Functional characterization of cell-specific differences of L. major-containing phagolysosomes in macrophages and dendritic cells

被沙蝇叮咬进入皮肤后，利什曼原虫主要寄生虫被巨噬细胞(MF)和树突状细胞(DC)吞噬。侵染期的前鞭毛虫的主要生活型是由皮肤寄生的MF占据，在这个过程中，寄生虫在含有寄生虫的吞噬噬菌体--寄生虫空泡(PV)内转化为专有的细胞内生命形式。相比之下，DC优先摄取无鞭毛虫。寄生虫被这两种吞噬细胞(MF、DC)内化后的细胞内事件尚未得到很好的描述。然而，寄生虫在这些细胞中的命运和它们的细胞行为明显不同，例如，只在DC中观察到IL-12的释放，而在MF中没有观察到。最近，我们发现细胞内、吞噬酶体内的TLR9信号对感染后DC来源的IL-12的产生至关重要。因此，我们现在打算更详细地研究各自含主要乳杆菌的PVs中存在的成分和条件。使用透射电子显微镜和无偏系统生物学方法绘制吞噬小泡蛋白质组的变化和差异图，以绘制两种细胞类型感染后宿主和病原体转录本的变化，我们的目标是识别参与吞噬和PV维持的宿主和病原体来源的因素，以及表征对细胞类型内遇到的不同环境的适应的病原体来源的因素。

After transmission into the skin by the bite of a sand fly, Leishmania major protozoan parasites are phagocytosed by macrophages (MF), and dendritic cells (DC). The infectious stage promastigote L. major life form is taken up by skin-resident MF, in which the parasite transforms into the obligate intracellular life form within the parasite-containing phagolysosome, the parasitophorous vacuole (PV). In contrast, DC preferentially ingest amastigotes. The intracellular events after parasite internalization by these two phagocytes (MF, DC) are not well characterized. However, the fate of the parasite within these cells and their cellular behaviour differ significantly, e.g. IL-12 release is only observed in DC, but not MF. Recently, we identified intracellular, phagolysosomal TLR9 signalling as critical for DC-derived IL-12 production after infection. Thus, we now intend to further study the constituents and conditions that exist in the respective L. major-containing PVs in more detail. Using TEM and unbiased systems biology approaches to map changes and differences in the proteome of phagocytic vesicles to chart changes in both host and pathogen transcriptomes after infection in the two cell types, we aim to identify host as well as pathogen-derived factors involved in phagocytosis and PV maintenance as well as pathogen-derived factors characterizing adaptation to the different environments encountered inside the cell types.