Tyrosine Phosphatase Regulation of Mucosal Macrophage-Epithelial Cell Cross-talk

摘要/摘要 粘膜表面不断受到环境或微生物制剂的挑战。然而， 天然免疫细胞之间在调节粘膜屏障中相互作用的确切性质仍然是 人们对此知之甚少。这项提议将包括一支具有多样性和互补性的调查团队 研究先天性免疫串扰在调节粘膜屏障中的机制的专业知识 功能。胃肠道的单层上皮细胞是粘膜最基本的成分 屏障：巨噬细胞在粘膜屏障动态平衡和肠道免疫中起关键作用 病原体。以前对这些肠上皮细胞(IEC)之间的通讯的研究主要集中在 巨噬细胞对上皮细胞功能的单向调节。然而，我们认为这种观点有些过头了。 过于简单化，而且存在更复杂的监管电路。我们假设双向串扰 上皮细胞和巨噬细胞之间的回路在上皮细胞和巨噬细胞的动态平衡调节中起着关键作用 通透性和巨噬细胞极化。在这里，我们将研究双向交叉的分子本质。 上皮细胞和巨噬细胞之间的谈话回路的总体目标是确定细胞如何内在地 必需蛋白酪氨酸磷酸酶(TCPTP)的活性调节一种细胞类型的分子变化， 这又可以改变另一个的功能容量。我们将在三个具体目标上检验我们的假设。 目标1将阐述TCPTP如何调节单核细胞分化连续体和巨噬细胞 粘膜动态平衡与肠道局部炎症的极化状态。AIM 2将利用领养 巨噬细胞中TCPTP缺失与IEC相比如何调节肠道通透性的转移实验 以及两种细胞在体内和体外的抗微生物反应性。目标3将识别分子 TCPTP调节这些细胞类型如何相互交叉通信的机制。我们有 为本研究建立了新的小鼠品系和体外共培养模型体系。我们将使用这些模型 系统在一系列创新和既定的方法中，使我们能够机械地定义 磷酸酶对巨噬细胞与上皮细胞之间这些基本相互作用的调节 粘膜屏障功能和巨噬细胞极化的调节。此外，我们将确定这些细胞是否- 内源性磷酸酶调节的串扰机制在小鼠和人类模型中的跨物种应用 系统。这些实验从根本上与先前的工作联系在一起，但毫不含糊地代表着一种令人兴奋的 新的方向，使调查小组的专业知识发挥协同作用。这些研究的结果是 准备在我们对先天的基本机制的理解方面取得重大进展 粘膜表面的免疫生物学和细胞串扰。

SUMMARY/ABSTRACT Mucosal surfaces are under constant challenge from exposure to environmental or microbial agents. However the exact nature of interactions between innate immune cells in the regulation of the mucosal barrier is still poorly understood. This proposal will incorporate a team of investigators with diverse and complementary expertise to investigate the mechanisms of innate immune cross-talk in the regulation of mucosal barrier function. The single layer of epithelial cells lining the GI tract is the most fundamental element of the mucosal barrier while macrophages play a key role in mucosal barrier homeostasis and in immunity to intestinal pathogens. Previous studies of communication between these intestinal epithelial cells (IEC) have focused on unidirectional macrophage regulation of epithelial function. However, we believe that this view is overly simplistic and that a more complex regulatory circuit exists. We hypothesize that bidirectional cross-talk circuits between epithelial cells and macrophages play a key role in both homeostatic regulation of epithelial permeability and macrophage polarization. Here, we will investigate the molecular nature of bidirectional cross- talk circuits between epithelial cells and macrophages with the overall objective to identify how the cell-intrinsic activity of an essential protein tyrosine phosphatase (TCPTP) regulates molecular changes in one cell type, which can in turn modify the functional capacity of the other. We will test our hypothesis in 3 Specific Aims. Aim 1 will address how TCPTP modulates the monocyte differentiation continuum and macrophage polarization status in mucosal homeostasis vs. local inflammation in the intestine. Aim 2 will utilize adoptive transfer experiments to identify how TCPTP deletion in macrophages vs. IEC modulates intestinal permeability and antimicrobial responsiveness of both cell types in vivo and in vitro. Aim 3 will identify molecular mechanisms by which TCPTP regulates how these cell types cross-communicate with each other. We have established novel mouse lines and in vitro co-culture model systems for this study. We will use these model systems in a series of innovative and established approaches, to allow us to mechanistically define phosphatase regulation of these fundamental interactions between macrophages and epithelial cells in the regulation of mucosal barrier function and macrophage polarization. In addition, we will identify if these cell- intrinsic phosphatase regulated crosstalk mechanisms apply across species by using mouse and human model systems. These experiments are foundationally linked to prior work but unequivocally represent an exciting new direction that synergizes the expertise of the investigative team. The results from these studies are poised to generate significant advances in our understanding of fundamental basic mechanisms in innate immunobiology and cellular crosstalk at mucosal surfaces.