X-box binding protein 1-derived HLA-A2 peptide (XBP1-HLA-A2 peptide)

The X-box binding protein 1-derived HLA-A2 peptide is a tumor-associated antigen derived from the spliced form of XBP1 (XBP1s), a transcription factor that is a critical regulator of the unfolded protein response and plasma cell differentiation. In many cancers, particularly multiple myeloma and certain breast cancers, XBP1 is highly overexpressed to manage endoplasmic reticulum stress, leading to the presentation of specific XBP1-derived peptides on the cell surface via the HLA-A2 (MHC Class I) molecule. These peptides, such as the YLFPQLISL or SPWIMLZVP sequences, serve as targets for cancer immunotherapy, including peptide-based vaccines like PVX-410 and adoptive T-cell therapies. By targeting these specific sequences, the immune system can be trained to selectively identify and destroy malignant cells while sparing normal tissues that express lower levels of the protein. Clinical applications focus on stimulating a robust cytotoxic T lymphocyte response to provide long-term immunosurveillance against tumor recurrence. Research indicates that these peptides are highly immunogenic and can induce potent anti-tumor activity in HLA-A2-positive patients.

Other names

XBP1 antigenXBP1-SP peptideX-box binding protein 1 spliced-derived peptidePVX-410 peptides

The peptide acts as a tumor-associated antigen that, when presented by HLA-A2 molecules, stimulates the expansion and activation of antigen-specific cytotoxic T lymphocytes (CTLs) to recognize and lyse XBP1-overexpressing malignant cells.