗜酸性粒细胞向角膜募集的重要介质。因此，P-选择素相互作用可能是嗜酸性粒细胞介导的眼部炎症免疫治疗的潜在靶点。
