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

总结/摘要 粘液表面经常受到环境或微生物的挑战。然而 先天免疫细胞在调节粘膜屏障中相互作用的确切性质仍然是 不太了解。该提案将包括一个调查小组， 专门知识，以研究先天免疫串扰在调节粘膜屏障中的机制 功能衬在胃肠道上的单层上皮细胞是胃肠道粘膜的最基本组成部分。 而巨噬细胞在粘膜屏障稳态和肠道免疫中起关键作用。 病原体以前的研究这些肠上皮细胞（IEC）之间的通信集中在 单向巨噬细胞调节上皮功能。然而，我们认为，这种观点过于 简单化，并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稳态调节中起关键作用。 渗透性和巨噬细胞极化。在这里，我们将研究双向交叉的分子性质- 讨论上皮细胞和巨噬细胞之间的电路，总体目标是确定细胞内在的 必需蛋白酪氨酸磷酸酶（TCPTP）的活性调节一种细胞类型中的分子变化， 这反过来又可以改变另一个的功能能力。我们将在三个具体目标中检验我们的假设。 目的1将阐述TCPTP如何调节单核细胞分化连续体和巨噬细胞 粘膜稳态中的极化状态与肠中的局部炎症。目标2将采用 转移实验，以确定巨噬细胞中TCPTP缺失与IEC如何调节肠通透性 以及两种细胞类型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 建立了用于本研究的新型小鼠品系和体外共培养模型系统。我们将使用这些模型 系统的一系列创新和既定的方法，使我们能够机械地定义 磷酸酶调节巨噬细胞和上皮细胞之间的这些基本相互作用， 调节粘膜屏障功能和巨噬细胞极化。此外，我们将确定这些细胞- 通过使用小鼠和人模型跨物种应用内在磷酸酶调节的串扰机制 系统.这些实验与先前的工作有着基础性的联系，但无疑代表了一种令人兴奋的 新的方向，协同调查小组的专业知识。这些研究的结果是 准备在我们对先天免疫的基本机制的理解方面产生重大进展， 免疫生物学和粘膜表面的细胞串扰。

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.