An Immunocompetent Microphysiological System to Simultaneously Investigate Effects of Anti-Tumor Natural Killer Cells on Tumor and Cardiac Microtissues.

Oanh T P Nguyen,Weijia Wang,Timm Schroeder,Jihyun Lee,Christian Lohasz,Andreas Hierlemann,Patrick M Misun

doi:10.3389/fimmu.2021.781337

Abstract

Existing first-line cancer therapies often fail to cope with the heterogeneity and complexity of cancers, so that new therapeutic approaches are urgently needed. Among novel alternative therapies, adoptive cell therapy (ACT) has emerged as a promising cancer treatment in recent years. The limited clinical applications of ACT, despite its advantages over standard-of-care therapies, can be attributed to (i) time-consuming and cost-intensive procedures to screen for potent anti-tumor immune cells and the corresponding targets, (ii) difficulties to translate in-vitro and animal-derived in-vivo efficacies to clinical efficacy in humans, and (iii) the lack of systemic methods for the safety assessment of ACT. Suitable experimental models and testing platforms have the potential to accelerate the development of ACT. Immunocompetent microphysiological systems (iMPS) are microfluidic platforms that enable complex interactions of advanced tissue models with different immune cell types, bridging the gap between in-vitro and in-vivo studies. Here, we present a proof-of-concept iMPS that supports a triple culture of three-dimensional (3D) colorectal tumor microtissues, 3D cardiac microtissues, and human-derived natural killer (NK) cells in the same microfluidic network. Different aspects of tumor-NK cell interactions were characterized using this iMPS including: (i) direct interaction and NK cell-mediated tumor killing, (ii) the development of an inflammatory milieu through enrichment of soluble pro-inflammatory chemokines and cytokines, and (iii) secondary effects on healthy cardiac microtissues. We found a specific NK cell-mediated tumor-killing activity and elevated levels of tumor- and NK cell-derived chemokines and cytokines, indicating crosstalk and development of an inflammatory milieu. While viability and morphological integrity of cardiac microtissues remained mostly unaffected, we were able to detect alterations in their beating behavior, which shows the potential of iMPS for both, efficacy and early safety testing of new candidate ACTs.

Highlights

The lack of treatment options renders cancer one of the major health burdens of our time
In an effort to narrow the gap between in-vitro studies and the in-vivo situation, we developed an Immunocompetent microphysiological systems (iMPS), which allows for coculturing of anti-tumor immune cells and 3D MTs
To accommodate natural killer (NK) cells in suspension and to promote their direct interaction with 3D MTs, we adapted the chip by computer numerical control (CNC) micro-milling: (i) We introduced a drop-shaped cellenrichment zone in the medium reservoirs (Figure 1A, ii and iii, left panels)

Summary

Introduction

The lack of treatment options renders cancer one of the major health burdens of our time. The cells are expanded in vitro and, in some cases, genetically engineered to increase their lifespan and in-vivo tumor-killing activity High numbers of these immune cells are transferred back into the patient to mediate anti-tumor activity [7]. The high anti-tumor activity evidenced in pre-clinical invitro screenings and the contrasting lack of efficacy afterwards in vivo highlight the poor in vitro-to-in vivo translatability of complex treatments. Such poor translatability has been attributed mainly to the widespread use of conventional two-dimensional (2D) cell cultures and animal models for pre-clinical evaluations [11]

Methods

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Discussion

Conclusion