Huang Ling C, Reins Rose Y, Gallo Richard L, McDermott Alison M
University of Houston, College of Optometry, Houston, Texas 77204-2020, USA.
Invest Ophthalmol Vis Sci. 2007 Oct;48(10):4498-508. doi: 10.1167/iovs.07-0274.
To examine the clinical progression and innate immune responses during Pseudomonas aeruginosa (PA) keratitis in cathelicidin-deficient (KO) mice.
PA (ATCC 19660) keratitis was induced in KO mice and wild-type (WT) littermates generated on a 129/SVJ background. Clinical score and histopathology were used to monitor the progression of infection at postinfection (PI) days 1, 3, 7, 14, and 21. Mouse corneas were harvested for viable bacteria quantitation, and myeloperoxidase (MPO) assays were performed to determine the number of infiltrating neutrophils. ELISA was used to quantitate interleukin (IL)-1beta, IL-6, macrophage inflammatory peptide (MIP)-2, keratinocyte-derived chemokine (KC), tumor necrosis factor (TNF)-alpha, and vascular endothelial growth factor (VEGF) levels in the corneas.
WT mice were resistant (cornea healed), whereas KO mice showed increased susceptibility (corneas failed to recover by 21 days or perforated) to PA infection. Clinical scores were significantly elevated in the infected corneas of KO mice versus WT mice at 7, 14, and 21 days PI. Absence of cathelicidin resulted in significantly delayed clearance of PA in the cornea and an increased number of infiltrating neutrophils at 1, 3, 7, and 14 days PI. KO mice also exhibited differential expression of protein levels for IL-1beta, IL-6, MIP-2, KC, TNF-alpha, and VEGF up to day 21 PI compared with the WT mice.
Cathelicidin-deficient mice showed considerable susceptibility to PA keratitis. The present study demonstrates direct in vivo evidence that endogenous expression of cathelicidin provides defense against corneal PA infection indicating its importance in host innate immunity at the ocular surface.
研究在缺乏cathelicidin（KO）的小鼠中铜绿假单胞菌（PA）角膜炎的临床进展和固有免疫反应。
在129/SVJ背景下产生的KO小鼠和野生型（WT）同窝仔鼠中诱导PA（ATCC 19660）角膜炎。在感染后（PI）第1、3、7、14和21天，使用临床评分和组织病理学来监测感染的进展。采集小鼠角膜进行活菌定量，并进行髓过氧化物酶（MPO）测定以确定浸润中性粒细胞的数量。使用酶联免疫吸附测定（ELISA）来定量角膜中白细胞介素（IL）-1β、IL-6、巨噬细胞炎性肽（MIP）-2、角质形成细胞衍生趋化因子（KC）、肿瘤坏死因子（TNF）-α和血管内皮生长因子（VEGF）的水平。
WT小鼠具有抵抗力（角膜愈合），而KO小鼠对PA感染表现出易感性增加（角膜在21天内未恢复或穿孔）。在PI第7、14和21天，KO小鼠感染角膜的临床评分显著高于WT小鼠。缺乏cathelicidin导致角膜中PA的清除显著延迟，并且在PI第1、3、7和14天浸润中性粒细胞数量增加。与WT小鼠相比，直至PI第21天，KO小鼠还表现出IL-1β、IL-6、MIP-2、KC、TNF-α和VEGF蛋白质水平的差异表达。
缺乏cathelicidin的小鼠对PA角膜炎表现出相当大的易感性。本研究证明了直接的体内证据，即cathelicidin的内源性表达提供了针对角膜PA感染的防御，表明其在眼表宿主固有免疫中的重要性。
