B cell receptor (BCR) specific for HIV-1 CH505TF gp120 epitopes (BCR (HIV-1 CH505TF gp120))

The B cell receptor (BCR) specific for HIV-1 CH505TF gp120 epitopes is a primary target in the development of germline-targeting HIV-1 vaccines. This receptor is defined by its specificity for the envelope glycoprotein (gp120) of the CH505 transmitted/founder (TF) virus, which initiated the development of the CH103 broadly neutralizing antibody (bNAb) lineage in an infected individual (Liao et al., Nature, 2013). The biological function of this BCR is to recognize viral antigens and initiate the B cell immune response, including proliferation and affinity maturation through somatic hypermutation (Bonsignori et al., Cell, 2016). In vaccine strategies, engineered immunogens like CH505TF gp120 or its stabilized trimers are used to engage these specific BCRs on naive B cells to guide the immune system toward producing bNAbs that can neutralize a wide range of HIV-1 variants (Saunders et al., Science, 2019). This target is central to overcoming the challenges of HIV-1's extreme diversity and the difficulty of eliciting broad protection through traditional vaccination methods. By binding to these receptors, immunogens trigger signal transduction pathways that lead to B cell proliferation and the eventual secretion of high-affinity antibodies. Understanding the structural interaction between the CH505TF gp120 epitopes and the BCR is essential for overcoming the challenges of HIV-1's high mutational rate and glycan shielding.

Other names

CH103-lineage B cell receptorHIV-1 CH505 envelope-specific B cell receptorCH505TF gp120-reactive BCRGermline CH103 B cell receptor

Binding of engineered HIV-1 envelope immunogens to the B cell receptor triggers receptor clustering and downstream signaling, initiating B cell activation, clonal expansion, and somatic hypermutation to drive the maturation of broadly neutralizing antibodies (Liao et al., Nature, 2013; Bonsignori et al., Cell, 2016).