Antigen-dependent IL-12 signaling in CAR T cells promotes regional to systemic disease targeting

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 IFNγ secretion. CAR T cell-mediated IFNγ 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.

The safety and efficacy of systemic delivery of a new liver-de-targeted TGFβ signaling inhibiting adenovirus in an immunocompetent triple negative mouse mammary tumor model

“…To be noted, we also found that mHAdLyp.sT alone can increase serum levels of GM-CSF and some critical anti-tumor Th1 cytokines such as IL-12 and IFN-γ, and boost the percentage of cytotoxic CD8 + T cells in the spleen and tumor. Especially for IL-12 and IFN-γ, both of which are major determinants of CAR T-cell-based antitumor activity [ 39 , 40 ]. Thus, these results suggest that mHAdLyp.sT may be able to increase the efficacy of adoptively transferred TCR-transduced or CAR-transduced T cells against metastatic cancers as well, by inducing tumor eradication rather than simply slowing the growth.…”

Current and future immunotherapeutic approaches in pancreatic cancer treatment

“…The findings illustrated that the incorporation of rhIL-12 alongside anti-CEA CAR T cells notably augmented their capacity to suppress the proliferation of pancreatic tumor cells when compared to solely utilizing CEA CAR T-cell treatment [ 294 ]. Regarding the central role of IL-12 in CAR T cells, a study has proven that membrane-bound IL-12 in CAR T cells targeting TAG72 promotes anti-tumor responses against human ovarian cancer xenograft models [ 295 ]. However, there is a need to apply this approach in PDAC that has not been met.…”

Regional and intratumoral adoptive T-cell therapy

“… 43 Systemic immune responses in non-treated lesions were also observed in several preclinical studies after intratumor T-cell delivery. 44 , 45 , 46 Interestingly, rechallenged cured mice were also able to control both antigen-positive tumor growth and antigen-negative tumors after locoregional adoptive transfer of B7-H3-specific CAR-T cells, 47 suggesting that regional ACT may induce antigen-spreading and long-term systemic immune responses against cancer recurrence.…”

“…The pattern of spread of these types of cancers over a serosa surface may lend them to regional delivery. Intracavitary delivery of engineered TCR-transgenic 53 and CAR-T cells 44 promoted eradication of peritoneal metastases in ovarian tumor mouse models. An enhanced T-cell persistence after intracavitary delivery compared with the i.v.…”