Facts and Hopes in Cancer Antigens Recognized by T Cells

T cells are key effectors of our immune response against tumors and exert their antitumor effects upon recognizing a variety of tumor-specific peptides presented by HLA molecules on the surface of tumor cells. The identification of the tumor-specific antigens of a given tumor is not required for immune checkpoint therapy (ICT), which mainly reactivates existing tumor-specific T cells together with T cells of unknown specificities. To decrease the activation of non-tumor-specific T cells, active or passive immunizations against tumor-specific antigens are considered. These immunizations require the identification of at least some of the tumor-specific antigens displayed on the tumor cells of a patient. While this has become an easy task for tumors with a large number of mutations generating neoantigens, it remains difficult for the remainder. Here, we review some facts about human tumor-specific or tumor -associated antigens, as well as some hopes for their future use in cancer immunotherapy.

Automated summary

T cells play a crucial role in the immune response against tumors by recognizing tumor-specific antigens presented by HLA molecules on tumor cells. Immune checkpoint therapy (ICT) can reactivate existing tumor-specific T cells, even without identifying the specific antigens. To minimize the activation of non-tumor-specific T cells, immunizations targeting tumor-specific antigens are considered. However, identifying these antigens is challenging for certain tumors. In this review, we discuss the current understanding of human tumor-specific and tumor-associated antigens and their potential use in cancer immunotherapy.