Mechanical Characterization of Human Monocyte Derived Antigen Presenting Cells

T cells are at the root of the immune response protecting living organisms against pathogens and tumor cells, and have recently been shown to respond to mechanical changes. The activation of T cells triggering the immune response requires the formation of cell-cell interaction between T lymphocytes and various antigen presenting cells (APC) (tumor cells, dendritic cells, macrophages, B lymphocytes...). Yet, little is known about the rigidity of these different APCs. In the present study we use the single-cell microplates assay to measure the mechanical properties of human monocyte derived APCs. We show that APCs present a wide range of stiffnesses, that are affected during differentiation, maturation and in response to inflammatory signals.Noteworthily, dendritic cells, the most efficient APC for T cell activation, present the closest rigidity to T cell rigidity. These results suggest that cell stiffness could be an important factor in immune cell-cell interactions and T cell mediated responses. We will then show preliminary studies on the role of rigidity in T cell activation ; involving laying T cells on substrates mimicking APCs rigidities and monitoring T cell activation and T cell / substrate interface organization.View Large Image | View Hi-Res Image | Download PowerPoint Slide