Muscular Dystrophy Cell Line and Serum Banking Core ABSTRACT The over-arching theme for this MDSRC grant application is to accelerate the translation of novel genetic therapies from the bench into the clinic for individuals with muscular dystrophy. A significant bottleneck in studying pathogenic variants or their correction is the limited proliferative capacity of muscle cells from muscular dystrophy patients, and the process of obtaining cells (muscle biopsy) is invasive. A technique using lentiviral vectors for both hTERT and MyoD delivery to dermal fibroblasts derived from skin biopsy to create myogenic fibroblasts (hereafter called FibroMyoD) will overcome this bottleneck. Through a previous P50 grant we have been very successful creating and banking several hundred fibroblast and FibroMyoD cell lines. The overall objective of the Muscular Dystrophy Cell Line and Serum Banking Core (MD-CLSB Core) will be to continue banking human primary and immortalized cell lines and improve on the method to create myoblasts that will support each of the MDSRC Projects, as well as for serum and plasma banking for exploratory and collaborative projects. The overall objective will be addressed in two specific aims. Aim 1 will expand our unique cell line resource from muscular dystrophy subjects by banking dermal fibroblasts and creating FibroMyoD cell lines and continue banking of serum samples from muscular dystrophy subjects. In Aim 2 we will develop an improved transdifferentiation protocol to generate mature myofibers from the FibroMyoD lines that more closely mimic mature myofibers. We will use novel 3D microenvironments in combination with new transgene delivery to convert dermal fibroblasts to FibroMyoD, different media formulations and extracellular matrix composition to create a more mature myoblast. This MD-CLSB Core will leverage the existing expertise of the Nationwide Children’s Hospital (NCH) Research Institute Cell Line Core, codirected by Drs. Flanigan, MD and Wein, Ph.D. This institutionally supported shared resource has been creating and banking cell lines for over 15 years. The current proposal involves a greatly increased demand on the existing NCH Cell Line Core, and establishment of the MD-CLSB Core will provide the additional resources needed to serve as a resource to both the NCH/OSU and the broader muscle research community. The cell lines generated, and serum samples stored is and will continue to be a valuable resource for the projects of the proposed MDSRC, and the broader muscular dystrophy research community, in direct alignment with the MDSRC mission.