The long term objectives of this proposal are to develop methodologies and a knowledge base that will enhance the utilization of Feline T-cell lymphotropic lentivirus (FTLV) as a small laboratory animal model of HIV. In Phase I of this proposal, we will develop an FTLV antigen test which will augment our existing antibody tests and provide veterinarians and research scientists with diagnostic tools to monitor FTLV infection. We also propose to begin nucleic acid sequence analysis of FTLV to obtain a better understanding of the genomic organization of this virus and compare these results with the known sequence of HIV and other lentivirus. The FTLV model possesses advantages for the development of drugs to block lentivirus replication and to evaluate a particular approach in the development of lentivirus vaccines.