Abstract 4559: Evaluation of the chemotherapy potential to improve the anti-cancer efficacy of PD-L1 inhibition using novel 3D microfluidic co-culture platform

Abstract

Immunotherapy is now recognized as a powerful therapeutic approach to treat and cure cancer. However, the objective response rates for most solid tumors are low (below 30%). Accumulating evidence has shown that chemotherapy can increase the efficacy of immune checkpoint blockade and improve cancer outcomes. We have investigated if chemotherapy can modulate anti-PDL1 enhanced T cell cytotoxicity in breast cancer using novel in vitro 3D co-culture assay system. 3D co-culture of cancer and immune cells is a powerful platform for disease modeling and therapies testing because it can mimic the tumor micro-environment and complex cellular interactions. In this study we evaluated the immunomodulatory effect of chemotherapy on spheroid-T cells interactions in response to PD-L1 inhibition in triple-negative breast cancer. MCF7 and MDA231 cell lines with differential PD-L1 status were formed into spheroids and used as a tumor model. T cells were activated from PBMCs using ImmunoCult CD3/CD28 T cell Activator. Co-culture assays were performed over 72 hr in a Pu·MA System. The Pu·MA System is an automated microfluidic platform that enables phenotypic and functional assays using physiologically relevant 3D cell models. Cancer spheroids and T cells were cultured, manipulated, and measured in a single well of a microfluidic flowchip. The platform integrates 1) 3D cell model with delivery of immune cells, 2) drug delivery, 3) imaging of phenotypic features and 4) functional profiling for cytokine secretion and viability. T cells-spheroid interaction, invasion and cell viability was assessed using high-content fluorescence imaging CellVoyager CQ1 system. IL2, IFN-γ and TNF-α secretion was measured in collected supernatants using Lumit immunoassays. After viability determination, co-cultures were fixed and stained for cancer and T cell markers (E-Cadherin, F-Actin, CD3, CD8) using automated IF staining protocol and then imaged. Image analysis revealed colocalization and infiltration of the T cells into the spheroids. Disintegration of spheroid, loss of circular shape, and increased number of dead cancer cells indicated T cell mediated cancer cell death. To evaluate the immunomodulatory effect of chemotherapy on spheroid-T cells interactions in response to PD-L1 inhibition, co-cultures were exposed to PD-L1 inhibitor Atezolizumab in the presence or absence of Cisplatin/Pemetrexed. We have analyzed a shift in T cell-mediated killing activity and function in the presence or absence of chemotherapeutics. The proposed co-culture platform can be further extended to a more complex patient-derived 3D models using different cell types. Our functional immune-oncology 3D platform allows to study the crosstalk between immune, cancer and other cell interactions, evaluate new drug candidates and assess individual therapeutic approaches to advance precision medicine. Citation Format: Ekaterina Moroz Nikolov, Anthony Thai, Lila Cooper, Mahomi Suzuki, Arvonn Tully, Rashmi Rajendra, Evan F. Cromwell. Evaluation of the chemotherapy potential to improve the anti-cancer efficacy of PD-L1 inhibition using novel 3D microfluidic co-culture platform. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4559.