Induction of Neoantigen-Specific Cytotoxic T Cells and Construction of T-cell Receptor–Engineered T Cells for Ovarian Cancer

Abstract

To prepare Translational relevanceAdoptive T cell therapy with neoantigen-specific T cell receptor (TCR)-engineered T cells is considered as a promising novel immunotherapy strategy. It takes four steps to prepare; (1) prediction of neoantigen epitopes, (2) neoantigen peptides synthesis, (3) identification of neoantigen-specific TCR and (4) production of virus vector to express TCR. Among them, the most challenging part is identification of neoantigen-specific TCRs. Our protocol required only two weeks from stimulation of T cells with peptides to the identification of neoantigen-specific TCRs. We conducted a pilot study to validate our time-efficient protocol in solid cancers with relatively lower mutational loads such as ovarian cancer. We successfully induced neoantigen-specific T cells against three neoantigens and established corresponding TCR-engineered T cells. One case of neoantigen-specific TCR-engineered T cells showed cross-reactivity against the corresponding wild-type peptide. These results give an important insight into the clinical application of adoptive T cell therapy with neoantigen-specific TCR-engineered T cells.Research. Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited. Author Manuscript Published OnlineFirst on May 2, 2018; DOI: 10.1158/1078-0432.CCR-18-0142 4 ABSTRACTPurpose: Current evolution of cancer immunotherapies, such as immune checkpoint blockade, has implicated neoantigens as major targets of anti-cancer cytotoxic T cells. Adoptive T cell therapy with neoantigen-specific T cell receptor (TCR)-engineered T cells would be an attractive therapeutic option for advanced cancers where the host antitumor immune function is strongly inhibited. We previously developed a rapid and efficient pipeline for production of neoantigen-specific TCR-engineered T cells using peripheral blood from an HLA-matched healthy donor. Our protocol required only two weeks from stimulation of T cells with neoantigen-loaded dendritic cells to the identification of neoantigen-specific TCRs. We conducted the pilot study to validate our protocol. Experimental Design: We used tumors from 7 ovarian cancer patients to validate our protocol.Results: We chose 14 candidate neoantigens from 7 ovarian tumors (1-3 candidates for each patient), and then successfully induced 3 neoantigen-specific T cells from one healthy donor and identified their TCR sequences. Moreover, we validated functional activity of the three identified TCRs by generating TCR-engineered T cells which recognized the corresponding neoantigens and showed cytotoxic activity in an antigendose-dependent manner. However, one case of neoantigen-specific TCR-engineered T cells showed cross-reactivity against the corresponding wild-type peptide. Conclusion/discussions: This pilot study demonstrated the feasibility of our efficient process from identification of neoantigen to production of the neoantigen-targeting cytotoxic TCR-engineered T cells for ovarian cancer and revealed the importance of careful validati...

TCR sequencing analysis of cancer tissues and tumor draining lymph nodes in colorectal cancer patients

“…As another promising immunotherapy to enhance the host immune system, researchers including us have been working on adoptive T cell therapy with TCR-engineered T cells. 6,[33][34][35][36][37][38] Rapoport et al reported the clinical benefit of NY-ESO-1-specific TCR-engineered T cell transfer therapy for multiple myeloma patients. Clinical responses observed in this trial was impressively high as 80% (16 of 20 patients) with a median progression-free survival of 19.1 months.…”

T-cells “à la CAR-T(e)” – Genetically engineering T-cell response against cancer

“…Furthermore, in order to reduce the potential immunogenicity of murine constant regions [18], it was possible to identify key amino acid residues that mediate the preferential pairing and to use minimally murinized TCR chains that retained most of the activity displayed by the fully murinized one [42,43]. The use of murinized receptor was successfully extended to other TCRs [44][45][46]. Another possibility to promote chain pairing we and others explored, was to engineer an additional di-sulfide bond in the constant region of the TCR inserted chains [47,48].…”

Significant differences in T cell receptor repertoires in lung adenocarcinomas with and without epidermal growth factor receptor mutations

“…The progress in analyzing T cell receptor (TCR) repertoires in cancer tissues made it possible to evaluate the diversity of T cell clonotypes and the extent of clonal T cell expansion, and to characterize neoantigen‐specific TCR . Detailed information on the tumor microenvironment may serve as a predictive marker for immunomodulatory therapies and may also be useful for development of new treatment strategies, including personalized T cell‐mediated cancer immunotherapy and neoantigen vaccine therapy . TCR repertoire analyses could be used to monitor the dynamics of T cell clonality and the individual tumor‐reactive T cell clones in cancer patients treated with ICI .…”