Identification of Novel Low-Density Neutrophil Markers Through Unbiased High-Dimensional Flow Cytometry Screening in Non-Small Cell Lung Cancer Patients.

Paulina Valadez-Cosmes,A Mcgarry Houghton,Rudolf Schicho,Martin Pichler,Luka Brcic,Kathrin Maitz,Sofia Raftopoulou,Zala Nikita Mihalic,Oliver Kindler,Akos Heinemann,Jörg Lindenmann,Melanie Kienzl,Julia Kargl,Melanie Fediuk,Ana Santiso

doi:10.3389/fimmu.2021.703846

Abstract

Neutrophils have been described as a phenotypically heterogeneous cell type that possess both pro- and anti-tumor properties. Recently, a subset of neutrophils isolated from the peripheral blood mononuclear cell (PBMC) fraction has been described in cancer patients. These low-density neutrophils (LDNs) show a heterogeneous maturation state and have been associated with pro-tumor properties in comparison to mature, high-density neutrophils (HDNs). However, additional studies are necessary to characterize this cell population. Here we show new surface markers that allow us to discriminate between LDNs and HDNs in non-small cell lung cancer (NSCLC) patients and assess their potential as diagnostic/prognostic tool. LDNs were highly enriched in NSCLC patients (median=20.4%, range 0.3-76.1%; n=26) but not in healthy individuals (median=0.3%, range 0.1-3.9%; n=14). Using a high-dimensional human cell surface marker screen, we identified 12 surface markers that were downregulated in LDNs when compared to HDNs, while 41 surface markers were upregulated in the LDN subset. Using flow cytometry, we confirmed overexpression of CD36, CD41, CD61 and CD226 in the LDN fraction. In summary, our data support the notion that LDNs are a unique neutrophil population and provide novel targets to clarify their role in tumor progression and their potential as diagnostic and therapeutic tool.

Highlights

Lung cancer is the leading cause of cancer deaths worldwide and kills more patients each year than does breast, colon, prostate and pancreatic cancer, combined [1]
To determine whether low-density neutrophils (LDNs) were present in this non-small cell lung cancer (NSCLC) patient cohort, blood samples were collected from NSCLC patients, regardless of disease stage
We found that the LDN fraction was significantly increased in NSCLC patients when compared to healthy volunteers

Summary

Introduction

Lung cancer is the leading cause of cancer deaths worldwide and kills more patients each year than does breast, colon, prostate and pancreatic cancer, combined [1]. Most patients are diagnosed at advanced stage with limited treatment options and overall five-year survival rates are below 18% [2]. Detection at early stage, when the disease is still localized, significantly increases five-year survival rates to 55%; only 16% of lung cancer cases are diagnosed at early stage. The two main lung cancer types are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) [2]. NSCLC comprises mainly of lung adenocarcinoma and lung squamous cell carcinoma, representing ~80% of all lung cancer cases [3]. Diagnosis at advanced stage and poor outcome for most patients, highlights the need for novel biomarkers to improve early lung cancer detection and tools to monitor therapy response

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Conclusion