Recent strategies targeting HIV glycans in vaccine design

Although efforts to develop a vaccine against HIV have so far met with little success, recent studies of HIV-positive patients with strongly neutralizing sera have shown that the human immune system is capable of producing potent and broadly neutralizing antibodies (bnAbs), some of which neutralize up to 90% of HIV strains. These antibodies bind conserved vulnerable sites on the viral envelope glycoprotein gp120, and identification of these sites has provided exciting clues about the design of potentially effective vaccines. Carbohydrates have a key role in this field, as a large fraction of bnAbs bind carbohydrates or combinations of carbohydrate and peptide elements on gp120. Additionally, carbohydrates partially mask some peptide surfaces recognized by bnAbs. The use of engineered glycoproteins and other glycostructures as vaccines to elicit antibodies with broad neutralizing activity is therefore a key area of interest in HIV vaccine design.