Patient-specific neoantigen–major histocompatibility complex complex

A patient-specific neoantigen–major histocompatibility complex complex refers to a molecular complex formed when a unique, tumor-derived mutated peptide (neoantigen) binds to a specific human MHC (also known as HLA) molecule on the cell surface. These complexes are highly individualized: the peptide sequence is patient/tumor-specific, determined by somatic mutations, and the MHC allele is determined by the patient’s genotype[1][2][3][5]. The complex is essential for direct recognition by cytotoxic T cells, which rely on their T cell receptors to surveil for these non-self peptide–MHC structures. Only a subset of all possible mutation-derived peptides is processed, loaded, and stably presented by MHC class I (for CD8+ T cells) or class II (for CD4+ T cells)[1][4][5]. The identification and validation of immunogenic, tumor-specific neoantigen–MHC complexes lies at the heart of personalized cancer immunotherapy, including neoantigen vaccines and neoantigen-targeted T cell therapies[2][3][5][6]. These complexes are major determinants of both natural and therapy-induced antitumor immune responses, as well as resistance mechanisms such as immune evasion or immunoediting.

Other names

Patient-specific neoantigen–MHC complexPatient neoantigen–MHC complexTumor neoantigen–MHC complexNeoantigen–MHC complexTumor-specific peptide–MHC complexCancer neoepitope–MHC complex

Presentation of patient-unique mutant peptides by MHC on tumor cells or antigen-presenting cells enables recognition and killing by cytotoxic T lymphocytes or engineered T cells Induction of anti-tumor immune responses through tailored immunotherapies that train T cells to recognize these complexes Bypass of central tolerance by exploiting tumor-specific, non-self epitopes, reducing off-tumor toxicity