Remyelination in Multiple Sclerosis: a PET-MR Longitudinal Study Investigating Individual Profiles of Myelin Repair and the Contribution of Neuroinflammation

Multiple Sclerosis (MS) is an inflammatory disease where the immune cells invade the central nervous system and destroy an essential element of nerve conduction: the myelin. An interesting feature observed in some patients is a regenerative process, called remyelination, which leads to the production of new myelin. However, the extent of remyelination is very heterogeneous among patients, only a minority of patients show a really efficient repair process along the disease course. In this project, our aim is to explore in vivo the biological mechanisms leading to a successful remyelination in some patients and to a failure in remyelination in others. With this purpose in mind we propose to develop a translational research platform where patients with multiple sclerosis will be investigated in vivo for their potential of remyelination through a follow-up with recently developed imaging technologies using a synergistic combination of magnetic resonance imaging (MRI) and positron emission tomography (PET) to visualize and quantify myelin and neuroinflammation. In parallel blood immune cells from patients will be sampled and profiled to investigate how they could influence remyelination. This part will consist in i) grafting patients' lymphocytes in experimental rodent models of demyelination to characterize how they could promote or inhibit remyelination; ii) performing a functional and multi-omics analysis of peripheral macrophages and analyse relationships with remyelination profiles; iii) profiling T lymphocytes at the single cell level to associate specific subpopulation of the T cells with the remyelination potential assessed in patients with MRI/PET images and in grafted animals.