[Neutralizing antibodies and human immunodeficiency virus type 1 (HIV-1) infection]

Most viral vaccines induce the production of neutralizing antibodies that prevent infection. In the case of HIV-1, no immunogen is able to generate antibodies that neutralize the highly diverse variants. Nevertheless, studies conducted these recent years greatly improved our understanding of the role of these antibodies during natural infection, the mechanisms developed by the virus to escape neutralization, and the modes of action of some rare antibodies with broad specificity. If neutralizing anibodies do not seem to play a major role in controlling the disease progression, we now know that several broadly neutralizing antibodies are able to confer sterilizing immunity in experimental animal models, even at concentrations close to those found in some infected individuals. The best characterized antibodies recognize conserved envelope epitopes, such as the CD4 receptor binding site, the membrane-proximal external region (MPER) of gp41, a glycan-dependent epitope, and a quaternary epitope of the trimeric envelope glycoprotein spikes. However, other epitopes targeted by broadly neutralizing antibodies remain to be identified. Their characterization is a major step towards the development of immunogens presenting major neutralization epitopes.