Human papillomavirus type 16 E7 peptide–HLA class I complex (HPV16 E7–HLA-I)

The Human papillomavirus type 16 (HPV16) E7 peptide–HLA class I complex is a pivotal immunological target for treating malignancies driven by high-risk HPV infection. This complex is formed when the E7 oncoprotein, a key driver of cellular transformation that inactivates the retinoblastoma (Rb) tumor suppressor, is processed into short peptides and presented on the cell surface by Human Leukocyte Antigen (HLA) class I molecules, most notably HLA-A*02:01 [1.1.3, 1.4.1]. Common immunodominant epitopes include E7 11-19 (YMLDLQPET) and E7 11-20 (YMLDLQPETT), which are recognized by the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes [1.1.1, 1.4.4]. Because the E7 protein is of viral origin and constitutively expressed in tumor cells but absent in healthy tissues, this complex serves as a highly specific target for various immunotherapies, including TCR-engineered T cells (TCR-T), therapeutic vaccines, and TCR-mimic bispecific antibodies [1.3.1, 1.4.5]. Clinical trials have demonstrated that targeting this complex can induce significant tumor regression in patients with metastatic cervical and oropharyngeal cancers [1.3.1, 1.3.2]. However, therapeutic efficacy can be hindered by tumor-mediated immune evasion strategies, such as the downregulation of HLA class I expression or mutations in Beta-2 Microglobulin (B2M) [1.1.2, 1.3.1]. Additionally, safety considerations include the potential for off-target cross-reactivity with similar self-peptides and the risk of cytokine release syndrome following potent T-cell activation [1.1.1, 1.3.1].

Other names

HPV16 E7/MHC-I complexHPV16 E7/HLA-A*02:01 complexHPV16 E7 peptide-MHC complexHPV16 E7-HLA-A2 complex

The mechanism of action involves the specific recognition of the HPV16 E7 peptide–HLA class I complex by the T-cell receptor (TCR) of a CD8+ T cell or a therapeutic agent such as a TCR-engineered T cell or a TCR-mimic antibody. This binding event triggers a signaling cascade that leads to the activation of the T cell, resulting in the release of cytotoxic granules containing perforin and granzymes, which induce apoptosis in the target tumor cell [1.1.3, 1.4.1]. Fusion proteins like CUE-101 further enhance this response by selectively delivering IL-2 signals to E7-specific T cells [1.4.5].