Modeling CAR T Cell Trafficking and Efficacy in Solid Tumors Using a Tumor–Vasculature-on-Chip

Why This Is Important

Solid cancers remain one of the leading causes of death worldwide, many of these diseases are deemed incurable or lack effective therapeutic options. Chimeric Antigen Receptor (CAR) T-cell therapy is a breakthrough in cancer treatment.

Challenges

Despite its success in treating blood cancers, CAR T-cell therapy for solid tumors encounters significant obstacles – including immunosuppressive microenvironments, limited T-cell infiltration, and resistance mechanisms that limit efficacy (1,2).

Need

A physiologically relevant model that enables accurate tracking, evaluation, and optimization of CAR T-cell therapies in solid tumors – from trafficking and infiltration to cytotoxicity.

MIMETAS’ Answer

Organ Model

A 3D tumor-on-a-chip model that combines patient-derived tumor cells with perfused vasculature, ECM, and customizable immune and stromal compartments.

Features

• Perfused 3D Blood Vessels
• Live imaging of T-cell migration & killing
• Barrier-free T-cell movement
• Tunable ECM and cell composition
• Cytokine profiling & immunofluorescence readouts

Offering

Custom CRO Services

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A Tumor-on-a-Chip Model

Solid tumors remain a major challenge for CAR T cell therapy due to limited infiltration, heterogeneous antigen expression, and therapy-induced toxicity. To study how CAR T cells reach and engage solid tumors, MIMETAS scientists developed an on-chip model to evaluate CAR T cell migration and killing capacity. ECM-embedded colorectal cancer (CRC) cells were incorporated into a model comprising endothelium and T cells. CAR T cells were perfused through the human endothelial vessel adjacent to ECM-embedded tumor cells (Figure 1).

Figure 1. Schematic representation of the co-culture set-up. CAR T cells (red) are perfused through the endothelial vessel (light blue) via addition to the perfusion inlet (A1). Upon addition, CAR T cells adhere to the endothelial vessel wall and infiltrate the tumor compartment after undergoing the process of transendothelial migration.

CAR T Cell Trafficking to Tumor Compartment

CAR T cells were perfused through a human endothelial vessel adjacent to ECM-embedded tumor cells, enabling assessment of vascular adhesion, transendothelial migration, and tumor infiltration. CAR T cell infiltration increased over time and was strongly enhanced by a CXCL12 chemokine gradient, indicating active and directed migration (Figure 2A). CAR T cells infiltrated both target and non-target tumor cell compartments. Quantitative analysis revealed distinct infiltration dynamics between these conditions, with differences in the fraction of CAR T cells entering the tumor compartment over time (Figure 2B). These results demonstrate that CAR T cell trafficking is influenced by tumor context and is not solely determined by target recognition.

Figure 2. (A) Migration of fluorescently labelled CAR T cells towards target and non-target tumor compartments in the presence of a CXCL12 gradient over 72 hours of co-culture. (B) Percentage of migrated CAR T cells during 72 hours of co-culture with either target (HT-29) or non-target (A375) tumor cells.

Solid Tumor Killing by CAR T Cells

The colon organoid tubules recapitulate multiple essential epithelial functions. Upon exposure to vitamin D₃, gut cells show strong upregulation of CYP3A4, resulting in increased metabolic activity (Figure 3A). In addition, correct cellular polarisation and reporter expression enable highly reliable and physiologically relevant compound transport across the gut barrier (Figure 3B).

Figure 3. (A) Images of target and non-target tumor cells co-cultured with untransduced T cells or CAR T cells for 72 hours. (B) Cytokine levels after 72 hours of co-culture of target tumor cells with either untransduced T cells or CAR T cells for 72 hours.

Predictive GI Safety Assessment

To evaluate compound-induced GI toxicity, the gut tubules were exposed to increasing compound concentrations for 5 days, followed by assessment of cell viability and barrier integrity (Figure 4A, B). This analysis was performed using a panel of 8 clinically GI-toxic drugs and 10 non-GI-toxic compounds. Using a margin of safety of 60 x Cmax, the model achieved a sensitivity of 75% and a specificity of 100%, demonstrating that the OrganoReady Colon is a powerful screening tool for GI safety assessment in drug development.

Figure 4. (A) Representative time-course images illustrating increasing tumor cell killing with higher CAR T cell doses. Draq7 signal indicates dead cells. (B) Quantitative analysis of tumor area over time demonstrates a clear dose–response relationship between CAR T cell dosing and tumor clearance.

Summary

Simulation of Solid Tumor Microenvironment: Inclusion of factors such as immunosuppressive cells, soluble factors, and ECM stiffness.
Accurate Immune Modeling: Real-time T-cell migration, engagement and cytokine release.
Effective Construct Testing: Compare efficacy, and targeting precision of CAR T variants

References

Chen Y, E C-Y, Gong Z-W, Liu S, Wang Z-X, Yang Y-S, et al. Chimeric antigen receptorengineered T-cell therapy for liver cancer. Hepatobiliary & Pancreatic Diseases International. 2018 Aug;17(4):301–9. doi:10.1016/j.hbpd.2018.05.005
Siddiqui RS, Sardar M. A systematic review of the role of chimeric antigen receptor T (CAR-T) cell therapy in the treatment of solid tumors. Cureus. 2021 Apr 15; doi:10.7759/cureus.14494