In tissues, cells have their physical space constrained by neighbouring cells and by the extracellular matrix. In the frame of our PROMICO ERC project, our team studied the effect of physical confinement on normal and cancer cells that are dividing and migrating. One of the devices we developed, the cell confiner, was meant to quantitatively control two key parameters of the cell environment: its geometry and its surface chemical properties. Using this tool, we discovered important effects of confinement on cell physiology, in particular on the capacity of cells to divide and migrate efficiently. Based on these results, we think that cell confinement could be used as a powerful cell conditioning technology, to change the cell state and offer new opportunities for fundamental research in cell biology, but also in cell therapies and drug screening.
The goal of the present ACTICELL project was to assess the value proposition that the confinement method developed in PROMICO ERC project can be used industrially to mechanically condition the state of living cells in culture.
Our initial method to confine cells was not adapted to large scale cell conditioning applications, because the throughput and reliability of the device was too low and because the recovery of cells after confinement remained poorly controlled. We thus developped a robust and versatile cell confiner adapted to use in cell biology lab, in academy and in industry, with no prior experience in micro-fabrication. In addition, we performed proofs of concept of its use for its application in cell based therapies, such as cancer immunotherapy, by testing the possibility to mechanically activate dendritic cells.
In the course of the project, we achieved two main tasks:
1) We developed a new cell confiner. To this end, a new start-up company, 4DCell, was launched by partners of this project in 2017. This company more generally develops and commercializes advanced cell culture and cell conditioning devices. The company developed two new version of the cell confiner which are now commercially available.
2) We performed a study on dendritic cells, showing that, at a specific level of deformation, they can be switched to a mature state, the state in which they can trigger an immune response, for exemple against tumor cells. The study also identified a specific molecular pathway, associated with the cell nuclear envelope, involved in the mechanical activation of dendritic cells. The interest of this confinement induced dendritic cell maturation is that it is not triggered by a pathogenic signal, and could define a new type of mature state induced by the tissue micro-environment. This could help understand how physical tumor associated factors can modulate dendritic cell activation and thus their capacity to participate in the immune response against the tumor. In addition, studies of normal mesenchymal and cancer cells demonstrated that confinement at a degree that induced nuclear envelope ruptures could promote cell senescence in normal cells and an invasive phenotype in cancer cells - both aspects could be reverted by depletion of a cytoplasmic nuclease responsible for inducing DNA damage upon cell confinement. These results are very promising to extend the study of the effect of cell confinment to the contexts of aging and cancer.
