Passages inter-espèces des virus de l'immunodéficience humaine et simienne chez les primates

More than 40 simian immunodeficiency viruses (SIV), the animal counter-part of HIV have been described. The genomic structures of these viruses are similar to those of HIV. The emergence of HIV is the result of cross species transmissions from apes to human. Central Africa is characterized by a remarkable high HIV diversity: all the HIV subtypes from Major group (M), the majority of recombinant forms, variants of groups M, O, N and P are found. This situation reflects the anteriority of the epidemic in this region. HIV-1 group M represents the majority of isolates characterized to date with 9 different subtypes (A-K) and over 40 recombinant forms. HIV-1 group O is characterized by a high genetic diversity. The discovery of the rare cases of HIV-1 group N was the first evidence of an inter-species transmission of SIV from chimpanzees to humans and the importance of recombination between lentiviruses in primates. In 2009, an atypical variant, HIV-1 group P phylogeneticaly related to SIV from gorillas has been reported in a Cameroonian woman living in France. Evidence of inter-species transmission of immunodeficiency viruses from primates to humans is reinforced by the similarity of viral genomes, the phylogenetic affinities and the prevalence of SIV in their natural hosts and the geographical overlap between HIV and SIV.