LincRNAs in Mucosal Defense to AIDS Opportunistic Pathogen Cryptosporidium

摘要 在晚期HIV感染者中，隐孢子虫仍然是一种与艾滋病相关的重要机会性感染 诊断或无法访问HAART。这种寄生虫感染人的胃肠道(GI)上皮； 感染也是发展中国家幼儿腹泻的常见原因。目前没有 对感染有完全有效的治疗方法。这种寄生虫被称为“微侵袭”。 粘膜病原体和上皮抗菌防御是粘膜天然抗隐孢子虫的关键 豁免权。鉴于干扰素-γ被认为是预防肠道发育所必需的 隐孢子虫病，决定干扰素-γ介导的胃肠道上皮细胞抗-干扰素的关键细胞调控元件 隐孢子虫的防御，以及它与艾滋病患者和 在年幼的儿童中，仍然是未知的。我们最近的研究表明，干扰素-γ介导的上皮细胞抗-HBs。 隐孢子虫的防御需要诱导特定的长基因间非编码RNA(LincRNAs) 上皮细胞。具体地说，我们已经确定了几个严格在上皮细胞中表达的lincRNAs。 隐孢子虫感染后胃肠道上皮细胞多种上皮lincRNAs表达上调 感染。部分上皮lincRNA的敲除减弱干扰素-γ介导的上皮抗隐孢子虫 防守。基于这些观察，我们假设在胃肠道上皮细胞中诱导上皮间连接RNA 细胞通过模式识别受体信号通路促进粘膜抗隐孢子虫免疫 为干扰素-γ介导的上皮抗菌防御而启动上皮细胞。我们将在体外和体内使用 感染模型和互补的生化、分子和形态方法来定义 上皮lincRNA基因转录对胃肠道上皮细胞模式识别受体信号的影响 隐孢子虫感染后(目标1)，阐明上皮连接RNAs的分子机制 促进干扰素-γ介导的上皮抗隐孢子虫防御(AIM 2)，并破译特异性RNA2的作用 结合蛋白在调节干扰素-γ介导的胃肠道上皮细胞抗隐孢子虫防御中的作用 与上皮lincRNAs的相互作用(目标3)。该提案在概念上是创新的，因为它测试了新的概念 关于粘膜抗菌素防御和肠道隐孢子虫病的发病机制，与 设计和实施新的治疗策略。

Summary Cryptosporidium remains a significant AIDS-related opportunistic infection among people with late HIV diagnosis or without access to HAART. This parasite infects the gastrointestinal (GI) epithelium in humans; infection is also a common cause of diarrhea in young children in developing countries. There is currently no fully effective therapy available for the infection. This parasite has been referred as a “minimally invasive” mucosal pathogen, and epithelial antimicrobial defense is key to mucosal innate anti-Cryptosporidium immunity. Whereas it is well appreciated that IFN-γ is required for preventing development of intestinal cryptosporidiosis, the key cellular regulatory elements that determine IFN-γ-mediated GI epithelial anti- Cryptosporidium defense, as well as its association with the high susceptibility of infection in AIDS patients and in young children, remain unknown. Our recent studies demonstrate that IFN-γ-mediated epithelial anti- Cryptosporidium defense requires the induction of specific long intergenic non-coding RNAs (lincRNAs) in epithelial cells. Specifically, we have identified several lincRNAs that are expressed strictly in epithelial cells. Expression levels of several epithelial lincRNAs are upregulated in GI epithelial cells following Cryptosporidium infection. Knockdown of selected epithelial lincRNAs attenuated IFN-γ-mediated epithelial anti-Cryptosporidium defense. Based on these observations, we hypothesize that induction of epithelial lincRNAs in GI epithelial cells upon pattern-recognition receptors signaling promotes mucosal anti-Cryptosporidium immunity through priming epithelial cells for IFN-γ-mediated epithelial antimicrobial defense. We will use in vitro and in vivo infection models and complementary biochemical, molecular, and morphologic approaches to define the transcription of epithelial lincRNA genes upon pattern-recognition receptor signaling in GI epithelial cells following Cryptosporidium infection (Aim 1), elucidate the molecular mechanisms by which epithelial lincRNAs promote IFN-γ-mediated epithelial anti-cryptosporidial defense (Aim 2), and decipher the roles of specific RNA- binding proteins in modulating IFN-γ-mediated anti-cryptosporidial defense in GI epithelial cells through their interactions with epithelial lincRNAs (Aim 3). The proposal is conceptually innovative as it tests new concepts regarding mucosal antimicrobial defense and the pathogenesis of intestinal cryptosporidiosis, relevant to the design and implementation of new therapeutic strategies.