B-cell and T-cell antigen receptors (BCR/TCR)

B-cell and T-cell antigen receptors (BCRs and TCRs) are specialized surface proteins on lymphocytes that recognize specific molecular patterns, or epitopes, of pathogens (Janeway et al., 2001). In the context of SARS-CoV-2, these receptors are the primary targets of vaccines designed to elicit a robust adaptive immune response (Wang et al., 2022). Fused antigens combining the Receptor Binding Domain (RBD) of the Spike protein and conserved epitopes of the Nucleocapsid (N) protein are used to stimulate both arms of the immune system (Vaxxinity, 2023). The BCRs recognize the RBD to initiate the production of neutralizing antibodies that block viral entry into host cells, while TCRs recognize processed peptides from the Nucleocapsid protein presented on MHC molecules, leading to the activation of helper and cytotoxic T-cells (PubMed, 35113646). This dual-targeting strategy aims to overcome the limitations of Spike-only vaccines, which may be more susceptible to viral mutations (Nature Communications, 2022). Therapeutic candidates like UB-612 utilize this fusion approach to provide broad-spectrum protection against multiple SARS-CoV-2 variants (ClinicalTrials.gov, NCT04773067). The interaction between these receptors and the fused antigens is critical for establishing long-term immunological memory. Safety considerations for targeting these receptors include avoiding excessive inflammatory responses or potential cross-reactivity with self-antigens. Monitoring the activation of these receptors through biomarkers like antibody titers and T-cell assays is essential for evaluating vaccine efficacy.

Other names

B-cell receptorT-cell receptorAntigen-specific lymphocyte receptorsSARS-CoV-2 specific BCR and TCR

Vaccine-mediated stimulation of B-cell and T-cell receptors to induce neutralizing antibodies and cellular immunity against SARS-CoV-2.