Cell-cell interactions and subcellular protein dynamics during retrovirus cell-to-cell transmission

逆转录病毒可以通过接触依赖性途径在细胞之间传播。细胞将逆转录病毒颗粒通过细胞间紧密接触的部位转移到邻近的未感染细胞。细胞间传播的概念是基于体外研究，其中供体细胞与未感染细胞建立长期接触以进行病毒转移。因此，组织培养中的细胞间传播可以克服宿主限制因素和广泛中和抗体，这表明在逆转录病毒发病机制中发挥作用。最近的研究，包括我们自己的工作，证实了细胞接触依赖性途径对逆转录病毒在体内传播的贡献。活体成像使我们能够可视化活体动物淋巴组织内的感染细胞和逆转录病毒颗粒，并证实了长寿命细胞接触中细胞间的颗粒转移。这项研究计划的目的是扩大我们对接触依赖性逆转录病毒传播机制的了解。我们将使用模型逆转录病毒小鼠白血病病毒（MLV），研究病毒之间的相关原代白细胞在体外和体内的传播。细胞和逆转录病毒蛋白的亚细胞动力学将在细胞间传递的不同步骤进行分析。单细胞对的高级真实的时间成像将提供关于逆转录病毒传播期间细胞-细胞相互作用的未知细节。细胞动力学信息与单细胞基因表达分析相结合，将有助于揭示逆转录病毒细胞间传播的分子机制。将使用小鼠模型在体内生理条件下确认MLV扩散的关键结果。新的见解，预计将有助于发展新的策略，以干扰体内传播的逆转录病毒感染。

Retroviruses can spread between cells through contact-dependent pathways. Cells transfer retrovirus particles to neighboring uninfected cells across sites of tight cell-cell contact. The concepts of cell-to-cell transmission are based on in vitro studies, in which donor cells establish long-lived contacts with uninfected cells for virus transfer. Cell-to-cell transmission in tissue culture can thereby overcome host restriction factors and broadly neutralizing antibodies, suggesting a role in retroviral pathogenesis. Recent studies, including our own work, confirm the contribution of cell contact-dependent pathways to retrovirus spread in vivo. Intravital imaging enabled us to visualize infected cells and retrovirus particles within lymphoid tissues of living animals and confirmed particle transfer between cells across long-lived cell contacts. The aim of this research proposal is to extend our knowledge about the mechanism of contact-dependent retroviral spread. We will use the model retrovirus murine leukemia virus (MLV) to study virus transmission between relevant primary leukocytes in vitro and in vivo. The subcellular dynamics of cellular and retroviral proteins will be analyzed at different steps during cell-to-cell transmission. Advanced real time imaging of single cell pairs will provide unknown details about cell-cell interactions during retrovirus spread. The information of cellular dynamics combined with single cell gene expression analysis will reveal the molecular mechanism of retrovirus cell-to-cell transmission. Key results of MLV spread will be confirmed under physiologic conditions in vivo using a mouse model. The novel insights are expected to contribute to the development of new strategies to interfere with the dissemination of retroviral infections in vivo.