Major histocompatibility complex class II presenting Mycobacterium tuberculosis Ag85B, ESAT-6, and CFP-10 peptides (MHC II-Ag85B/ESAT-6/CFP-10)

The Major Histocompatibility Complex (MHC) class II complex presenting Ag85B, ESAT-6, and CFP-10 peptides is a critical immunological target for the development of vaccines and diagnostics against Mycobacterium tuberculosis (Mtb). Ag85B (FbpB) is a major secretory protein involved in cell wall synthesis, while ESAT-6 (EsxA) and CFP-10 (EsxB) are key virulence factors secreted by the Mtb Type VII secretion system (UniProt P9WNP3, P9WQP3, P9WQP1). These antigens are processed by antigen-presenting cells and displayed on MHC class II molecules to be recognized by CD4+ T cells, which is essential for a protective Th1-mediated immune response (PubMed: 25617100). This specific peptide-MHC complex is the primary target for several advanced subunit vaccine candidates, such as GamTBvac and H56:IC31, which aim to induce or boost the frequency of antigen-specific T cells (PubMed: 31980646, PubMed: 22238245). Recognition of this complex by T-cell receptors triggers the release of pro-inflammatory cytokines like interferon-gamma and tumor necrosis factor-alpha, which are vital for macrophage activation and control of Mtb infection (PubMed: 24560618). Consequently, this complex serves as both a therapeutic target for immunization and a diagnostic target for assessing T-cell reactivity in tuberculosis patients.

Other names

MHC II-TB antigen complexHLA-DR-Ag85B-ESAT6-CFP10MHC II-EsxA-EsxB-FbpBMHC class II-mycobacterial peptide complex

Induction of antigen-specific CD4+ T-cell mediated immunity through the recognition of peptide-MHC II complexes by T-cell receptors.