Human immunodeficiency virus type 1 envelope glycoprotein gp120 glycan shield (HIV-1 gp120 glycan shield)

The HIV-1 gp120 glycan shield is a dense layer of host-derived N-linked glycans that covers the surface of the viral envelope glycoprotein, serving as a primary mechanism for immune evasion by masking underlying protein epitopes (Sanders et al., 2002). A specific region of this shield, known as the high-mannose patch, is the target of the broadly neutralizing antibody 2G12, which recognizes a cluster of terminal Manα1,2Man residues (Calarese et al., 2003). Unlike most antibodies that recognize protein surfaces, 2G12 utilizes a unique domain-swapped structure to achieve high-affinity binding to these carbohydrate motifs (Doores et al., 2010). This interaction is critical for neutralizing a wide range of HIV-1 isolates by sterically hindering the virus's ability to interact with host cell receptors like CD4 and coreceptors (Trkola et al., 2005). Targeting this glycan shield is a major focus in HIV vaccine development and passive immunotherapy, aiming to elicit or provide antibodies that can penetrate the sugar coat of the virus. Therapeutic challenges include the virus's ability to shift glycosylation sites to escape neutralization, a phenomenon known as the glycan shield evolution.

Other names

2G12 epitopegp120 high-mannose patchHIV-1 carbohydrate shieldgp120 glycan cluster

Neutralization of viral entry by binding to high-mannose glycans on gp120, preventing receptor binding and membrane fusion.