Abstract 5079: Immuno-competent 3d in vitro tumor models as novel platform to assess combinatorial biologics therapy

Abstract

Abstract Background: Immunotherapy has revolutionized cancer treatment, but clinical success is still limited to a subset of patients, underlining the need for novel therapeutic targets. Available ex vivo animal platforms for drug screening show limitations due to only partial recapitulation of tumor-intrinsic features and of the interactions of tumors with stromal/immune cells. Here, we review our 3D InSightTM tumor models, a complex in-vitro platform allowing to study the efficacy of immune-targeting agents on tumor infiltration and killing by peripheral blood mononuclear cells (PBMCs) and to acquire insights on the modulatory capacity of immune checkpoint inhibitors. Aim: In the present study we have developed a 3D tumor - immune cell coculture model and evaluated its application to study the effect of immune checkpoint inhibitors on tumor viability, cytokine secretion, and immune cell infiltration. Material and Methods: Lung carcinoma GFP-A549 cells were cultured with dermal fibroblasts and PBMCs in Akura 96/384-well plates. Immune cells were pre-treated using different activation protocols to induce priming and pT-cell exhaustion. We assessed the effect of PD-1 inhibitors in combination with cytokines for potential synergistic anti-cancer effects. Killing activity and effector function of T cells were evaluated by measuring tumor microtissue size by automatic stage fluorescence microscopy and measuring release of IL-6, TNF, IFNγ and GM-CSF with a MAGPIXTM Luminex system over time. Immune tumor infiltration was quantified using fluorescent staining of CD3+ cells and the effect of the immune cell attack on the tumor cells was assessed by IHC staining. Results: Combination treatment with cytokines and anti-PD-1 led to higher release of IL-6/TNF/IFNγ/GM-CSF and increased tumor microtissue infiltration by CD3+ lymphocytes, stronger expression of Granzyme B, resulting in enhanced tumor killing and apoptosis. Conclusion: Our 3D InSightTM tumor models can be successfully employed for optimal high throughput screening of biologics to unveil the efficacy and anti-tumor efficacy of immune-targeting therapeutic agents. Citation Format: Irina Agarkova, Nicole Buschmann, Silvan Strebel, Armin Wolf, Francesca Chiovaro. Immuno-competent 3d in vitro tumor models as novel platform to assess combinatorial biologics therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5079.