Human telomerase reverse transcriptase (hTERT) peptide epitopes presented on HLA class II (hTERT/HLA-II)

Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of the telomerase enzyme, which is responsible for maintaining telomere length and is overexpressed in approximately 85-90% of all human cancers (Shay & Wright, 2006). While hTERT is essential for the indefinite proliferative capacity of malignant cells, its expression is highly restricted in normal adult somatic tissues, making it a nearly universal tumor-associated antigen (Kim et al., 2002). Peptide epitopes derived from hTERT and presented on Human Leukocyte Antigen (HLA) class II molecules are specifically recognized by CD4+ T helper cells, which are vital for orchestrating a comprehensive and durable anti-tumor immune response (Schroers et al., 2002). These CD4+ T cells provide essential help to CD8+ cytotoxic T cells through the secretion of cytokines like interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), and can also exert direct cytotoxic effects against HLA class II-positive tumor cells (Inderberg et al., 2022). Therapeutic interventions targeting these epitopes, such as the UV1 peptide vaccine, aim to induce long-lasting immune memory and overcome the immunosuppressive tumor microenvironment (Brunsvig et al., 2020). Because hTERT is a driver protein necessary for tumor survival, targeting its epitopes reduces the likelihood of immune escape through antigen loss (Kyte et al., 2011).

Other names

hTERT-derived CD4+ T cell epitopesTelomerase MHC class II epitopeshTERT-HLA-DR/DP/DQ complexesTelomerase reverse transcriptase helper T cell epitopes

Induction of hTERT-specific CD4+ T helper cell responses to coordinate anti-tumor immunity and provide help for cytotoxic T cells (Inderberg et al., 2022).