Human leukocyte antigen A*02 peptide-binding groove (HLA-A*02)

The HLA-A*02 peptide-binding groove is a critical structural feature of the Human Leukocyte Antigen A*02 molecule, which belongs to the Major Histocompatibility Complex (MHC) class I family. This groove is responsible for capturing and presenting short intracellular peptides to the T-cell receptors of CD8+ cytotoxic T lymphocytes, a process essential for immune surveillance against pathogens and malignancies [1.1.1, 1.3.1]. The groove's architecture, defined by its polymorphic amino acid residues, determines the specific 'motif' of peptides it can bind, typically 8-11 amino acids in length [1.2.2, 1.3.1]. In therapeutic contexts, the HLA-A*02 peptide-binding groove is a major target for cancer immunotherapies, including bispecific T-cell engagers like tebentafusp, which bind the groove when it presents specific tumor antigens such as gp100 [1.4.3]. It is also the focus of peptide-based vaccines and adoptive cell therapies that utilize engineered TCRs to recognize specific peptide-HLA complexes [1.4.4, 1.5.1]. Challenges in targeting this site include the high degree of HLA polymorphism across populations and the potential for severe immune-related adverse effects, such as cytokine release syndrome or off-target recognition of healthy tissues [1.4.3, 1.5.3].

Other names

HLA-A2 peptide-binding cleftMHC class I antigen-binding grooveHLA-A*02:01 binding pocketAntigen-binding groove of HLA-A*02

The primary mechanism of action for drugs targeting the HLA-A*02 peptide-binding groove involves the recognition of specific peptide-HLA (pHLA) complexes by engineered T-cell receptors (TCRs) or TCR-mimetic antibodies, which then recruit and activate T cells to destroy target cells. Peptide vaccines work by supplying exogenous immunogenic peptides that occupy the groove to stimulate a specific immune response. Additionally, experimental small molecules can bind within the groove to alter the repertoire of presented peptides or block the presentation of specific antigens.