An anti-mesothelin targeting antibody drug conjugate induces pyroptosis and ignites antitumor immunity in mouse models of cancer

Abstract

BackgroundEmerging evidence suggests that the mechanism of chemotherapy-induced cell death may influence the antitumor immune response in patients with cancer. Unlike immunologically silent apoptosis, pyroptosis is a lytic and inflammatory form of programmed cell death characterized by pore formation in the cell membrane and release of proinflammatory factors. Gasdermin E (GSDME) has recently gained attention after cleavage of GSDME by certain chemotherapeutics has been shown to elicit pyroptosis. This study investigated the immunomodulatory effects of a mesothelin-targeting antibody drug conjugate (ADC) in mouse models of breast and colon cancer.MethodsThe antitumor effects of the ADC were studied in EMT6 breast cancer and CT26 colon cancer syngeneic mouse models. The immunomodulatory effects of the ADC were assessed by analysis of tumor-infiltrating immune cells using flow cytometry. ADC mechanism of action was evaluated by morphology, biological assays, ADC-mediated cleavage of key effector proteins, and CRISPR/Cas9-mediated knockout (KO). Finally, the antitumor effect of ADC and Fms-like tyrosine kinase-3 ligand (Flt3L) combination therapy was evaluated in tumors expressing GSDME as well as in GSDME-silenced tumors.ResultsThe data demonstrated that the ADC controlled tumor growth and stimulated anticancer immune responses. Investigation of the mechanism of action revealed that tubulysin, the cytotoxic payload of the ADC, induced cleavage of GSDME and elicited pyroptotic cell death in GSDME-expressing cells. Using GSDME KO, we showed that GSDME expression is critical for the effectiveness of the ADC as a monotherapy. Combining the ADC with Flt3L, a cytokine that expands dendritic cells in both lymphoid and non-lymphoid tissues, restored control of GSDME KO tumors.ConclusionsTogether, these results show for the first time that tubulysin and a tubulysin containing ADC can elicit pyroptosis, and that this fiery cell death is critical for antitumor immunity and therapeutic response.

Development and validation of a pyroptosis-related prognostic signature associated with osteosarcoma metastasis and immune infiltration

“…Previous studies have demonstrated that the aDC controlled tumor growth and stimulated anticancer immune responses. [ 27 ] Beneficial M2-to-M1 polarization of macrophages could induce pyroptosis to enhance antitumor immunity. [ 28 ] At present, our research further fills the gap of a prediction model based on pyroptosis-related genes.…”

The gasdermin family: emerging therapeutic targets in diseases

“… 187 Inducing tumor pyroptosis to promote anti-tumor immunity is a potential cancer treatment strategy. Various drugs for cancer treatment act in part through caspase-3/GSDME-mediated tumor cell pyroptosis, including triptolide, 414 mesothelin-targeting antibody-drug conjugate, 415 apoptin, 416 platinum-based drugs, 417 , 418 tetraarsenic hexoxide, 419 and alantolactone. 420 GSDME knockout or knockdown may mitigate the anti-tumor potency of these agents.…”

The multifaceted roles of GSDME-mediated pyroptosis in cancer: therapeutic strategies and persisting obstacles

“…It has been confirmed that GSDME-mediated pyroptosis plays a crucial role in anti-programmed cell death protein 1 (PD-1) therapy, antibody-drug conjugates (ADCs) therapy, and chimeric antigen receptor T cells (CAR-T cells) therapy [ 160 – 162 ] (Fig. 5 ).…”

“…Recently, research has revealed that ADC treatment stimulates pyroptotic cell death and induces anti-tumor immunity in GSDME-expressing carcinomas [ 172 ]. The binding of ADC to dendritic cells modulates Fms-like tyrosine kinase-3 ligand (Flt3L) restores anti-tumor immunity in GSDME-silenced tumors and can potentially improve clinical outcomes [ 162 ]. In mouse models of colon and breast cancer, tubulysin, a microtubule depolymerizing agent, can trigger tumor cell death by targeting the GSDME-mediated pyroptotic pathway and modulating tumor sensitivity to ADC treatment [ 162 ].…”