Background
Caprine Arthritis Encephalitis Virus (CAEV) is a goat lentivirus closely related to HIV except that CAEV never causes AIDS-like disease in goat, in addition, only a minor proportion of infected goats develop inflammatory diseases. One of the main differences that distinguishes CAEV and HIV is the simplicity of CAEV genome organization. CAEV lacks 3 out of 6 regulatory/accessory genes found in HIV. We thought that CAEV/goat is an excellent model to study the functions and the implication of primate lentiviral accessory proteins in the pathogenicity of lentiviruses.