Targeting CEA in metastatic triple negative breast cancer with image-guided radiation followed by Fab-mediated chimeric antigen receptor (CAR) T-cell therapy.

Although CAR-T cell therapy has limited efficacy against solid tumors, it has been hypothesized that prior treatment with Image-Guided Radiation Therapy (IGRT) would increase CAR-T cell tumor infiltration, leading to improved antigen specific expansion of CAR-T cells. To test this hypothesis in a metastatic triple negative breast cancer (TNBC) model, we engineered two anti-CEA single-chain Fab (scFab) CAR-T cells with signaling domains from CD28zeta and 4-1BBzeta, and tested them in vitro and in vivo. The anti-CEA scFab CAR-T cells generated from three different human donors demonstrated robust in vitro expression, expansion, and lysis of only CEA-positive TNBC cells, with the CD28z-CAR-T cells showing the highest cytotoxicity. IFN-γ and granzyme B release assays revealed significantly higher IFN-γ production at a 4:1 effector-to-target (E:T) ratio in CD28z-CAR-T cells compared to 4-1BBz-CAR-T cells. Treatment of CEA-positive TNBC MDA-MB231 xenografts in the mammary fat pads of NSG mice, that produced spontaneous lung metastases over time, resulted in significant tumor growth reduction compared to either therapy alone (p<0.01). Immunohistochemical (IHC) analysis revealed that only combined IGRT and CAR-T therapy resulted in the elimination of lung metastases. These findings demonstrate that the combination of IGRT and anti-CEA scFab CAR-T therapy induces a strong antitumor response, effectively targeting both the primary tumor and distant metastatic lesions in the lungs, thus demonstrating that IGRT enhances CAR-T cell infiltration, persistence, and overall efficacy within both primary and metastatic lesions.

Aniogo E ，Kujawski M ，Awuah D ，Cha SE ，Espinosa R ，Hui S ，Ghimire H ，Yazaki PJ ，Brown CE ，Wang X ，Shively JE ... -  《Frontiers in Immunology》

CAR T Cells Targeting the Tumor MUC1 Glycoprotein Reduce Triple-Negative Breast Cancer Growth.

Zhou R ，Yazdanifar M ，Roy LD ，Whilding LM ，Gavrill A ，Maher J ，Mukherjee P ... -  《Frontiers in Immunology》

A novel AXL chimeric antigen receptor endows T cells with anti-tumor effects against triple negative breast cancers.

Identifying targets for chimeric antigen receptor-modulated T lymphocyte (CAR-T) therapy against solid tumors is an urgent problem to solve. In this study, we showed for the first time that the receptor tyrosine kinase, AXL, is overexpressed in various tumor cell lines and patient tumor tissues including triple negative breast cancer (TNBC) cell lines and patient samples, making AXL a potent novel target for cancer therapy, specifically for TNBC treatment. We also engineered T cells with a CAR consisting of a novel single-chain variable fragment against AXL and revealed its antigen-specific cytotoxicity and ability to release cytokines in a TNBC cell line and other AXL-positive tumors in vitro. Furthermore, AXL-CAR-T cells displayed a significant anti-tumor effect and in vivo persistence in a TNBC xenograft model. Taken together, our findings indicate that AXL-CAR-T cells can represent a promising therapeutic strategy against TNBC.

Wei J ，Sun H ，Zhang A ，Wu X ，Li Y ，Liu J ，Duan Y ，Xiao F ，Wang H ，Lv M ，Wang L ，Wu C ... -  《-》

Significantly increased anti-tumor activity of carcinoembryonic antigen-specific chimeric antigen receptor T cells in combination with recombinant human IL-12.

Chimeric antigen receptor T cells (CAR-T cells) have been successfully used in treatments of hematological tumors, however, their anti-tumor activity in solid tumor treatments was limited. As IL-12 increases T-cell immune functions, we designed carcinoembryonic antigen (CEA) specific CAR-T (CEA-CAR-T) cells and, for the first time, used them in combination with recombinant human IL-12 (rhIL-12) to treat several types of solid tumors. In vitro anti-tumor activity of CEA-CAR-T cells in combination with rhIL-12 was confirmed by evaluation of CEA-CAR-T cell activation, proliferation, and cytotoxicity after co-incubation with CEA-positive or CEA-negative human tumor cells. In vivo anti-tumor activity of CEA-CAR-T cells in combination with rhIL-12 was confirmed in a xenograft model in nude mice for treatments of several types of solid tumors. In vitro experiments confirmed that rhIL-12 significantly increased the activation, proliferation, and cytotoxicity of CEA-CAR-T cells. Similarly, in vivo experiments found that CEA-CAR-T cells in combination with rhIL-12 had significantly enhanced anti-tumor activity than CEA-CAR-T cells in growth inhibition of newly colonized colorectal cancer cell HT-29, pancreatic cancer cell AsPC-1, and gastric cancer cell MGC803. These works confirmed that simultaneous use of cytokines, for example, rhIL-12, can increase the anti-tumor activity of CAR-T cells, especially for treatments of several types of solid tumors.

Chi X ，Yang P ，Zhang E ，Gu J ，Xu H ，Li M ，Gao X ，Li X ，Zhang Y ，Xu H ，Hu J ... -  《Cancer Medicine》

Intercellular Adhesion Molecule-1 as Target for CAR-T-Cell Therapy of Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) comprises lethal malignancies with limited treatment options. Chimeric antigen receptor T (CAR-T) cell therapy is an effective immunotherapeutic strategy that has demonstrated unprecedented efficacy in the treatment of hematological malignancies but has shown limited success in the management of some solid tumors. Many malignant tumors are related to increased expression of intercellular adhesion molecule-1 (ICAM1), providing a rationale for ICAM1-specific immunotherapies for the treatment of cancer. Here, we validated the expression of ICAM1 in TNBC tissues. Subsequently, we generated a phage-displayed single-chain variable fragment (scFv) library using splenocytes from ICAM1-immunized mice and selected a novel ICAM1-specific scFv, mG2-scFv. Using mG2-scFv as the extracellular antigen binding domain, we constructed ICAM1-specific CAR-T cells and demonstrated the robust and specific killing of TNBC cell lines in vitro. Most importantly, in the TNBC mouse model, ICAM1-specific CAR-T cells significantly reduced the growth of the TNBC tumor, resulting in long-term remission and improved survival. Together, these results indicated that ICAM1-specific CAR-T cells have high therapeutic potential against ICAM1-positive TNBC tumors.

Wei H ，Wang Z ，Kuang Y ，Wu Z ，Zhao S ，Zhang Z ，Li H ，Zheng M ，Zhang N ，Long C ，Guo W ，Nie C ，Yang H ，Tong A ... -  《Frontiers in Immunology》