Development of Robust Culture Systems for the Human Splenic Littoral Cell

描述（申请人提供）：脾脏是人体最大的二次免疫系统器官。无脾的人死于压倒性败血症的几率增加。他们患自身免疫性疾病、某些癌症和缺血性心脏病的风险也更高。尽管在其他部位也可以找到相关细胞，但由于脾脏中缺乏有效消除适当靶标的吞噬细胞，死亡率增加。脾白髓的整体组织与淋巴结相似，但脾与淋巴系统不相连。相反，病原体、红细胞、凋亡/坏死细胞、变异细胞和肿瘤细胞都通过血液进入脾脏并离开脾脏。与白髓相比，脾红髓既充当贮液器，又充当过滤器，决定在其中流动的细胞是否被保留、破坏或返回循环。人静脉窦内衬细胞，称为滨海细胞（LC），约占红髓的30%。越来越多的证据表明，这些高度特化的脾细胞是红细胞和其他细胞是否被破坏、保留或返回循环的主要决定因素，尽管调节其功能的机制完全未知。其他人和我们表明，lc不是典型的内皮细胞，因为它们携带多种巨噬细胞和平滑肌相关抗原，是CD8+，缺乏内皮细胞和造血谱系的传统标记。那么，为什么我们对LC函数知之甚少呢？历史证明，收购、净化和培养低成本公司是非常困难的。基于我们最近获得新鲜脾脏的成功，以及识别LC与其他脾细胞区分的标记，我们现在准备进一步分离和分析LC基因/蛋白表达（AIM I）。尽管像LC这样在复杂器官内形成特殊结构的细胞通常很难在体外繁殖，但克服这些限制将代表着理解LC功能的重大进步。我们已经召集了一组内皮细胞生物学家、免疫学家和病理学家专家，他们将在我们开发不同的LC培养系统（AIM II）时为我们提供深入的指导，这些培养系统既与生理学相关又易于处理。这些方法将有助于发现LC功能背后的机制，并导致能够在不同疾病状态（例如败血症、疟疾、血红蛋白病等）中调节脾滤过的治疗方法的发展。

DESCRIPTION (provided by applicant): The spleen is the largest secondary immune system organ in man. Individuals who are asplenic die at an increased rate from overwhelming sepsis. They are also at greater risk of autoimmune disease, some cancers and ischemic cardiac disease. Enhanced mortality is attributed to lack of phagocytes sequestered in spleen that efficiently eliminate appropriate targets, though related cells can be found at other sites. Although the overall organization of splenic white pulp is similar to that of lymph nodes, spleen is not connected to the lymphatic system. Instead, pathogens, RBCs, apoptotic/necrotic, altered and tumor cells all are delivered to and leave the spleen in blood. In contrast to white pulp, splenic red pulp serves as both a reservoir and a filter that determines whether cells coursing therein are retained, destroyed or returned to the circulation. The human venous sinus-lining cell, known as the littoral cell (LC), comprises ~30% of red pulp. Increasing evidence indicates these highly specialized splenocytes are the major determinant of whether RBCs and others are destroyed, retained or returned to the circulation, though the mechanisms that regulate their function are entirely unknown. Others and we showed that LCs are not a classical endothelial cells as they bear multiple macrophage and smooth muscle-associated antigens, are CD8+ and lack traditional markers of endothelial and also hematopoietic lineage. So, why is so little known about LC function? The acquisition, purification and culture of LCs have historically proved very difficult. Based on our recent success in obtaining fresh spleen as well as identifying markers that distinguish LCs from other splenocytes, we are now prepared to further isolate and profile LC gene/protein expression (AIM I). Although cells such as LCs that form specialized structures within complex organs are often hard to propagate ex vivo, overcoming these limitations would represent a significant advance in understanding LC function(s). We have assembled a group of expert endothelial cell biologist-immunologists, and pathologists who will provide us with in depth guidance as we develop diverse LC culture systems (AIM II) that are both physiologically relevant and tractable. These methods will enable discovery of the mechanisms that underlie LC function and lead to development of therapeutics able to modulate splenic filtration in different disease states (e.g. sepsis, malaria, hemoglobinopathies and others).