Role of CD14 and TLR4 in Urothelial Response to LPS.

描述（由申请人提供）：尿路感染导致每年约960万次就诊，20%的女性在一生中会发生尿路感染。大多数（70-90%）尿路感染是产生脂多糖（LPS）的革兰氏阴性细菌的结果，并且LPS是负责导致疼痛和炎症的细胞反应的革兰氏阴性细菌的细胞壁的组分。各种器官系统（GI、呼吸道、泌尿系统）的粘膜作为抵抗革兰氏阴性菌感染的第一道先天性防御发挥作用;然而，调节尿路上皮细胞对LPS的反应的细胞过程仍然未知。尽管其他研究者报道了尿路上皮细胞不表达CD 14（LPS的主要同源细胞受体），但最近的一份报告描述了人膀胱粘膜中存在CD 14的信息，并且我们实验室的初步研究证明了人尿路上皮细胞中存在信息和蛋白。这些细胞还表达Toll样受体4（TLR 4），其似乎提供响应于LPS的信号传导的跨膜途径。 尿路上皮细胞具有产生细胞因子的能力，所述细胞因子募集并激活白细胞。本研究的目的是验证CD 14和TLR 4在尿路上皮对LPS的反应中起关键作用的假设。 使用培养的人尿路上皮细胞和小鼠的CD 14或TLR 4的遗传破坏，我们将调查的尿路上皮细胞在体外和体内的LPS的功能性CD 14和TLR 4的存在或不存在下的反应。此外，我们将确定可溶性形式的CD 14是否放大了尿路上皮细胞对LPS的反应。所提出的实验将更好地定义这些受体在先天免疫的其他组分存在（体内）和不存在（体外）的情况下参与尿路上皮细胞对LPS的应答。我们预计，这些研究将提供基础，继续调查，以确定其他蛋白质，可能参与这一过程，并剖析信号通路，翻译LPS结合尿路上皮细胞转化为细胞反应。这项研究的长期目标是确定策略，以尽量减少疼痛和有害细胞的影响与膀胱炎由于脂多糖生产革兰氏阴性细菌。

DESCRIPTION (provided by applicant): Urinary tract infections result in approximately 9.6 million doctor visits annually, and 20% of women will develop a urinary tract infection during their lifetime. A majority (70-90%) of urinary tract infections are the result of gram-negative bacteria that produce lipopolysaccharide (LPS), and LPS is the component of the cell wall of gram-negative bacteria responsible for cellular response resulting in pain and inflammation. The mucosa of a variety of organ systems (GI, respiratory, urinary) functions as the first line of innate defense against infection by gram-negative bacteria; however, cellular processes that regulate the response of urothelial cells to LPS remain unknown. Although other investigators have reported that urothelial cells do not express CD14 (the primary cognate cellular receptor for LPS), a recent report described the presence of message for CD14 in human bladder mucosa, and preliminary investigations in our laboratory demonstrated the presence of message and protein in human urothelial cells. These cells also express Toll-Like Receptor 4 (TLR4), which appears to provide the transmembrane pathway for signaling in response to LPS. Urothelial cells have the capacity to produce cytokines which recruit and activate leukocytes. The goal of this research is to test the hypothesis that CD14 and TLR4 play a crucial role in the response of the urothelium to LPS. Using cultures of human urothelial cells and mice with genetic disruption of either CD14 or TLR4, we will investigate the response of the urothelium in vitro and in vivo to LPS in the presence or absence of functional CD14 and TLR4. Further, we will determine whether or not the soluble form of CD14 amplifies the response of urothelial cells to LPS. The proposed experiments will better define participation of these receptors in the response of urothelial cells to LPS in the presence (in vivo) and absence (in vitro) of other components of innate immunity. We anticipate that these studies will provide the foundation for continued investigations to identify additional proteins that may participate in this process and dissect signaling pathways which translate LPS binding by urothelial cells into cellular response. The long-range goal of this research is to identify strategies to minimize pain and harmful cellular effects associated with cystitis due to LPS-producing gram-negative bacteria.