Utilizing Dynamic Single-Cell Analysis to Discover a Clinically Effective Chimeric Antigen Receptor T-Cell Subset for Treating Diffuse Large B-Cell Lymphoma

Research Background

Chimeric antigen receptor (CAR) T-cell therapy has been proven to be an effective treatment for B-cell malignancies. However, it remains challenging to predict individual clinical responses to CAR T-cell therapy. By integrating functional and molecular phenotyping, it is hoped to reveal cellular characteristics associated with the therapeutic efficacy of CAR T-cells, thereby promoting the development and application of this therapy.

Research Institutions and Publishing Journal

This research was a collaborative effort by researchers from the University of Houston, Kite Pharma, Baylor College of Medicine at Texas Children’s Hospital, The University of Texas MD Anderson Cancer Center, and other institutions. The paper was published in the journal Nature-Cancer.

Research Methods and Key Findings

Researchers utilized time-lapse imaging microscopy to measure the dynamic interactions between CAR T-cells and tumor cells, and integrated subcellular molecular phenotyping and single-cell RNA sequencing data to perform a multidimensional single-cell analysis of CAR T-cell products infused in 16 patients with diffuse large B-cell lymphoma. They found:

1) Compared to patients with partial remission or progression, complete remission patients had an enrichment of a CD8+ T-cell subset (termed CD8-fit T-cells) in their CAR T-cell population.

2) CD8-fit T-cells possessed the ability to migrate, continuously kill tumor cells, and had moderate mitochondrial and lysosomal volumes.

3) In single-cell RNA sequencing data, CD8-fit T-cells were enriched for the expression of killing-related genes, cell motility-related genes, and metabolic pathways (such as the PGC1α pathway).

4) The CD8-fit T-cell subset was associated with clinical remission responses, tumor infiltration, and expansion, and was validated in other datasets.

5) Selective enrichment of migratory CAR T-cells could increase the proportion of CD8-fit T-cells and enhance anti-tumor activity in vivo.

6) Inhibition of AMP-activated protein kinase (AMPK) reduced T-cell migration and function, suggesting a key role for AMPK in regulating CD8-fit T-cells.

Research Significance

This study utilized multidimensional single-cell analysis to discover the CD8-fit T-cell subset, an effective CAR T-cell population associated with clinical efficacy, and revealed its molecular characteristics and regulatory mechanisms. This finding can guide the optimization and evaluation of CAR T-cell therapy products, promoting the development and application of this therapy, and bringing more predictable and durable clinical benefits to patients.