lin li, PhD Candidate : No financial relationships to disclose
Introduction/Rationale: Chimeric antigen receptor (CAR) T cell therapy in solid tumors is limited by the immunosuppressive tumor microenvironment (TME). Since we have identified T-bet as a strong anti-tumor candidate, we thought to explore new therapies against NSCLC by developing next-generation CAR T cells and patient-derived lung cancer organoids (PDOs) as a clinically relevant preclinical platform for evaluating CAR T cell antitumor efficacy.
Methods: To explore strategies that improve CAR T cell efficacy and persistence, we first characterized T cells in the lung tumor environment by flow cytometry. Next, we cultured PBMCs and purified CD3+ T cells from patients with NSCLC with IL-2 or IL-2+ IL-12 to assess the changes in T-bet expression in vitro. We thus engineered B7-H3 (CD276) directed CAR T cells co-expressing either IL-12 or the transcription factor T-bet (TBX21). Simultaneously, patient-derived organoids were established from lung cancer tissues to preserve tumor heterogeneity and architecture as a clinically relevant platform for CAR T cell antitumor efficacy evaluation.
Results: Here we found low levels of Th1 T-bet + T cells in patients with NSCLC as compared to healthy controls. Moreover, in PBMCs under IL-2+ IL-12 stimulation, we found a significant expansion of CD3+CD4+ T-bet+ T cells. Preliminary data indicate that IL-12–armored CAR T cells exhibited the highest anti-tumor effect against the lung adenocarcinoma cell line A549, but raised concerns about systemic toxicity as confirmed in in vitro observations. In contrast, T-bet–modified CAR T cells displayed stronger CAR T cell survival and expansion associated with significant antitumor response.
Conclusion: This study leverages PDOs as a clinically relevant preclinical model to optimize CAR T design and supports T-bet as a promising axis for developing safer and more durable next generation CAR T therapies against NSCLC.
