Evaluating natural killer cell cytotoxicity against solid tumors using a microfluidic model

Abstract

2019) Evaluating natural killer cell cytotoxicity against solid tumors using a microfluidic model, OncoImmunology, 8:3, 1553477, ABSTRACT Immunotherapies against solid tumors face additional challenges compared with hematological cancers. In solid tumors, immune cells and antibodies need to extravasate from vasculature, find the tumor, and migrate through a dense mass of cells. These multiple steps pose significant obstacles for solid tumor immunotherapy and their study has remained difficult using classic in vitro models based on Petri dishes. In this work, a microfluidic model has been developed to study natural killer cell response. The model includes a 3D breast cancer spheroid in a 3D extracellular matrix, and two flanking lumens lined with endothelial cells, replicating key structures and components during the immune response. Natural Killer cells and antibodies targeting the tumor cells were either embedded in the matrix or perfused through the lateral blood vessels. Antibodies that were perfused through the lateral lumens extravasated out of the blood vessels and rapidly diffused through the matrix. However, tumor cell-cell junctions hindered antibody penetration within the spheroid. On the other hand, natural killer cells were able to detect the presence of the tumor spheroid several hundreds of microns away and penetrate the spheroid faster than the antibodies. Once inside the spheroid, natural killer cells were able to destroy tumor cells at the spheroid periphery and, importantly, also at the innermost layers. Finally, the combination of antibody-cytokine conjugates and natural killer cells led to an enhanced cytotoxicity located mostly at the spheroid periphery. Overall, these results demonstrate the utility of the model for informing immunotherapy of solid tumors. ARTICLE HISTORY

Human Tumor‐Lymphatic Microfluidic Model Reveals Differential Conditioning of Lymphatic Vessels by Breast Cancer Cells

“…In this work, we developed a tumor‐lymphatic microfluidic device for coculturing tubular lymphatic vessels and breast cancer cells to study their crosstalk. The design of the device was based on previous methods for making endothelial vessels in natural extracellular matrix (ECM) hydrogel and for coculturing these vessels with breast cancer cells . The device comprised a chamber to inject an unpolymerized collagen type I hydrogel and two adjacent PDMS rods suspended in the chamber ( Figure A).…”

“…Collectively, our results demonstrate that different breast cancer subtypes alter lymphatic vessel physiology to different degrees and that our model can be used to better understand the tumor‐lymphatic crosstalk that contributes to lymphatic vessel dysfunction. Previous studies have analyzed the chemokines secreted by breast cancer cells, including MCF7 and MDA‐MB‐231 cells . These studies have identified multiple chemokines that could be driving the lymphangiogenic process observed in the microfluidic device.…”

“…Microfluidic Device Concept and Fabrication : The tumor‐lymphatic microfluidic model was a two‐layer polydimethylsiloxane (PDMS)‐based device fabricated using soft lithography (Figure A). Its design was based on previously developed methods for generating lumens in ECM hydrogel and coculturing these lumens with tumor cells . The basic device concept consisted of two adjacent PDMS rods suspended in a gel chamber, such that they could be encapsulated in ECM gel and removed after gel polymerization to form separate hollow lumens.…”

3D Immunocompetent Organ‐on‐a‐Chip Models

“…Reproduced with permission. [ 163 ] Copyright 2018, Taylor & Francis. C) 3D microfluidic device for MDOTS/PDOTS culture.…”

“…Moreover, a 3D breast cancer model was developed to study NK cell immunotherapies and antibody‐dependent cell cytotoxicity (ADCC), in which breast cancer cell (MCF‐7) spheroids were encapsulated in a collagen hydrogel, individually or in combination with NK‐92 or the CD16‐positive NK‐92, whereas two lateral lumens were seeded with HUVECs (Figure 5B a). [ 163 ] The antiepithelial cell adhesion molecule (EpCAM) antibody was introduced through the endothelialized channel or directly incorporated in the hydrogel to understand the dynamics of antibodies supplied and their effect on NK cytotoxicity. The results indicated that antibodies present in the TME were taken up by the tumor cells, whereas the penetration capacity of the antibodies into the spheroids was hindered by endothelial tight junctions.…”