Cell transplantation and inflammation

描述(申请人提供)：肝脏导向细胞/基因治疗对于许多遗传、代谢和获得性疾病具有巨大的意义，这些疾病可能会导致肝脏或其他多个目标器官的损伤和/或不良影响。根据我们和其他实验室在过去25年的工作，肝细胞移植已经在大约100名不同条件的人身上进行了。这些研究表明，来自啮齿动物模型的见解是适当的，并预测了细胞/基因治疗后人类的临床结果。此外，人类细胞治疗的初步经验确立了重返动物研究的必要性，特别是确定移植细胞的植入机制，可以促进肝脏再繁殖，以获得更好的治疗结果。在最近的研究中，有研究表明，移植细胞通过多步骤过程植入肝脏。例如，在肝窦内沉积后，移植肝细胞植入肝实质，而注入肝动脉后，移植肝细胞立即被破坏。移植细胞进入肝实质需要破坏肝窦内皮细胞屏障，使细胞能够通过Disse间隙，随后肝脏重塑以接受实质结构中的移植细胞。然而，细胞移植导致缺血和组织损伤，导致同种或自体细胞环境中的炎性细胞和同种异体细胞环境中的专业免疫细胞的募集，以及肝窦内皮细胞和肝星状细胞的激活。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，而肝星状细胞的有益激活释放了细胞保护因子，促进了基质重塑，同样具有更好的细胞植入。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在几个小时内被清除，而针对同种异体细胞的额外适应性免疫反应的激活导致细胞在几天内被清除。由于适当的干预可以改变这些最初的细胞损失，我们将解决这样的假设，即深入了解细胞移植引起的肝脏炎症的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来推进细胞/基因治疗。为了了解细胞扰动的本质，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，包括相关细胞因子-趋化因子激活的机制，以及细胞-细胞相互作用。我们将对临床相关药物进行药理学研究，以阻断改善移植细胞植入的不良机制。此外，我们将在进一步的动物模型中检验这些手法在肝脏再生和细胞治疗方面的有效性。综上所述，这项建议将推进肝脏导向细胞/基因治疗的新见解，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.