A T cell receptor specific for an HLA-A*03:01-restricted epitope in the endogenous retrovirus ERV-K-Env exhibits limited recognition of its cognate epitope

Mob DNA. 2024 Oct 9;15(1):19. doi: 10.1186/s13100-024-00333-w.

Abstract

Transposable elements (TEs) are often expressed at higher levels in tumor cells than normal cells, implicating these genomic regions as an untapped pool of tumor-associated antigens. In ovarian cancer (OC), protein from the TE ERV-K is frequently expressed by tumor cells. Here we determined whether the targeting of previously identified epitope in the envelope gene (env) of ERV-K resulted in target antigen specificity against cancer cells. We found that transducing healthy donor T cells with an ERV-K-Env-specific T cell receptor construct resulted in antigen specificity only when co-cultured with HLA-A*03:01 B lymphoblastoid cells. Furthermore, in vitro priming of several healthy donors with this epitope of ERV-K-Env did not result in target antigen specificity. These data suggest that the T cell receptor is a poor candidate for targeting this specific ERV-K-Env epitope and has limited potential as a T cell therapy for OC.

Keywords: Endogenous retroviruses; Immunotherapy; T cell receptor; Transposable elements; Tumor immunology.