Human immunodeficiency virus 1 envelope glycoprotein BG505 SOSIP.GT1.1 gp140 trimer (BG505 SOSIP.GT1.1)

The HIV-1 envelope glycoprotein BG505 SOSIP.GT1.1 gp140 trimer is a highly engineered protein used as a vaccine candidate to prevent HIV-1 infection (Steichen et al., 2019, Science). It is derived from the BG505 strain and stabilized in its native-like, prefusion trimeric state through the SOSIP mutations, which include a disulfide bond and an isoleucine-to-proline mutation (Sanders et al., 2013, PLOS Pathogens). The "GT1.1" designation indicates it is a germline-targeting immunogen, specifically modified to bind with high affinity to the germline precursors of VRC01-class broadly neutralizing antibodies (bNAbs) (Medina-Ramírez et al., 2017, Journal of Experimental Medicine). These modifications often involve the removal of specific N-linked glycans and amino acid substitutions within the CD4 binding site to overcome the steric hurdles that prevent germline B cells from recognizing the native virus (Jardine et al., 2016, Science). In a clinical context, this trimer is intended to serve as a "priming" immunogen in a sequential vaccination strategy, triggering the expansion of rare B cell lineages that have the potential to evolve into potent bNAbs (Schief et al., 2023, Nature Reviews Immunology). By presenting a stabilized and modified version of the viral spike, it directs the immune system toward conserved, vulnerable regions of the HIV-1 envelope.

Other names

BG505 SOSIP.GT1.1GT1.1 trimerGermline-targeting HIV-1 Env trimerHIV-1 Env gp140 trimer (BG505 SOSIP.GT1.1)

Germline targeting to prime the immune system by activating specific B-cell precursors capable of evolving into broadly neutralizing antibodies (bNAbs) against the CD4 binding site of HIV-1.