ESAT-6-specific T-cell receptor (ESAT-6 TCR) (ESAT-6 TCR)

The ESAT-6-specific T-cell receptor (TCR) is a heterodimeric surface protein found on adaptive immune cells, primarily CD4+ and CD8+ T-lymphocytes, that recognizes the Early Secretory Antigenic Target-6 (ESAT-6) protein [Sorensen et al., 1995]. ESAT-6 is a major virulence factor and immunodominant antigen secreted by Mycobacterium tuberculosis via the ESX-1 secretion system [Brodin et al., 2004]. The TCR functions by binding to specific ESAT-6-derived peptides presented by Major Histocompatibility Complex (MHC) molecules on the surface of infected macrophages or other antigen-presenting cells [Lewinsohn et al., 2007]. This interaction is a cornerstone of the adaptive immune response against tuberculosis, leading to T-cell activation, clonal expansion, and the production of protective cytokines such as interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) [Grotzke et al., 2009]. In therapeutic development, ESAT-6-specific TCRs are being utilized in the design of TCR-engineered T-cell therapies (TCR-T) aimed at treating multi-drug resistant tuberculosis by augmenting the cellular immune response [Zhang et al., 2022]. Furthermore, these receptors are the biological basis for diagnostic Interferon-Gamma Release Assays (IGRAs), which detect latent or active TB infection by measuring the reactivity of a patient's T-cells to ESAT-6 antigens [Pai et al., 2014]. The specificity of this receptor makes it a high-value target for monitoring vaccine efficacy and developing precision immunotherapies against mycobacterial diseases.

Other names

Early secretory antigenic target-6-specific T-cell receptorEsxA-specific T-cell receptorMycobacterium tuberculosis-specific T-cell receptor

The receptor binds to ESAT-6 peptides presented by MHC molecules, triggering T-cell activation, proliferation, and the secretion of pro-inflammatory cytokines (e.g., IFN-gamma) to control Mycobacterium tuberculosis infection [Lewinsohn et al., 2007; Zhang et al., 2022].