T-cell receptor on Ag85B- and ESAT-6-specific T cells (TCR (Ag85B/ESAT-6))

The T-cell receptor (TCR) on Ag85B- and ESAT-6-specific T cells is a specialized protein complex on the surface of T lymphocytes that recognizes specific immunodominant antigens from Mycobacterium tuberculosis (Mtb). Ag85B (Antigen 85B) is a mycolyltransferase essential for cell wall biosynthesis, while ESAT-6 (Early Secretory Antigenic Target 6) is a potent virulence factor secreted by the Mtb ESX-1 system (Sorensen et al., 1995). These TCRs function by binding to peptide fragments of Ag85B or ESAT-6 presented by Major Histocompatibility Complex (MHC) molecules on antigen-presenting cells. This binding event initiates a signaling cascade that leads to T-cell activation, proliferation, and the production of pro-inflammatory cytokines like IFN-γ and TNF-α, which are critical for macrophage activation and containment of the pathogen (Lalvani et al., 2001). Therapeutic strategies, particularly subunit vaccines such as H56:IC31 and H1:IC31, target these TCRs to enhance the host's adaptive immune memory against Mtb (Luabeya et al., 2015). Additionally, these TCRs serve as critical biomarkers in diagnostic assays like the Interferon-Gamma Release Assay (IGRA) to detect latent or active tuberculosis infection. Understanding the diversity and affinity of these TCRs is essential for developing more effective immunotherapies and monitoring vaccine-induced protection.

Other names

Ag85B-specific T-cell receptorESAT-6-specific T-cell receptorMtb-specific T-cell receptorAntigen 85B-specific TCREarly Secretory Antigenic Target 6-specific TCR

Antigen-specific activation of T-lymphocytes via TCR-MHC-peptide interaction, leading to Th1 immune response and cytokine release.