Tissue factor as a new target for CAR-NK cell immunotherapy of triple-negative breast cancer

Abstract

Triple-negative breast cancer (TNBC), representing ~15% of globally diagnosed breast cancer, is typically an incurable malignancy due to the lack of targetable surface targets for development of effective therapy. To address the unmet need for TNBC treatment, we recently determined that tissue factor (TF) is a useful surface target in 50-85% of patients with TNBC and developed a secondgeneration TF-targeting antibody-like immunoconjugate (called L-ICON) for preclinical treatment of TNBC. Using the chimeric antigen receptor (CAR) approach, here we develop and test TF-targeting CARengineered natural killer (TF-CAR-NK) cells that co-express CD16, the Fc receptor (FcγIII) to mediate antibody-dependent cellular toxicity (ADCC), for a preclinical assessment of immunotherapy of TNBC using TF-CAR-NK cell as single agent therapy and in combination with L-ICON. Our preclinical results demonstrate that TF-CAR-NK cells alone could kill TNBC cells and its efficacy was enhanced with L-ICON ADCC in vitro. Moreover, TF-CAR-NK cells were effective in vivo for the treatment of tnBc in cell lineand patient's tumor-derived xenograft mouse models. Thus, this study established the proof of concept of targeting TF as a new target in CAR-NK immunotherapy for effective treatment of TNBC and may warrant further preclinical study and potentially future investigation in TNBC patients.The adoptive transfer of chimeric antigen receptor (CAR)-expressing T and natural killer (NK) cells represents a novel cancer immunotherapy approach. The concept of the CAR is based upon the idea of expressing novel receptors on the T or NK cell surface that would enable the T and NK cell to identify corresponding antigens on the surface of a target cell. The basic CAR construct consists of an extracellular antigen-recognition domain, usually single-chain antibody variable fragments (scFv), attached to an extracellular spacer domain, a transmembrane domain of CD28 and a signaling cytoplasmic domain such as 4-1BB (CD137), OX40 (CD134), DAP10, ICOS and CD3zeta chain (CD3ζ). The most advanced application is the use of CAR-T cells targeting CD19, a surface antigen on B cell malignancies, which has demonstrated antitumor efficacy in patients with these cancers 1 . However, early-phase clinical trials of CAR T therapy also showed that this treatment is frequently associated with side effects 1 , some even causing life-threatening toxicity 2 , partly due to the fact that current CAR targets are expressed by both the malignant cells and normal cells, such as CD19, which is also expressed by normal B cells throughout the B cell lineage 1 . Also, one of the major challenges in CAR therapy is the heterogeneity of tumor antigens, for instance, antigen loss or low antigen density on the cancer cells 3 . To overcome these challenges, it would be ideal to develop CAR T or CAR NK cells that could target a surface molecule that is commonly yet selectively expressed by several major tumor compartments, including but not limited to, the cancer cell, cancer stem cell (CSC) and tum...

Current Targets and Bioconjugation Strategies in Photodynamic Diagnosis and Therapy of Cancer

“…The results showed that fVII-targeted PDT was effective and selective in eradicating angiogenic VECs without harming normal VECs (Figure 5d-f) [83]. This study demonstrated the feasibility of fVII-conjugated photosensitizer as a method of targeting angiogenic VECs for PDT, supporting TF as an angiogenic-specific target in the PDT treatment of cancer [83] and AMD [105], as well as in ICON, L-ICON, and CAR-NK immunotherapy of pathological angiogenesis-dependent diseases, notably cancer [65,84,85,96,103,107], AMD [95,97], and endometriosis [94,98].…”

“…The Hu laboratory further improved the original ICON (with full length fVII) to L-ICONs (for fVII light chain ICON, to reduce its molecular weight and deplete residual procoagulation activity), called L-ICON1 (second generation) [65] and L-ICON3 (third generation; patent pending), for the treatment of TNBC with enhanced efficacy and safety profiles. Later, TF was also validated as a target in other cancer indications in others works investigating antibody-drug conjugates (ADC) against TF [100][101][102] and in our own work of chimeric antigen receptor-modified NK (CAR-NK) cell therapy [103] under preclinical and clinical investigations.…”

“…Molecules 2020, 25, x FOR PEER REVIEW 7 of 27 VEGF and highly expressed TF (with peak expression at 4-6 h) [83], whereas unstimulated VECs were negative for TF expression and used as a normal VEC control [83]. The results showed that fVII-targeted PDT was effecdiseases, notably cancer [65,84,85,96,103,107], AMD [95,97], and endometriosis [94,98]. fVII-SnCe6 conjugates retain the binding activity and selectivity to angiogenic VECs (VEGF-stimulated HMVEC: human microvascular endothelial cells), while it has no binding to unstimulated HMVEC.…”

Engineering the Bridge between Innate and Adaptive Immunity for Cancer Immunotherapy: Focus on γδ T and NK Cells

“…Therefore, they obtained CD16 + TF-CAR-NK cells, capable of mediating IgG1 and IgG3-mediated ADCC. The limitation of such strategy was the low transduction efficiency (~10%) [ 145 ]. The two-step transduction approach provided superior transduction efficiency (>90%) when used to generate ErbB2 and CD33 CAR-NK cells [ 129 ].…”

Adoptive Cell Therapy in Breast Cancer: A Current Perspective of Next-Generation Medicine

“…Encouraging results have been reported in a phase I/IIa trial using cord blood-derived CAR-NK cells targeting CD19 in patients with relapsed or refractory non-Hodgkin's lymphoma and chronic lymphocytic leukemia, with up to 64% of patients achieving a complete response (93). In BC, tissue factor (TF) was recently described by Hu as a novel and common yet selective molecule on TNBC, whose targeting by TF-CAR NK cells resulted in an increased cytotoxicity against TNBC cell lines and was effective and safe for the treatment of TNBC in an orthotopic mouse model (94). Chen et al recapitulated these findings when investigating the effect of EGFR-CAR NK cells in TBNC cell lines and in mice preinoculated with brain metastases (95).…”