94: Single-cell profiling of tumor-infiltrating T-cell clones in longitudinal peripheral blood samples for clinical studies

Friday, March 24, 2023

10:51 AM – 11:01 AM

Location: Ballroom A

Abstract Presenter(s)

Eihab N. Abdelfatah, MD

Assistant Professor
NYU Long Island School of Medicine
Mineola, New York, United States

Disclosure(s): No financial relationships to disclose

First Author(s)

Eihab N. Abdelfatah, MD

Assistant Professor
NYU Long Island School of Medicine
Mineola, New York, United States

Disclosure(s): No financial relationships to disclose

Author(s)

ML

Mark Long, PhD

Assistant Professor
Roswell Park Comprehensive Cancer Center - Department of Biostatistics and Bioinformatics, United States

Disclosure information not submitted.
RK

Ryutaro Kajihara, PhD

Assistant Professor
Kumamoto University - Department of Biomedical Labarotory Sciences, United States

Disclosure information not submitted.
Takaaki Oba

Postdoctoral fellow
Roswell Park Cancer Institute
Buffalo, New York, United States

Disclosure information not submitted.
TY

Takayoshi Yamauchi, PhD

Assistant Professor
University of Southern California - Department of Surgery, United States

Disclosure information not submitted.
HC

Hongbin Chen, MD, PhD

Associate Professor of Oncology
Roswell Park Comprehensive Cancer Center, United States

Disclosure information not submitted.
JM

Junko Matsuzaki, PhD

Professor
University of Chicago Medicine Comprehensive Cancer Center, United States

Disclosure information not submitted.
BS

Brahm Segal, MD

Professor of Medicine
Roswell Park Comprehensive Cancer Center, United States

Disclosure information not submitted.
GD

Grace Dy, MD

Professor of Oncology
Roswell Park Comprehensive Cancer Center, United States

Disclosure information not submitted.
FI

Fumito Ito, MD, FACS, FSSO

Professor of Surgery
Los Angeles County + University of Southern California (LAC+USC) Medical Center, Los Angeles, CA, USA. Department of Surgery and Norris Comprehensive Cancer Center, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA., United States

Disclosure information not submitted.
KA

Kristopher Attwood, PhD

Biostatistician
Roswell Park Comprehensive Cancer Center, United States

Disclosure information not submitted.

Disclosure(s):

Eihab N. Abdelfatah, MD: No financial relationships to disclose

Introduction: Advances in multi-omics approaches provide an unprecedented opportunity to study multiple molecular modalities at the level of single-cell (sc) or single cellular clones in response to therapy. Here, we elucidate the functional heterogeneity and plasticity of tumor-infiltrating T-cell clones in peripheral blood (PB) during the course of immunotherapy in non-small cell lung cancer (NSCLC) by combining T-cell receptor (TCR) sequencing of tumor tissue with scRNA/TCR sequencing of serial PB samples.

Methods: We collected longitudinal PB samples from NSCLC patients treated with immune checkpoint inhibitor (ICI) therapy at Roswell Park Cancer Center. We flow-sorted CD3⁺T cells from cryopreserved PB mononuclear cells for scRNA/TCR sequencing. We also extracted DNA from the archival pre-treatment tumor, and performed TCR sequencing to identify TCR clonotypes observed in the tumor.

Results: Unsupervised analysis of scRNA/TCR sequencing identified 13 distinct lymphocyte clusters. Of these, 2 clusters of CD8⁺ T cells expressed effector and differentiation associated genes including GZMB, TBX21 and CX3CR1, all of which substantially increased after initiation of ICI therapy. TCR overlap score in PB T cells markedly decreased after single treatment, indicating the evolution of TCR clonotype. Circulating clonally expanded tumor-infiltrating T-cell clones exhibited terminally differentiated effector T cells overexpressing CX3CR1. Consistent with this, flow cytometric analysis of longitudinal PB samples demonstrated an early on-treatment increase of circulating CX3CR1⁺ CD8⁺ T cells. We evaluated 29 patients with advanced NSCLC treated with combined chemotherapy and anti-PD-1/PD-L1 therapy. We found that at least 10% increase of the CX3CR1⁺ subset in circulating CD8⁺ T cells from baseline was associated with response to chemo-immunotherapy, and better overall (p = 0.0265) and progression-free survival (p = 0.0108) on Kaplan-Meier analysis.

Conclusions: Multi-omics approaches could allow single-cell profiling of tumor-infiltrating T-cell clones in longitudinal clinical PB samples, provide insights into the transcriptional landscape and evolution of circulating T cells during treatment, and facilitate the discovery of predictive biomarkers in response to therapy.

Learning Objectives:

Explain the role of multi-omics in evaluating on-treatment biomarkers.
Identify markers, particularly CX3CR1, which indicate the presence of effector and terminally differentiated T cells after treatment with immune checkpoint inhibitors in NSCLC.
Identify that presence of increased circulating CX3CR1+ CD8+ T cells in the peripheral blood of patients with NSCLC treated with immune therapy is associated with positive response and improved survival.