B cell receptors recognizing HIV-1 Envelope 763 SOSIP v8.2 epitopes (BCR-763SIP8)

B cell receptors (BCRs) recognizing HIV-derived 763SIP8 epitopes are the primary immunological targets for the 763SIP8/MPLA-5 vaccine candidate. These receptors are membrane-bound immunoglobulins on the surface of B cells that specifically bind to the 763 SOSIP v8.2 protein, a recombinant, stabilized trimeric form of the HIV-1 envelope glycoprotein (Env) derived from a specific clinical isolate (763) known for early induction of neutralizing antibodies. The interaction between the 763SIP8 immunogen and these BCRs is designed to stimulate the development of broadly neutralizing antibodies (bNAbs) by engaging germline B cell precursors and guiding their maturation. In clinical settings, these BCRs serve as a focal point for evaluating vaccine immunogenicity, with their frequency and affinity serving as key indicators of a successful immune response against HIV-1.

Other names

HIV-1 Env-specific B cell receptors763 SOSIP-specific BCRs763SIP8-binding B cell receptorsB cell receptors specific for HIV-1 763 SOSIP v8.2

The 763SIP8 protein, a stabilized SOSIP v8.2 trimer, acts as an immunogen that binds to the B cell receptors (BCRs) on the surface of naive or memory B cells. This binding event, facilitated by the MPLA-5 adjuvant (Monophosphoryl Lipid A in liposomes), triggers the BCR signaling pathway, leading to B cell activation, clonal expansion, and differentiation into antibody-secreting plasma cells or memory B cells capable of neutralizing HIV-1.