Biophysical basis of single cell force spectroscopy

单细胞力谱的生物物理基础

• 批准号: RGPIN-2016-04082
• 负责人: Shi, Yan
• 金额: $ 2.26万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614828
• 关键词: Biophysical; basis; single; cell; force

Historically, immunological research has been a protein-centric endeavor, with signaling events often defined as biochemical changes of polypeptides. How biophysical factors play into this scheme has been mostly overlooked. Funded by our last NSERC support, we have used atomic force microscopy (AFM)-based single cell force spectroscopy (SCFS) to elucidate several important immunological events that are driven by biophysical changes at the cell membrane. We have found that particulate substances ligate surface lipid moieties with substantial intensity, causing rearrangement of the bilayer membrane. This lipid sorting aggregates signaling molecules and triggers phagocytosis and dendritic cell activation. Our previous work therefore introduces the concept of force and physical disturbance into the realm of immune activation. In this proposal, we substantially move this concept forward and suggest that the immune system is constantly under the regulation of biophysical factors. We provide evidence that regulatory T cells, a group of CD4+ T cells essential to control autoimmunity, bind strongly to dendritic cells and suppress the latter’s ability to mount unwanted immune activation. We also show that peripheral lymphoid volume or the number of total immune cells in the system is regulated by steady state interaction between T cells and dendritic cells. Namely the physical binding between these two cell types provides a trickling signal to control the expansion and contraction of immune cells. We propose to use AFM and photonic force microscopy to further study the essential parameters of these interactions and signaling events associated with these biophysical changes. The outcomes of this work will open a new page in immunological research, and introduce biophysics as an essential aspect of immune regulation. Because the topic of research is of great importance in public health and technologies used to carry the work are in line with the central mission of NSERC, we believe that the investment here will be highly rewarding in years to come.

从历史上看，免疫学研究一直是以蛋白质为中心的奋进，信号事件通常被定义为多肽的生化变化。生物物理因素在这一体系中的作用大多被忽视了。在我们最后一次NSERC支持的资助下，我们使用了基于原子力显微镜（AFM）的单细胞力光谱（SCFS）来阐明细胞膜生物物理变化驱动的几个重要免疫学事件。我们已经发现，颗粒物质连接表面脂质部分与实质性的强度，引起双层膜的重排。这种脂质分选聚集信号分子并触发吞噬作用和树突细胞活化。因此，我们先前的工作将力和物理干扰的概念引入免疫激活领域。在这个提议中，我们实质上将这个概念向前推进，并建议免疫系统不断受到生物物理因素的调节。我们提供的证据表明，调节性T细胞，一组控制自身免疫必不可少的CD4+ T细胞，强烈结合树突状细胞，并抑制后者的能力，安装不必要的免疫激活。我们还表明，外周淋巴体积或系统中的总免疫细胞的数量由T细胞和树突状细胞之间的稳态相互作用调节。也就是说，这两种细胞类型之间的物理结合提供了一个涓滴信号来控制免疫细胞的扩张和收缩。我们建议使用原子力显微镜和光子力显微镜进一步研究这些相互作用的基本参数以及与这些生物物理变化相关的信号事件。这项工作的成果将在免疫学研究中打开新的一页，并将生物物理学作为免疫调节的一个重要方面。由于研究主题在公共卫生领域非常重要，而且用于开展这项工作的技术符合NSERC的中心使命，我们相信，在这里的投资将在未来几年获得很高的回报。