This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This management study treats Yerkes' colonies of SIV-infected and uninfected sooty mangabeys as cohorts for which a periodic immuno-virological evaluation is conducted and a repository of frozen samples of plasma and PBMCs are stored and made available for selected research projects to both Yerkes and non-Yerkes investigators. An extensive survey of the Yerkes SMs was first completed in 2004 and is now being repeated. To date, we have collected and processed 100 samples during 2006 and will complete the balance of the colony shortly. The samples utilized from this project have been instrumental to several important publications in the field, as listed below. This general approach should also enable us to generate a set of immunological and virological data to conduct a systematic longitudinal assessment of the animals' health status, with specific focus on the course of SIV infection. This set of data will also allow the rapid and effective identification of SM with specific immunological and/or virological features.