Adoptive cell therapy (ACT) has transformed treatment for blood cancers like leukemia and lymphoma, with CAR-T therapies achieving remarkable remission rates. However, the story for solid tumors remains frustratingly different. Despite showing potent anti-tumor activity in the lab, most cell therapies fail when treating solid tumors. The reason? These therapeutic cells never reach their target.
The numbers tell a sobering story: only a small fraction of infused T cells successfully infiltrate solid tumors, and this poor trafficking is a primary reason that cell therapies for solid tumors achieve response rates far below those seen in hematologic malignancies. Current methods to characterize therapeutic T cells rely heavily on phenotypic markers and static assays that fail to predict which cells will successfully navigate the complex journey from the bloodstream into the tumor microenvironment.
To that end, researchers need reliable methods to identify and enrich T cell populations with superior tumor homing capabilities. This requires a functional assessment that goes beyond simply measuring what receptors cells express to understanding how cells actually behave under physiological conditions.
Modeling Tumor Homing with the Adhesion Chromatography™ Platform
In a recent study published in Cell Reports, researchers from Georgia Tech and Emory University utilized Infiltrate Bio's foundational technology, a tumor vasculature-mimicking microfluidic device that predicts CD8+ T cell tumor homing based on functional adhesion behavior. The adhesion chromatography platform replicates the hemodynamic microenvironment of tumor blood vessels, measuring how T cells interact with P-selectin (a critical adhesion molecule expressed by tumor endothelium) under physiological flow conditions.
Using this platform, the research team evaluated both mouse and human CD8+ T cells, separating populations into "free flow" cells that passed through the channel without adhering and "adherent" cells that exhibited robust P-selectin binding under shear flow. The key innovation lies in assessing adhesive function rather than just phenotype, capturing how cells will perform in the dynamic environment of the circulatory system.
Key findings from this research include:
- In vitro adhesion predicts in vivo homing: CD8+ T cells enriched for P-selectin adhesion in the microfluidic device showed significantly enhanced tumor infiltration when adoptively transferred into melanoma-bearing mice (3-4x improvement compared to unsorted populations).
- Superior tumor microenvironment remodeling: The adhesion-enriched T cells not only trafficked to tumors at higher rates but also remodeled the tumor microenvironment more effectively, increasing the presence of therapeutically relevant immune cell populations.
- Synergy with checkpoint blockade: When combined with anti-PD-1 therapy, adoptive transfer of adhesion-enriched T cells significantly improved tumor control compared to either therapy alone or ACT with unenriched cells. This demonstrates that cell quality directly impacts therapeutic synergy.
- Translational relevance for human cells: The platform successfully enriched human CD8+ T cells expanded using clinically relevant protocols, with adhesion-selected populations showing increased P-selectin ligand expression across multiple expansion timepoints.
- Functional characterization beyond phenotype: While adhesion-enriched cells showed distinct P-selectin ligand and CCR7 expression patterns, tumor homing capability correlated with adhesive quality rather than specific T cell subtypes. This reveals that functional assessment provides information that phenotypic analysis alone cannot.
Advancing Cell Therapy Development Through Predictive Adhesion Analysis
Achieved through precise control of shear stress and adhesion molecule presentation in a microfluidic environment, this research demonstrates that functional adhesion testing under physiological conditions can identify therapeutic T cell populations with enhanced tumor infiltration capabilities. The platform addresses a critical gap in cell therapy development: the inability to predict which manufactured cell products will successfully traffic to solid tumors before they're tested in patients.
Learn more about how Infiltrate Bio's Adhesion Chromatography platform can transform your cell therapy development program: