作者: Henssen, Anton G ; Schwiebert, Silke ; Blankenstein, Thomas ; Lodrini, Marco ; Eilers, Martin ; Höpken, Uta E ; Wicha, Sebastian G ; Fuchs, Steffen ; Klaus, Anika ; Westermann, Frank ; Straka, Teresa ; Grunewald, Laura ; Vitali, Alice ; Helmsauer, Konstantin ; Künkele, Annette ; Astrahantseff, Kathy ; Anders, Kathleen ; Schulte, Johannes H ; Andersch, Lena ; Büchel, Gabriele ; Caramel, Carlotta ; Eggert, Angelika ; Hertwig, Falk

Current treatment protocols have limited success against MYCN-amplified neuroblastoma. Adoptive T cell therapy presents an innovative strategy to improve cure rates. However, L1CAM-targeting CAR T cells achieved only limited response against refractory/relapsed neuroblastoma so far. We investigated how oncogenic MYCN levels influence tumor cell response to CAR T cells, as one possible factor limiting clinical success. A MYCN-inducible neuroblastoma cell model was created. L1CAM-CAR T cell effector function was assessed (activation markers, cytokine release, tumor cytotoxicity) after coculture with the model or MYCN-amplified neuroblastoma cell lines. RNA sequencing datasets characterizing the model were compared to publicly available RNA/proteomic datasets. MYCN-directed L1CAM regulation was explored using public ChIP-sequencing datasets. Synergism between CAR T cells and the indirect MYCN inhibitor, MLN8237, was assessed in vitro using the Bliss model and in vivo in an immunocompromised mouse model. Inducing high MYCN levels in the neuroblastoma cell model reduced L1CAM expression and, consequently, L1CAM-CAR T cell effector function in vitro. Primary neuroblastomas possessing high MYCN levels expressed lower levels of both the L1CAM transcript and L1CAM tumor antigen. MLN8237 treatment restored L1CAM tumor expression and L1CAM-CAR T cell effector function. Combining MLN8237 and L1CAM-CAR T cell treatment synergistically enhanced MYCN-overexpressing tumor cytotoxicity in vitro and in vivo concomitant with severe in vivo toxicity. We identify target antigen downregulation as source of resistance against L1CAM-CAR T cells in MYCN-driven neuroblastoma cells. These data suggest that L1CAM-CAR T cell therapy combined with pharmacological MYCN inhibition may benefit patients with MYCN-amplified neuroblastoma.

2020-07-01·Molecular Carcinogenesis

Central memory phenotype drives success of checkpoint inhibition in combination with CAR T cells

Article

作者: Grunewald, Laura ; Deubzer, Hedwig E. ; Ochsenreither, Sebastian ; Schulte, Johannes H. ; Zirngibl, Felix ; Schwiebert, Silke ; Astrahantseff, Kathy ; Künkele, Annette ; Winkler, Annika ; Wagner, Dimitrios L. ; Klaus, Anika ; Toews, Karin ; Eggert, Angelika ; Ali, Solin ; Henssen, Anton G.

AbstractThe immunosuppressive microenvironment in solid tumors is thought to form a barrier to the entry and efficacy of cell‐based therapies such as chimeric antigen receptor (CAR) T cells. Combining CAR T cell therapy with checkpoint inhibitors has been demonstrated to oppose immune escape mechanisms in solid tumors and augment antitumor efficacy. We evaluated PD‐1/PD‐L1 signaling capacity and the impact of an inhibitor of this checkpoint axis in an in vitro system for cancer cell challenge, the coculture of L1CAM‐specific CAR T cells with neuroblastoma cell lines. Fluorescence‐activated cell sorting‐based analyses and luciferase reporter assays were used to assess PD‐1/PD‐L1 expression on CAR T and tumor cells as well as CAR T cell ability to kill neuroblastoma cells. Coculturing neuroblastoma cell lines with L1CAM‐CAR T cells upregulated PD‐L1 expression on neuroblastoma cells, confirming adaptive immune resistance. Exposure to neuroblastoma cells also upregulated the expression of the PD‐1/PD‐L1 axis in CAR T cells. The checkpoint inhibitor, nivolumab, enhanced L1CAM‐CAR T cell‐directed killing. However, nivolumab‐enhanced L1CAM‐CAR T cell killing did not strictly correlate with PD‐L1 expression on neuroblastoma cells. In fact, checkpoint inhibitor success relied on strong PD‐1/PD‐L1 axis expression in the CAR T cells, which in turn depended on costimulatory domains within the CAR construct, and more importantly, on the subset of T cells selected for CAR T cell generation. Thus, T cell subset selection for CAR T cell generation and CAR T cell prescreening for PD‐1/PD‐L1 expression could help determine when combination therapy with checkpoint inhibitors could improve treatment efficacy.

100 项与 L1CAM-directed CAR T(University of Bern) 相关的药物交易

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