BCL6 overexpression in CD4(+) T cells induces Tfh-like transdifferentiation and enhances antitumor efficiency of CAR-T therapy in pancreatic cancer.

PDAC is a typical "cold tumor" characterized by low immune cell infiltration and a suppressive immune microenvironment. We previously observed the existence of a rare group of follicular helper T cells (Tfh) that could enhance antitumor immune responses by recruiting other immune cells in PDAC. In this study, we ectopically expressed BCL6 in CD4+ T cells, and successfully induced Tfh-like transdifferentiation in vitro. This strategy provided abundant Tfh-like cells (iTfhs) that can recruit CD8+ T cells like endogenous Tfhs. Subsequently, Chimeric Antigen Receptors (CARs) against both MSL (Mesothelin) and EPHA2 (Ephrin receptor A2) were used to modify iTfh cells, and the CAR-iTfh cells significantly improved infiltration and antitumor cytotoxicity of co-cultured CD8+ T cells. After that, combinatory administration of CAR-iTfh & CAR-CD8 T cell therapy displayed a better effect in repressing the PDAC tumors in xenograft mouse models, compared to conventional CAR-CD4 & CAR-CD8 combinations, and the models received the CAR-iTfh & CAR-CD8 T cells displayed a significantly improved survival rate. Our study revealed the plasticity of Thelper differentiation, expanded the source of Tfh-like cells for cell therapy, and demonstrated a novel and potentially more efficient cellular composition for CAR-T therapy.

Lin X ，Dai Z ，Tasiheng Y ，Zhang R ，Wang R ，Dong J ，Chen Y ，Ma M ，Zou X ，Yan Y ，Wang X ，Yu X ，Cheng H ，Liu C ... -  《-》

Mesothelin CAR T Cells Secreting Anti-FAP/Anti-CD3 Molecules Efficiently Target Pancreatic Adenocarcinoma and its Stroma.

Targeting solid tumors with chimeric antigen receptor (CAR) T cells remains challenging due to heterogenous target antigen expression, antigen escape, and the immunosuppressive tumor microenvironment (TME). Pancreatic cancer is characterized by a thick stroma generated by cancer-associated fibroblasts (CAF), which may contribute to the limited efficacy of mesothelin-directed CAR T cells in early-phase clinical trials. To provide a more favorable TME for CAR T cells to target pancreatic ductal adenocarcinoma (PDAC), we generated T cells with an antimesothelin CAR and a secreted T-cell-engaging molecule (TEAM) that targets CAF through fibroblast activation protein (FAP) and engages T cells through CD3 (termed mesoFAP CAR-TEAM cells). Using a suite of in vitro, in vivo, and ex vivo patient-derived models containing cancer cells and CAF, we examined the ability of mesoFAP CAR-TEAM cells to target PDAC cells and CAF within the TME. We developed and used patient-derived ex vivo models, including patient-derived organoids with patient-matched CAF and patient-derived organotypic tumor spheroids. We demonstrated specific and significant binding of the TEAM to its respective antigens (CD3 and FAP) when released from mesothelin-targeting CAR T cells, leading to T-cell activation and cytotoxicity of the target cell. MesoFAP CAR-TEAM cells were superior in eliminating PDAC and CAF compared with T cells engineered to target either antigen alone in our ex vivo patient-derived models and in mouse models of PDAC with primary or metastatic liver tumors. CAR-TEAM cells enable modification of tumor stroma, leading to increased elimination of PDAC tumors. This approach represents a promising treatment option for pancreatic cancer.

Wehrli M ，Guinn S ，Birocchi F ，Kuo A ，Sun Y ，Larson RC ，Almazan AJ ，Scarfò I ，Bouffard AA ，Bailey SR ，Anekal PV ，Montero Llopis P ，Nieman LT ，Song Y ，Xu KH ，Berger TR ，Kann MC ，Leick MB ，Silva H ，Salas-Benito D ，Kienka T ，Grauwet K ，Armstrong TD ，Zhang R ，Zhu Q ，Fu J ，Schmidts A ，Korell F ，Jan M ，Choi BD ，Liss AS ，Boland GM ，Ting DT ，Burkhart RA ，Jenkins RW ，Zheng L ，Jaffee EM ，Zimmerman JW ，Maus MV ... -  《-》

Proton radiation boosts the efficacy of mesothelin-targeting chimeric antigen receptor T cell therapy in pancreatic cancer.

Amit U ，Uslu U ，Verginadis II ，Kim MM ，Motlagh SAO ，Diffenderfer ES ，Assenmacher CA ，Bicher S ，Atoche SJ ，Ben-Josef E ，Young RM ，June CH ，Koumenis C ... -  《-》

Pancreatic cancer therapy with combined mesothelin-redirected chimeric antigen receptor T cells and cytokine-armed oncolytic adenoviruses.

Watanabe K ，Luo Y ，Da T ，Guedan S ，Ruella M ，Scholler J ，Keith B ，Young RM ，Engels B ，Sorsa S ，Siurala M ，Havunen R ，Tähtinen S ，Hemminki A ，June CH ... -  《JCI Insight》

Simultaneous targeting of Tim3 and A2a receptors modulates MSLN-CAR T cell antitumor function in a human cervical tumor xenograft model.

Chimeric antigen receptor (CAR) T cell therapy has transformed the treatment of hematological malignancies. However, its efficacy in solid tumors is limited by the immunosuppressive tumor microenvironment that compromises CAR T cell antitumor function in clinical settings. To overcome this challenge, researchers have investigated the potential of inhibiting specific immune checkpoint receptors, including A2aR (Adenosine A2 Receptor) and Tim3 (T cell immunoglobulin and mucin domain-containing protein 3), to enhance CAR T cell function. In this study, we evaluated the impact of genetic targeting of Tim3 and A2a receptors on the antitumor function of human mesothelin-specific CAR T cells (MSLN-CAR) in vitro and in vivo. Second-generation anti-mesothelin CAR T cells were produced using standard cellular and molecular techniques. A2aR-knockdown and/or Tim3- knockdown anti-mesothelin-CAR T cells were generated using shRNA-mediated gene silencing. The antitumor function of CAR T cells was evaluated by measuring cytokine production, proliferation, and cytotoxicity in vitro through coculture with cervical cancer cells (HeLa cell line). To evaluate in vivo antitumor efficacy of manufactured CAR T cells, tumor growth and mouse survival were monitored in a human cervical cancer xenograft model. In vitro experiments demonstrated that knockdown of A2aR alone or in combination with Tim3 significantly improved CAR T cell proliferation, cytokine production, and cytotoxicity in presence of tumor cells in an antigen-specific manner. Furthermore, in the humanized xenograft model, both double knockdown CAR T cells and control CAR T cells could effectively control tumor growth. However, single knockdown CAR T cells were associated with reduced survival in mice. These findings highlight the potential of concomitant genetic targeting of Tim3 and A2a receptors to augment the efficacy of CAR T cell therapy in solid tumors. Nevertheless, caution should be exercised in light of our observation of decreased survival in mice treated with single knockdown MSLN-CAR T cells, emphasizing the need for careful efficacy considerations.

Soltantoyeh T ，Akbari B ，Shahosseini Z ，Mirzaei HR ，Hadjati J ... -  《Frontiers in Immunology》