Germline VRC01-class B cell receptor (Germline VRC01-class BCR)

Germline VRC01-class B cell receptors (BCRs) are the unmutated, naive precursors of a potent class of broadly neutralizing antibodies (bNAbs) that target the CD4-binding site of the HIV-1 envelope glycoprotein (Jardine et al., Science 2013). These receptors are characterized by their derivation from the IGHV1-2 germline gene and typically feature a short, 5-amino acid light chain complementarity-determining region 3 (LCDR3) (Zhou et al., Science 2010). Because the native HIV-1 envelope does not bind these germline precursors with sufficient affinity to trigger an immune response, they have become the primary focus of germline-targeting vaccine strategies (Schief et al., Science 2021). Engineered immunogens, such as the eOD-GT8 60mer nanoparticle, are designed to specifically bind and activate these rare B cells in the human repertoire (Leggat et al., Nature 2022). The goal of targeting these BCRs is to initiate a multi-step affinity maturation process that eventually leads to the production of mature VRC01-class bNAbs capable of neutralizing diverse HIV-1 strains (IAVI, 2021). This approach represents a paradigm shift in vaccinology, moving from traditional antigen presentation to the precision guidance of B cell evolution.

Other names

VRC01-class precursorsIGHV1-2-expressing naive B cell receptorsVRC01-class germline-encoded BCRsCD4-binding site-directed germline BCRsUnmutated VRC01-class B cell receptors

Germline-targeting immunogens bind specifically to naive B cells expressing VRC01-class germline receptors, triggering their activation, proliferation, and entry into germinal centers to initiate somatic hypermutation toward broadly neutralizing antibody development (Schief et al., Science 2021).