This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Supported by an existing RO1 grant, we showed in a mouse model of Parkinson's disease (PD) that hematopoietic stem cell (HSC)-derived macrophage mediated delivery of glial cell line-derived neurotrophic factor (GDNF) is very effective to protect dopamine neurons, which are the major cell type affected in PD. The neuroprotective effect of GDNF is well accepted but how to deliver it to the brain is problematic. Systemic delivery is ineffective due to the blood-brain barrier, while direct CNS delivery is challenging. Our approach to deliver GDNF by macrophages is innovative. Before we move this to the clinic, we need to confirm the neuroprotective and restorative effect of HSC-based macrophage delivery of GDNF in a non-human primate. We choose marmoset for a few reasons: 1) we have the resource (SNPRC) locally;2) marmosets have been established as PD models with MPTP treatment;and 3) many other advantages including their small size.