Fleiszig S M, Zaidi T S, Ramphal R, Pier G B
Channing Laboratory Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115.
Infect Immun. 1994 May;62(5):1799-804. doi: 10.1128/iai.62.5.1799-1804.1994.
To gain access to the corneal epithelium and cause infections keratitis, bacterial pathogens must first interact with ocular surface factors that could affect bacterial adherence. In this study, we demonstrated that the mucus layer, and, in particular, the mucin fraction of mucus, modulated adherence to intact corneal epithelium of Pseudomonas aeruginosa but not that of Staphylococcus aureus or Streptococcus pyogenes. Removal of endogenous mucus from rat or rabbit eyes increased the adherence of P. aeruginosa by 3- to 10-fold. Ocular mucus obtained from rat eyes, porcine stomach mucin, or bovine submaxillary gland mucin inhibited adherence of P. aeruginosa to uninjured corneal epithelium. The mucin fraction of ocular mucus, purified by ultracentrifugation, was found to contain the inhibitory activity, and inhibition was demonstrated at concentrations of mucin as low as 35 micrograms/ml. Ocular mucin was the only material tested that inhibited adherence of P. aeruginosa to an injured cornea. However, the binding of P. aeruginosa to immobilized substrates in vitro did not predict which fraction would possess antiadherence activity: bacteria bound well to whole ocular mucus, mucin, the nonmucin fraction of ocular mucus, and dilute human tears as well as to porcine stomach mucin and bovine submaxillary gland mucin. The effectiveness of the mucin fraction of ocular mucus at inhibiting the binding of P. aeruginosa to the cornea implies that this material is a barrier that protects the surface of the eye from P. aeruginosa adherence.
为了侵入角膜上皮并引发感染性角膜炎，细菌病原体必须首先与可能影响细菌黏附的眼表因素相互作用。在本研究中，我们证明黏液层，尤其是黏液中的黏蛋白部分，可调节铜绿假单胞菌对完整角膜上皮的黏附，但对金黄色葡萄球菌或化脓性链球菌则无此作用。去除大鼠或兔眼的内源性黏液可使铜绿假单胞菌的黏附增加3至10倍。从大鼠眼获得的眼黏液、猪胃黏蛋白或牛颌下腺黏蛋白可抑制铜绿假单胞菌对未损伤角膜上皮的黏附。通过超速离心纯化的眼黏液黏蛋白部分被发现具有抑制活性，在低至35微克/毫升的黏蛋白浓度下即可表现出抑制作用。眼黏蛋白是唯一被测试的能抑制铜绿假单胞菌黏附损伤角膜的物质。然而，铜绿假单胞菌在体外与固定化底物的结合并不能预测哪一部分会具有抗黏附活性：细菌能很好地结合到全眼黏液、黏蛋白、眼黏液的非黏蛋白部分、稀释的人泪液以及猪胃黏蛋白和牛颌下腺黏蛋白上。眼黏液黏蛋白部分抑制铜绿假单胞菌与角膜结合的有效性表明，这种物质是一种保护眼表面免受铜绿假单胞菌黏附的屏障。
