Dark Antigen

Dark antigens are a novel class of tumor-specific targets derived from the non-canonical or dark regions of the genome, which comprise approximately 98% of human DNA (Ouspenskaia et al., Nature 2022). These regions, including introns, untranslated regions (UTRs), and transposable elements, were previously thought to be non-coding but are frequently transcribed and translated in cancer cells due to epigenetic and transcriptional dysregulation (Laumont et al., Nature Communications 2018). Once translated, these cryptic peptides are processed and presented on the cell surface by Major Histocompatibility Complex (MHC) molecules, making them visible to the immune system. Because dark antigens are typically absent in healthy tissues, they offer a high degree of tumor specificity and a reduced risk of central tolerance (Enara Bio, 2024). This makes them ideal candidates for various immunotherapeutic approaches, including cancer vaccines, TCR-engineered T-cell therapies, and antibody-based treatments. Research into dark antigens aims to expand the pool of targetable neoantigens beyond traditional exonic mutations, potentially providing therapeutic options for patients with cold tumors or low mutational burdens.

Other names

Non-canonical antigenCryptic antigenHidden antigenUnconventional antigenDark matter-derived antigen

Dark antigens are presented on the surface of tumor cells by Major Histocompatibility Complex (MHC) molecules, where they are recognized by T-cell receptors (TCRs), leading to the targeted destruction of the cancer cell by the immune system (Laumont et al., 2018).