Peptide-major histocompatibility complex-T cell receptor interface

The **Peptide-major histocompatibility complex-T cell receptor (Peptide-MHC-TCR) interface** is the structural and functional contact zone where a T cell receptor (TCR) binds to a peptide presented by a major histocompatibility complex (MHC) molecule on an antigen-presenting cell[1][4][5]. This interaction is fundamental to the cellular arm of the adaptive immune response, dictating the specificity and activation of T cells. The interface comprises three main components—the peptide (usually 8–15 amino acids long), the MHC molecule (often highly polymorphic), and the TCR itself (formed by variable α/β chains)[5]. Structural studies show that the TCR typically recognizes the antigenic peptide by using its hypervariable complementarity-determining region 3 (CDR3) loops, while the CDR1 and CDR2 loops primarily interact with the MHC molecule[1][4]. The docking geometry and conformational changes at the interface are critical for antigen specificity and avoidance of off-target or autoimmune responses[1][3][4][5]. Extensive structural variability and flexibility at this site allow recognition of diverse peptide antigens, but also pose challenges for predicting specificity and engineering safe therapeutics[1][2][6]. The Peptide-MHC-TCR interface is an active target in immunotherapy, including TCR-engineered cell therapies, peptide-MHC vaccines, and structural-based drug design aiming to manipulate immune recognition or tolerance[4][5][6]. Safety concerns largely stem from the potential to trigger undesirable immune reactions due to cross-reactivity or loss of TCR specificity, underscoring the need for robust structure-guided approaches in clinical applications[4][6].

Other names

TCR:pMHC interfaceT cell receptor-peptide-MHC interfaceT cell receptor:peptide-MHC interfaceTCR-antigen-MHC interface

Modulation of antigen recognition specificity; Induction of T cell activation and cytotoxicity; Allosteric modulation of TCR-pMHC binding; Enhanced immune synapse formation