A Multiscale Immuno-Oncology on-Chip System (MIOCS) establishes that collective T cell behaviors govern tumor regression

Abstract

T cell-based tumor immunotherapies such as CAR T cells or immune checkpoint inhibitors harness the cytotoxic potential of T cells to promote tumor regression. However, patient response to immunotherapy remains heterogeneous, highlighting the need to better understand the rules governing a successful T cell attack. Here, we develop a microfluidic-based method to track the outcome of T cell activity on many individual cancer spheroids simultaneously, with a high spatiotemporal resolution. By combining these parallel measurements of T cell behaviors and tumor fate with probabilistic modeling, we establish that the first recruited T cells initiate a positive feedback loop leading to an accelerated effector accumulation on the spheroid. We also provide evidence that cooperation between T cells on the spheroid during the killing phase facilitates tumor destruction. We propose that tumor destruction does not simply reflect the sum of individual T cell activities but relies instead on collective behaviors promoting both T cell accumulation and function. The possibility to track many replicates of immune-tumor interactions with such a level of detail should help delineate the mechanisms and efficacy of various immunotherapeutic strategies.

Cell Culture in Microfluidic Droplets

“…Note that the first-passage time formalism can be applied to any object that executes a random walk before reaching a localized target including cells moving randomly within a hydrogel. Ronteix et al encapsulated immune cells in microfluidic droplets in the presence of a spheroid of cancer cells . Immune cells executed a random exploration in the droplet, which could be characterized by an effective diffusion coefficient.…”

“…(e) Individual T cells tracked in microfluidic droplets and their instantaneous velocity measured at every point of their trajectory in the focal plane. Reprinted from ref . Copyright 2021 Ronteix et al…”

“…(b) Interaction between tumor spheroids and GFP+ T cells can be followed inside the droplets and the tumor cell death measured using specific markers (here caspase 3/7). Reprinted from ref . Copyright 2021 Ronteix et al Scale bar is 50 μm.…”

Engineered Microphysiological Systems for Testing Effectiveness of Cell-Based Cancer Immunotherapies

“…These models typically place tumor spheroids in microwells to image the infiltration and cytotoxicity of lymphocytes [ 41 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 ]. Other studies encapsulate tumor spheroids in hydrogels such as collagen or Matrigel, either embedding the lymphocytes or applying them to the surface of the hydrogel [ 29 , 48 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ]. The advantage of performing these studies in 3D is that lymphocytes must actively migrate through the ECM toward and into the tumor spheroids in order to exert cytotoxic effects, rather than the passive interactions that occur in traditional cytotoxicity assays in which lymphocytes settle onto a 2D cancer cell monolayer.…”

Assessment of CAR-T Cell-Mediated Cytotoxicity in 3D Microfluidic Cancer Co-Culture Models for Combination Therapy

“…With respect to off-chip CAR-T screening approaches, microfluidic technology can be effective in increasing the complexity of the 3D tumour models and the data throughput of the assays when performing combination therapy studies whilst using small sample volumes. Miniaturized 3D immunoassays have been developed using microfluidic and lab-on-a-chip technology, [20][21][22][23][24][25][26][27][28][29] yet their application is still limited in relation to CAR-T studies. [30] For example, Ando et al established a microfluidic assay to study the effect of hypoxic conditions on CAR-T cell behaviour.…”