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的途径在细胞之间传播。细胞通过细胞间紧密接触的部位将逆转录病毒颗粒转移到邻近的未感染细胞。细胞间传播的概念建立在体外研究的基础上，在体外研究中，捐赠者细胞与未感染的细胞建立长期接触，以进行病毒传播。组织培养中的细胞间传播因此可以克服宿主限制因素和广泛的中和抗体，这表明在逆转录病毒的发病机制中发挥了作用。最近的研究，包括我们自己的工作，证实了细胞接触依赖的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着的动物淋巴组织中的受感染细胞和逆转录病毒颗粒，并确认通过长期细胞接触在细胞之间进行颗粒转移。这项研究计划的目的是扩大我们对接触依赖型逆转录病毒传播机制的了解。我们将使用逆转录病毒模型小鼠白血病病毒(MLV)来研究病毒在相关原代白细胞之间的体外和体内传播。细胞和逆转录病毒蛋白的亚细胞动力学将在细胞间传播的不同阶段进行分析。单细胞对的先进实时成像将提供逆转录病毒传播期间细胞间相互作用的未知细节。细胞动力学信息结合单细胞基因表达分析将揭示逆转录病毒细胞间传播的分子机制。MLV传播的关键结果将在体内生理条件下使用小鼠模型进行确认。这些新的见解有望有助于开发新的战略，以干预逆转录病毒感染在体内的传播。

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.