[ODP-071] 生きた細菌表面に結合した細胞外膜小胞の物性測定
Bacterial cells release nanometer-sized extracellular membrane vesicles (MVs) to deliver cargo molecules for mediating a variety of biological processes. Although, multiple functions of MVs have been identified, the detailed molecular mechanism of transporting the cargos by MVs remains unclear. Here, we aim to elucidate the mechanism of signal transport mediated by MVs. We used phase imaging of high-speed atomic force microscopy (AFM) to image the small fragile MVs in living cell surface. The phase imaging in high-speed AFM can image compositional differences in sample surfaces by detecting physical properties, such as adhesion and/or elasticity. In this study, we compared Paracoccus denitrificans living cells surface after and before adding MVs isolated from the P. denitrificans cultures. After adding MVs, we succeeded in observations of MVs attaching process in the cell surface. The phase images showed that MVs bound to cell surface had higher adhesion and/or elasticity than cell surface. Interestingly, adhesion and/or elasticity of some MVs in cell surface were decreased during time-lapse AFM imaging. This result suggests that the chemical components of MV particles were changed after bound to the cell surface. We will discuss about whether delivering molecules is mediated by MVs attaching to cell surface.