HIV-2 Interaction with Cell Receptors

Although sharing several properties, human immunodeficiency virus 1 and 2 (HIV-1 and HIV-2) have shown some important differences in vivo. A significant amount of data suggest that HIV-2 is in general less virulent than HIV-1. This reduced virulence is revealed by a longer asymptomatic period, a minor T-cell depletion and lower viral load. Due to its inherently attenuated phenotype, the study of HIV-2 infection constitutes an exceptionally good model to understand virologic and pathogenic mechanisms that enable the human host to cope with an HIV infection for such a long period of time and may help to learn more about HIV-1 pathogenesis, and to viral-cell interactions, opening to new strategies to vaccines or therapeutic design. The molecular mechanisms underlying this reduced virulence are far from being fully characterized or even identified. In this review the contribution of virus-cell interactions for this phenotype will be discussed with particular emphasis in the events involved in binding of envelope glycoproteins to cell co receptors.