Antigen specific immune responses and mechanisms of impaired antigen presentation in HPV positive and negative head and neck cancer

Background Antigen-specific immune response is a hallmark of cancer immunotherapy. Potential antigens in head and neck squamous cell carcinoma (HNSCC) include tumor-associated antigens (TAAs), mutation-associated neoantigens (MANAs) and viral proteins, including high-risk human papillomavirus (HPV) proteins. Studies combining multiple antigens for cellular therapy renewed interest in TAAs. While intratumoral expression of antigens is frequent, immunotherapy does not induce durable tumor regression in the majority of HNSCC patients. Impaired HLA class I antigen processing as a key factor of immune evasion in HNSCC has been recognized previously, but the precise mechanisms remain elusive.