PGT121

PGT121 is a human monoclonal antibody derived from an HIV-1 infected donor and is part of the PGT family of broadly neutralizing antibodies against HIV-1. It has been studied as a potential tool for prevention and therapy in HIV infection.

PGT121 targets a glycan-dependent epitope on the envelope glycoprotein gp120, primarily involving the N332 glycan supersite near the V3 region. The antibody engages glycans as well as protein contacts, blocking conformational changes required for viral entry.

Breadth and potency: In vitro studies show that PGT121 neutralizes a broad panel of HIV-1 isolates across clades, with varying potency. Its activity depends on the glycan landscape of gp120, particularly the presence of the N332 glycan, and some strains with altered glycans show reduced sensitivity.

Research and applications: PGT121 has been used in structural analyses to inform HIV vaccine design and has been evaluated in preclinical models and early-phase human studies to assess safety, pharmacokinetics, and potential for passive protection either alone or in combination with other broadly neutralizing antibodies.

See also broadly neutralizing antibodies, HIV-1 gp120, N332 glycan supersite, and the PGT antibody family.