Deciphering Innate Immune Cell-Tumor Microenvironment Crosstalk at a Single-Cell Level

Abstract

The tumor microenvironment encompasses various innate immune cells which regulate tumor progression. Exploiting innate immune cells is a new frontier of cancer immunotherapy. However, the classical surface markers for cell-type classification cannot always well-conclude the phenotype, which will further hinge our understanding. The innate immune cells include dendritic cells, monocytes/macrophages, natural killer cells, and innate lymphoid cells. They play important roles in tumor growth and survival, in some cases promoting cancer, in other cases negating cancer. The precise characterization of innate immune cells at the single-cell level will boost the potential of cancer immunotherapy. With the development of single-cell RNA sequencing technology, the transcriptome of each cell in the tumor microenvironment can be dissected at a single-cell level, which paves a way for a better understanding of the cell type and its functions. Here, we summarize the subtypes and functions of innate immune cells in the tumor microenvironment based on recent literature on single-cell technology. We provide updates on recent achievements and prospects for how to exploit novel functions of tumor-associated innate immune cells and target them for cancer immunotherapy.

Non‐contact immunological signaling for highly‐efficient regulation of the transcriptional map of human monocytes

“…In fact, transcriptomic analyses of circulating monocytes from different types of cancers show unique and distinct gene profile. 15 The findings herein are demonstrated by monitoring changes in gene and protein expression together with monocytes' volatile signature in co-cultured communication set-ups that have no physical contact, followed by characterizing the VMs emitted at different time points of co-culturing. Unlike cytokines, VMs' low molecular weight and relatively simple chemical structure possibly indicate that cells use VMs as part of their signal network, since the genetic and energetic value of producing them are far lower than for more complex proteins and secondary metabolites.…”

“…Nevertheless, our understanding of the mechanisms governing monocyte reprogramming into protumoral phenotype upon extravasation in the tumor. In fact, transcriptomic analyses of circulating monocytes from different types of cancers show unique and distinct gene profile 15 …”

“…In fact, transcriptomic analyses of circulating monocytes from different types of cancers show unique and distinct gene profile. 15 …”

Combined bulk RNA and single-cell RNA analyses reveal TXNL4A as a new biomarker for hepatocellular carcinoma

“…The scRNA sequencing technology is an effective tool for analyzing immune infiltration (17)(18)(19) Therefore, two scRNA sequencing datasets (GSE140228_10X and GSE166635) were analyzed to investigate TXNL4A expression in each cell cluster using the TISCH2 database (20).…”

A novel classifier combining G protein-coupled receptors and the tumor microenvironment is associated with survival status in glioblastoma

“…The tumor microenvironment (TME) has emerged as a crucial player in cancer progression, particularly involving immune cells ( Takasugi et al, 2022 ; Tamai et al, 2022 ). Tumor-infiltrating lymphocytes (TILs), including T cells, are important cytotoxic fractions within the TME ( Sugimura and Chao, 2022 ). Understanding the function and mechanisms of T cells in the TME can provide valuable insights for glioma treatment, especially immunotherapy ( Boissonnas and Combadière, 2022 ; Li et al, 2022 ).…”