Folate receptor alpha peptide J65–HLA-A*02:01 complex (FRα J65–HLA-A2)

The J65 peptide–HLA-A*02:01 complex is a specific immunological target used in the development of cancer immunotherapies, particularly for Folate Receptor Alpha (FRα)-positive malignancies. J65 is an altered peptide ligand (APL) derived from the E39 peptide (FRα residues 191–199), which is a naturally occurring epitope presented by the HLA-A*02:01 molecule. While E39 is used to prime the immune system, the J65 variant is designed to modulate the T-cell receptor (TCR) signaling of E39-primed T cells, potentially increasing their avidity and expanding the pool of cytotoxic T lymphocytes (CTLs) capable of recognizing low-density antigens on tumor cells. This 'prime-boost' or 'modulation' strategy aims to overcome the immune tolerance often associated with self-antigens like FRα, which is highly expressed in ovarian, breast, and endometrial cancers. Clinical applications primarily involve peptide vaccines (e.g., E39 and J65) administered to prevent disease recurrence by maintaining a robust anti-tumor immune surveillance.

Other names

J65 peptideJ65-HLA-A2 complexFolate receptor alpha (191–199) altered peptide ligandE39 variant peptideFRα(191–199) J65

Stimulation and modulation of peptide-specific cytotoxic T lymphocytes (CTLs) to recognize and eliminate tumor cells expressing Folate Receptor Alpha (FRα).