INFLAMMATORY MECHANISMS IN VIRAL OTITIS MEDIA

急性中耳炎(AOM)和病毒性上呼吸道感染(URI)是影响人类人口的两种最常见的疾病，占患者发病率和医疗费用的很大比例。流行病学和实验研究表明，URI在AOM的发病机制中起着因果作用。具体地说，病毒可以侵入中耳(ME)空间并引发炎症反应，最终导致中耳渗出(液体)形成和随之而来的症状(疼痛、听力丧失)。病毒暴露后引起人类ME炎症反应的分子事件尚未确定。使用病毒接种鼻腔和气管支气管组织的研究表明，启动炎症事件是上皮细胞通过局部细胞因子的产生而介导的。由于ME通常不包含白细胞聚集物，因此病毒性中耳炎的启动事件很可能也是由上皮细胞介导的。本研究的长期目标是研究ME黏膜对病毒暴露的反应(S)，以更好地了解AOM的启动事件。这些知识将有助于为这种重大疾病开发新的治疗方法。本项目的目标是：(1)在实验室正常的中耳上皮细胞培养系统中进行甲型流感病毒攻击实验，并利用逆转录-聚合酶链式反应(RT-PCR)、原位杂交和酶联免疫吸附试验(ELISA)检测IL-1、IL-1α、IL-1β、IL-6、IL-8、IL-10和肿瘤坏死因子(TNF)-α基因的表达；(2)评估“中耳炎倾向”患者的ME上皮细胞对相同细胞因子的反应；以及(3)在这些模型中评估几种潜在的抑制物质的效果。这些实验的结果将提供更好的了解病毒性中耳炎的启动事件，并有望导致这种疾病的新疗法的开发。首席调查员(PI)成功完成这一奖项将为未来作为独立调查员的大规模研究提供额外的研究培训和职业发展。

Acute otitis media (AOM) and viral upper respiratory tract infections (URIs) represent the two most common diseases affecting the human population, and account for substantial patient morbidity and health care costs. Epidemiological and experimental studies suggest that URIs play a causal role in the pathogenesis of AOM. Specifically, viruses can invade the middle ear (ME) space and invoke an inflammatory response that culminates in ME effusion (fluid) formation and consequent symptoms (pain, hearing loss). The molecular events responsible for the inflammatory response of the human ME following viral exposure have not been characterized. Studies using viral inoculation of nasal and tracheobronchial tissues suggest that the initiating inflammatory events are epithelium-mediated through local cytokine production. Since the ME normally does not contain aggregates of leukocytes, it is likely that the initiating events in viral otitis media are epithelium-mediated as well. The long-term goal of the present study is to investigate the ME mucosal response(s) to viral exposure in an effort to better understand the initiating events in AOM. Such knowledge will help develop new therapies for this significant disease. The goals of this project are to: (1) perform influenza A viral challenge experiments in the laboratory's normal ME epithelial cell culture system and measure expression of the interleukin (IL,)-1alpha, IL-1beta, IL-6, IL-8, IL-10 and tumor necrosis factor (TNF)-alpha genes using reverse transcriptase- polymerase chain reaction (RT-PCR), in situ hybridization, and enzyme-linked immunoabsorbent assays (ELISA); (2) evaluate the same cytokine responses in ME epithelial cells derived from "otitis-prone" individuals; and (3) evaluate the efficacy of several potentially inhibitory substances in these models. The results of these experiments will provide a better understanding of the initiating events in viral otitis media and, hopefully, will lead to the development of novel therapies for this disease. Successful completion of this award by the principal investigator (PI) will provide the added research training and career development for future large-scale studies as an independent investigator.