The Cell and Immunology Core will to continue to offer assays to extend the work of laboratories at Temple University and of outside collaborators who want to add immune or histological/pathological end-points to their studies. Dr. Eisenstein will supervise the work to be carried out in Aims 1, 2, and 4. A major addition to the Core in this renewal is Dr. Yuri Persidsky. Trained as a pathologist, he will supervise new services offered by the Cell and Immunology Core as related to analysis of tissue as described in Aim 3. In addition, he will bring his expertise in HIV-1 infection of relevant human cells and the blood-brain barrier (BBB) to the Core, as well as projects using the HIV-1-infected humanized NOD.Cg-Prkdcscid ll2rgtm1Wjl /SzJ (NSG mice or huNSG) mouse model that recapitulates key features of infection in humans.