Human leukocyte antigen (HLA) complex (HLA)

The Human leukocyte antigen (HLA) class I and II peptide-binding groove is a specialized structural domain within the Major Histocompatibility Complex (MHC) that plays a central role in the adaptive immune system. HLA Class I molecules (HLA-A, -B, -C) are expressed on nearly all nucleated cells and present endogenous peptides to CD8+ cytotoxic T-cells, while HLA Class II molecules (HLA-DR, -DQ, -DP) are primarily on antigen-presenting cells and present exogenous peptides to CD4+ helper T-cells (Janeway et al., Immunobiology, 2001). This presentation is essential for the recognition of viral infections, intracellular bacteria, and tumor-derived neoantigens. In the context of pharmacology, certain drugs like Abacavir can bind directly within the peptide-binding groove (specifically HLA-B*57:01), altering the groove's specificity and causing the presentation of self-peptides that trigger severe hypersensitivity reactions (Illing et al., Nature, 2012). Conversely, therapeutic strategies such as peptide vaccines and certain immunomodulators like Glatiramer acetate aim to occupy or modify the groove to direct the immune response toward pathogens or away from self-tissues in autoimmune diseases (Fridkis-Hareli et al., Journal of Immunology, 1998).

Other names

Major Histocompatibility ComplexMHCHLA class IHLA class IIMHC class IMHC class IIHLA-AHLA-BHLA-CHLA-DRHLA-DQHLA-DP

Drugs can interact with the HLA peptide-binding groove by competitively inhibiting the binding of pathogenic or self-peptides, or by binding non-covalently to the groove to alter its shape and the repertoire of peptides it can present, which can either trigger a therapeutic immune response or cause idiosyncratic hypersensitivity reactions.