467 Engineered chimeric antigen receptor-expressing TILs for liver cancer treatment using a novel MSE-TIL platform
Year: 2024
Type: conference-abstract
Abstract: Background Tumor Infiltrating Lymphocytes (TILs) comprise various T cell clones with specificity towards tumor or viral antigens. TIL therapy has been approved for melanoma treatment with high-dose interleukin-2 (IL-2). However, the accessibility of TILs, the small fraction of antigen-specific T cells, limited persistence in vivo, exhausted phenotype, and toxicity of high-dose IL-2 infusion restrict its application to the treatment of other solid tumors. We developed multiple signaling elements (MSE)-TIL platform to expand and engineer TILs derived from liver cancer biopsies (figure 1). These TILs (MSE-TIL) showed increased memory T-cell percentage, improved proliferation capacity, and enhanced anti-tumor potential towards various liver cancer cells without IL-2 administration. Methods TILs were isolated from fresh or cryopreserved tumor biopsy samples and stimulated with anti-CD3/CD28 antibodies. Thereafter, TILs were modified by lentiviral transduction and further expanded with γ-irradiated feeder cells in an optimized rapid expansion process (REP) to induce memory CD8+ T cells. The final product was cryopreserved for storing and shipping. Phenotypic analyses were performed by flow cytometry. IFN-γ ELISA, RTCA Xcelligence, and IncuCyte were used to evaluate in vitro activation and cytotoxicity. Anti-tumor efficacy was further evaluated in immunocompromised xenograft models. Results The successful rate for MSE-TIL production from two tumor biopsies was ~ 95%, reaching 1011 TILs on day 26. Compared with traditional REP, the percentage of central memory CD8+ T cells was increased by 5-fold to promote persistent anti-tumor function in vitro (figure 2). TILs were additionally engineered with CAR recognizing tumor antigens including CD133 and CD44v6, cofactors such as membrane-bound interleukins and mitochondrial homeostasis regulators, to sustain their in vivo proliferation and long-term anti-tumor efficacy. The lentiviral transduction rate was stably maintained at over 30% (Day 28: CAR, 48.8 ± 9.1%; cofactor, 58.6 ± 12.6%) for up to 7 weeks ex vivo. MSE-TIL shows potent killing efficacy towards liver cancer cell lines. Moreover, MSE-TIL can accumulate in tumors and inhibit their growth without toxicity in an immunocompromised murine model (figure 3). Conclusions Engineered MSE-TILs demonstrated persistent therapeutic efficacy with no obvious toxicities in the mouse model, supporting its further clinical applications. Ethics Approval All animal studies were conducted by Biosyngen staff at Guangzhou Regenerative Medicine and Health, Guangdong Laboratory (GRMH-GDL) as approved by the Ruiye model animal (Guangzhou) Biotechnology Co., Ltd facility as approved by its Experimental Animal Care and Use Committee (approval No. RYEth20220516-1).
Authors: Mingyu Liu, Deping Han, Jean Paul Thiery, Xi Zhang
Language: English
Topic: CAR-T cell therapy research
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W4404065610