A Novel Cell-based Luciferase Reporter Platform for the Development and Characterization of T-Cell Redirecting Therapies and Vaccine Development. Issue 3 (20th April 2023)

• Record Type: Journal Article
• Authors: Grailer, Jamison; Cheng, Zhijie Jey; Hartnett, Jim; Slater, Michael; Fan, Frank; Cong, Mei
• Is Part Of: Journal of immunotherapy. Volume 46:Issue 3(2023)
• Page Start: 96
• Page End: 106
• Publication Date: 2023-04-20
• Subjects: T cell -- TCR-T -- vaccine -- cell-based bioassay -- reporter bioassay; Immunotherapy -- Periodicals; Immunotherapy -- Periodicals; Neoplasms -- therapy -- Periodicals; Electronic journals; Electronic journals; 615.37
• DOI: 10.1097/CJI.0000000000000453
• Languages: English
• ISSNs: 1524-9557

Abstract

Abstract : T-cell immunotherapies are promising strategies to generate T-cell responses towards tumor-derived or pathogen-derived antigens. Adoptive transfer of T cells genetically modified to express antigen receptor transgenes has shown promise for the treatment of cancer. However, the development of T-cell redirecting therapies relies on the use of primary immune cells and is hampered by the lack of easy-to-use model systems and sensitive readouts to facilitate candidate screening and development. Particularly, testing T-cell receptor (TCR)-specific responses in primary T cells and immortalized T cells is confounded by the presence of endogenous TCR expression which results in mixed alpha/beta TCR pairings and compresses assay readouts. Herein, we describe the development of a novel cell-based TCR knockout (TCR-KO) reporter assay platform for the development and characterization of T-cell redirecting therapies. CRISPR/Cas9 was used to knockout the endogenous TCR chains in Jurkat cells stably expressing a human interleukin-2 promoter-driven luciferase reporter gene to measure TCR signaling. Reintroduction of a transgenic TCR into the TCR-KO reporter cells results in robust antigen-specific reporter activation compared with parental reporter cells. The further development of CD4/CD8 double-positive and double-negative versions enabled low-avidity and high-avidity TCR screening with or without major histocompatibility complex bias. Furthermore, stable TCR-expressing reporter cells generated from TCR-KO reporter cells exhibit sufficient sensitivity to probe in vitro T-cell immunogenicity of protein and nucleic acid-based vaccines. Therefore, our data demonstrated that TCR-KO reporter cells can be a useful tool for the discovery, characterization, and deployment of T-cell immunotherapy.