T-cell receptor recognizing recombinant Pseudomonas aeruginosa Exoprotein A-derived peptide–MHC class II complex (TCR-rEPA-MHCII)

T-cell receptors (TCRs) recognizing recombinant Pseudomonas aeruginosa Exoprotein A (rEPA)-derived peptide–MHC class II complexes are essential mediators of the immune response to conjugate vaccines. rEPA serves as a carrier protein, providing the necessary T-cell epitopes to stimulate CD4+ T-cell help for B-cell responses against otherwise poorly immunogenic antigens, such as bacterial polysaccharides [PubMed: 24931613]. These TCRs specifically bind to rEPA peptides presented by MHC class II molecules on the surface of antigen-presenting cells. This interaction initiates a signaling cascade that leads to T-cell proliferation and the production of cytokines like IL-4 and IL-21, which are vital for B-cell isotype switching and memory formation [Frontiers in Immunology, 2018]. In clinical applications, rEPA-based vaccines target various infectious diseases, and the presence of these specific TCRs is a key determinant of vaccine success. Monitoring these TCRs can serve as a biomarker for assessing the cellular immune response to immunization. However, challenges such as carrier-induced epitopic suppression or HLA polymorphism-related variations in peptide presentation must be considered during vaccine development [Vaccine, 2013].

Other names

rEPA-specific T-cell receptorPseudomonas Exotoxin A-specific T-cell receptorCarrier-specific T-cell receptorExoprotein A-specific TCR

These TCRs recognize specific peptides derived from the rEPA carrier protein presented on MHC class II molecules. This recognition activates CD4+ T cells, which then provide essential signals (cytokines and surface ligands) to B cells, enabling high-affinity antibody production and memory formation against the vaccine's target antigen [PubMed: 24931613].