The CFAR 1rnmunology Core is designed to provide both state-of-the-art flow cytometric capabilities as well as expertise and technical assistance for numerous immunological assays desired by members of the CFAR. The core is dedicated to providing such service in a timely, cost-effective, and efficient manner. The core is headed by Dr. Dorothy E. Lewis, who has over 20 years of flow and immunologic experience and a staff of well- trained personnel. The core consists of two flow cytometers, an analytical one and a high speed cell sorter, a BL-2 containment room for immunological assays, and a confocal microscope. Cytokine measurement expertise is provided by Dr. Reuben at M.D. Anderson Cancer Center, located across the street from Baylor College of Medicine, on a fee-for- service basis. In the previous funding period, the core has been essential for studies involving immune function in pediatric HW and has facilitated interactions with clinical and basic science researchers. In particular, the core was key for studies of Tat kinase activity in primary lymphocytes, in detection of cytokine messages, and in analysis of CD8+ T cell function in HWinfected children. The core has also developed new assays for the users, including improved HIV-speciflc cytotoxic T lymphocyte assays and cytokine quantitation in tissues. A range of services is provided by this core which include flow cytometry, lymphocyte function assays and confocal microscopy. Training on the use of instrumentation and data interpretation is also a key component of the core. The core will be overseen by a committee. The Core Director will have responsibility for day-to-day running of the core, and priorities for usage are prescribed in a standardized manner mcluding an appropriate charge-back system. It is anticipated that at least 19 investigators at Baylor College of Medicine and at The University of Texas, UTMB-Galveston, Texas A&M University, and Tulane University School of Medicine will benefit. ~