Cell transplantation and inflammation

描述（由申请人提供）：肝脏定向细胞/基因治疗对于许多可能导致肝脏或多个其他靶器官损伤和/或不良反应的遗传、代谢和获得性疾病具有巨大意义。基于我们和其他实验室在过去25年中的工作，肝细胞移植已在约100名患有各种疾病的患者中进行。这些研究表明，啮齿动物模型的见解是适当的，并预测了细胞/基因治疗后的临床结果。此外，人类细胞治疗的初步经验确立了回归动物研究的必要性，特别是确定移植细胞植入的机制，这些机制可以促进肝脏再增殖，以实现上级治疗结果。在最近的研究中，研究表明移植细胞通过多步骤过程植入肝脏。例如，在肝窦中沉积后，移植的肝细胞在肝实质中植入，而在注射到肝动脉中后，移植的肝细胞迅速被破坏。移植细胞进入肝实质需要破坏窦状内皮屏障，使细胞可以通过Disse空间，然后进行肝脏重建，以接受肝实质结构中的移植细胞。然而，细胞移植诱导缺血和组织损伤，导致在同基因或自体细胞的情况下炎症细胞的募集，以及在同种异体细胞的情况下专职免疫细胞的募集，沿着肝窦内皮细胞和肝星状细胞的活化。肝脏中的细胞-细胞相互作用可能是有益的，例如，肝窦内皮细胞的破坏改善了移植细胞的植入，并且肝星状细胞的有益活化释放了细胞保护因子并促进了基质重塑，再次具有上级细胞植入。或者细胞间的相互作用可能是有害的。例如，炎性细胞因子和趋化因子的释放导致移植细胞的显著部分在数小时内被清除，而针对同种异体细胞的额外适应性免疫应答的激活导致细胞在数天内被清除。由于适当的干预措施可以改变这些初始的细胞损失，我们将解决这一假设，即深入了解细胞移植诱导的肝脏炎症机制及其对细胞植入的影响将有助于获得有效的药理学方法，以推进细胞/基因治疗。为了了解细胞扰动的性质，我们将在极好的啮齿动物模型中进行研究，并定义炎症细胞特异性变化，包括相关的趋化因子激活机制以及细胞间相互作用。我们将使用临床相关药物进行药理学研究，以阻断不良机制，改善移植细胞的植入。此外，我们将在进一步的动物模型中检查这些操作对肝脏再生和细胞治疗的功效。总之，这一提议将为肝脏定向细胞/基因治疗提出新的见解，并将对人类健康具有广泛的意义。

DESCRIPTION (provided by applicant): Liver-directed cell/gene therapy is of enormous significance for many genetic, metabolic and acquired conditions that may cause injury and/or adverse effects in the liver or multiple other target organs. Based on work in our and other laboratories over the past 25 years, hepatocyte transplantation has been performed in some 100 people with various conditions. These studies indicated that insights from rodent models were appropriate and predicted clinical outcomes in people after cell/gene therapy. Moreover, initial experiences of cell therapy in people established the need for returning to studies in animals, particularly to define mechanisms in engraftment of transplanted cells that could advance liver repopulation to achieve superior therapeutic outcomes. In more recent studies, it was shown that transplanted cells engrafted in the liver through multi-step processes. For instance, after deposition in liver sinusoids, transplanted hepatocytes engrafted in liver parenchyma, whereas after injection into the hepatic artery, transplanted hepatocytes were promptly destroyed. Entry of transplanted cells in the liver parenchyma required disruption of sinusoidal endothelial barrier, so that cells could travel through the space of Disse, followed by liver remodeling to accept transplanted cells in the parenchymal structure. However, cell transplantation induced ischemia and tissue injury, leading to recruitment of inflammatory cells in the setting of syngeneic or autologous cells, and of professional immunocytes, in the setting of allogeneic cells, along with activation of liver sinusoidal endothelial cells and hepatic stellate cells. Cell-cell interactions in the liver could be beneficial, e.g., disruption of liver sinusoidal endothelial cells improved engraftment of transplanted cells and beneficial activation of hepatic stellate cells released cytoprotective factors and promoted matrix remodeling, again with superior cell engraftment. Or cell-cell interactions could be deleterious. For instance, release of inflammatory cytokines and chemokines resulted in clearance of significant fractions of transplanted cells over several hours, while activation of additional adaptive immune responses against allogeneic cells, led to the clearance of cells over several days. As suitable interventions could alter these initial cell losses, we will address the hypothesis that insights into mechanisms of cell transplantation-induced liver inflammation and its effects on cell engraftment will help obtain effective pharmacological approaches for advancing cell/gene therapy. To understand the nature of cellular perturbations, we will perform studies in superb rodent models and define inflammatory cell-specific changes, including mechanisms in relevant cytokine-chemokine activations, as well as cell-cell interactions. We will perform pharmacological studies with clinically-relevant drugs to block undesirable mechanisms for improving engraftment of transplanted cells. Moreover, we will examine the efficacy of these manipulations for liver repopulation and cell therapy in further animal models. Taken together, this proposal will advance novel insights for liver-directed cell/gene therapy and will be of extensive significance for human health.