My laboratory is interested in the study of the HIV/SIV diversity and pathogenesis. The AIDS pandemic is produced by two different viruses, HIV-1 and HIV-2 that emerged following cross-species transmissions of SIVs, the viruses that naturally infect nonhuman primate species (NHPs) in Africa. As SIVs naturally infect more than 40 species of African non-human primates (NHPs), our major concern is whether or not the remaining viruses infecting other species of African NHPs pose a major threat for humans. Our studies revealed that cross-species transmission of SIVs to humans are not the only requirement for the emergence on new virus strains and suggested that viral adaptation in the new host may play a decisive role for this event. Understanding the mechanisms of viral adaptation to new hosts upon cross-species transmission is of major interest for my laboratory. Using monkey models, we study the mechanisms of viral adaptation associated with viral emergence. Also, in order to better understand the AIDS pathogenesis, we are using various models of SIV infection in natural hosts. In African monkeys SIV are not pathogenic in the vast majority of cases. My group is involved in the study of all currently available models (sooty mangabeys, African green monkeys and mandrills) and generated significant results that challenged core paradigms of SIV pathogenesis. These studies may help us to control HIV infection in patients. Since no vaccine strategy currently developed seems to be effective, these alternative approaches may be essential in the control of AIDS pandemic.