The objectives of this core are to isolate and propagate primary human leukocytes (monocytes and peripheral blood lymphocytes and maintain a brain bank of pathological tissues [for all projects and cores]. In addition, the core will provide murine bone-marrow-derived macrophages, human and murine neuronal and glial cells for studies of neural progenitors and cell-based nanoformulations in neuroAIDS. Rigorous quality control measures are in place for this well-integrated core. Substantive uses of these facilities were provided to all investigators during the previous funding cycle. Primary human leukocytes will be fractionated into monocytes and lymphocytes from HIV-1, 2 and hepatitis B and C seronegative donors by centrifugal elutriation. Human glia (microglia and astrbcytes) and/or neurons will be obtained from fetal tissues. The neurons, glia, and/or progenitor cells from human and mouse brain tissue will be purified, characterized and provided for experiments (all projects). The Brain Bank will also be operated through this core. Two hundred and thirty-six specimens are available, which include tissues with neuropathological diagnoses of Alzheimer's disease, HIV-1-associated dementia and other neurodegenerative disorders (including but not limited to stroke, Parkinson's disease, and multiple sclerosis). Patients who died of diseases not related to the nervous system serve as age-matched controls. These primary adult human cells and other tissues from Brain Bank will be utilized within to prepare RNA and protein specimen banks. Brain tissue lysates for RNA and protein investigations and frozen and paraffin tissues for immunohistochemistry will be an available resource. These will provide data for common endpoints of disease. In toto, this 'cells and tissue core'will provide all the biological specimens necessary to address research objectives of the program project and utilize the carefully controlled specimens obtained through this infrastructure to investigate neural immunity and its links to neurodegeneration.