Antigen-dependent IL-12 signaling in CAR T cells promotes regional to systemic disease targeting.
Publication Year:
2023
PubMed ID:
37550294
Funding Grants:
Public Summary:
CAR T cell therapy often struggles to effectively reach solid tumors in the body, remain there, and fight the tumors. However, with advanced engineering, these issues can be improved. This study focuses on CAR T cells designed to target a protein called tumor-associated glycoprotein-72 (TAG72), using specific components (CD28 and 4-1BB) to boost their ability to attack tumors and produce an immune response molecule called IFNγ. This IFNγ production, aided by IL-12 signaling, is crucial for killing tumor cells. By engineering CAR T cells to include a specially designed membrane-bound IL-12 (mbIL12), these cells are more effective at multiplying in response to the tumor and repeatedly killing tumor cells in lab tests. They also show strong effectiveness in living models of human ovarian cancer. Delivering these mbIL12-engineered CAR T cells directly to the tumor area in mice resulted in long-lasting anti-tumor responses both in the targeted area and throughout the body. The safety and effectiveness of these engineered CAR T cells were also confirmed in mice with functioning immune systems, showing that they can positively impact the tumor's immune environment. Overall, this study presents a practical approach to enhance the effectiveness of CAR T cells delivered directly to the tumor, by engineering them with immune-boosting cytokines to target both local and widespread disease.
Scientific Abstract:
Chimeric antigen receptor (CAR) T cell therapeutic responses are hampered by limited T cell trafficking, persistence, and durable anti-tumor activity in solid tumors. However, these challenges can be largely overcome by relatively unconstrained synthetic engineering strategies. Here, we describe CAR T cells targeting tumor-associated glycoprotein-72 (TAG72), utilizing the CD28 transmembrane domain upstream of the 4-1BB co-stimulatory domain as a driver of potent anti-tumor activity and IFNgamma secretion. CAR T cell-mediated IFNgamma production facilitated by IL-12 signaling is required for tumor cell killing, which is recapitulated by engineering an optimized membrane-bound IL-12 (mbIL12) molecule in CAR T cells. These T cells show improved antigen-dependent T cell proliferation and recursive tumor cell killing in vitro, with robust in vivo efficacy in human ovarian cancer xenograft models. Locoregional administration of mbIL12-engineered CAR T cells promotes durable anti-tumor responses against both regional and systemic disease in mice. Safety and efficacy of mbIL12-engineered CAR T cells is demonstrated using an immunocompetent mouse model, with beneficial effects on the immunosuppressive tumor microenvironment. Collectively, our study features a clinically-applicable strategy to improve the efficacy of locoregionally-delivered CAR T cells engineered with antigen-dependent immune-modulating cytokines in targeting regional and systemic disease.