Promoting remyelination through cell transplantation therapies in a model of viral‐induced neurodegenerative disease

Multiple sclerosis (MS) is a central nervous system (CNS) disease characterized by chronic neuroinflammation, demyelination, and axonal damage. Infiltration of activated lymphocytes and myeloid cells are thought to be primarily responsible for white matter damage and axonopathy. Several United States Food and Drug Administration‐approved therapies exist that impede activated lymphocytes from entering the CNS thereby limiting new lesion formation in patients with relapse‐remitting forms of MS. However, a significant challenge within the field of MS research is to develop effective and sustained therapies that allow for axonal protection and remyelination. In recent years, there has been increasing evidence that some kinds of stem cells and their derivatives seem to be able to mute neuroinflammation as well as promote remyelination and axonal integrity. Intracranial infection of mice with the neurotropic JHM strain of mouse hepatitis virus (JHMV) results in immune‐mediated demyelination and axonopathy, making this an excellent model to interrogate the therapeutic potential of stem cell derivatives in evoking remyelination. This review provides a succinct overview of our recent findings using intraspinal injection of mouse CNS neural progenitor cells and human neural precursors into JHMV‐infected mice. JHMV‐infected mice receiving these cells display extensive remyelination associated with axonal sparing. In addition, we discuss possible mechanisms associated with sustained clinical recovery. Developmental Dynamics 248:43–52, 2019. © 2018 Wiley Periodicals, Inc. Key Findings JHMV infection of the CNS results in immune‐mediated demyelination associated with axonal damage. Engraftment of mouse or human progenitor cells promotes clinical recovery and repair under the right experimental conditions. A better understanding of molecule and cellular mechanisms contributing to stem cell‐mediated repair may lead to development of new therapies for treating demyelinating diseases.