Cancer associated fibroblast-T cell crosstalk promotes purinergic synthesis in non-small cell lung cancer (NSCLC).
CAF and T-cell interactions may enhance adenosine production, potentially contributing to immune evasion in NSCLC, but clinical implications require further investigation.
Where it sits
this study against the rest of the ara 290 corpusSummary and findings
This study investigated the role of cancer-associated fibroblast (CAF) and T-cell interactions in the adenosine pathway in non-small cell lung cancer (NSCLC). CD4+ and CD8+ T cells were co-cultured with CAFs, and the expression of CD39 and CD73 was assessed. The study found upregulated expression of these markers, leading to increased AMP and adenosine production.
Abstract
The most abundant stromal cells of the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs), inhibit the cytotoxic T cell response in solid tumors. CD39 and CD73 together deplete extracellular ATP in the TME to produce adenosine, which can promote tumor immune evasion. We aimed to investigate the role of CAF-T-cell crosstalk in the adenosine pathway in NSCLC. CD4<sup>+</sup> and CD8<sup>+</sup> T cells were flow sorted from <i>in vitro</i> culture with or without CAFs, and RNA-Seq was performed using the nCounter platform (NanoString). The expression of cell surface markers involved in adenosine production was assessed using flow cytometry in CAFs and peripheral T cells from healthy donors or early NSCLC patients following <i>in vitro</i> co-culture. Purinergic synthesis of AMP and adenosine was measured by HPLC. TCGA data was used to investigate the translational relevance of adenosine signaling in NSCLC, and NanoString Geomx was performed to investigate differences in the transcriptomics of tumor stromas with a high versus low adenosine signature. CD4<sup>+</sup> and CD8<sup>+</sup> T cells isolated from <i>in vitro</i> co-culture with CAFs show upregulated expression of CD39 and CD73, which results in functionally relevant production of AMP and adenosine. TCGA data illustrates that adenosine signaling is predictive of poor outcome in lung squamous cell carcinoma. Spatial transcriptomics (GeoMx) of the tumor stroma of early untreated NSCLC patients shows a downregulation of immune-related genes in lung squamous-cell carcinoma. CAF T cell crosstalk promotes the expression of CD39 and CD73 on CAFs and T cells, resulting in an increased synthesis of AMP and adenosine <i>in vitro</i>.
Background
The study addresses the interaction between cancer-associated fibroblasts (CAFs) and T cells in the tumor microenvironment of non-small cell lung cancer (NSCLC). Prior research has shown that CAFs can inhibit cytotoxic T cell responses, contributing to tumor immune evasion. This study is significant as it explores the molecular mechanisms behind this interaction, particularly focusing on the adenosine pathway, which is known to play a role in immune suppression.
Methods
The study utilized an in vitro co-culture model of CD4+ and CD8+ T cells with cancer-associated fibroblasts (CAFs). RNA sequencing was performed using the nCounter platform to assess gene expression. Flow cytometry was used to evaluate cell surface markers, and purinergic synthesis was measured by HPLC. Additionally, TCGA data was analyzed for translational relevance, and spatial transcriptomics was conducted using NanoString Geomx.
Results
The primary observation was the upregulation of CD39 and CD73 expression on T cells after co-culture with CAFs, leading to increased production of AMP and adenosine. TCGA data analysis indicated that adenosine signaling correlates with poor outcomes in lung squamous cell carcinoma. Spatial transcriptomics revealed a downregulation of immune-related genes in the tumor stroma of early untreated NSCLC patients.
Interpretation
The findings suggest that CAF-T cell crosstalk enhances adenosine production, which may contribute to immune evasion in NSCLC. While the study provides mechanistic insights, the clinical significance remains uncertain due to the lack of direct patient data. The results align with previous literature on the role of adenosine in tumor progression, but further research is needed to confirm these findings in clinical settings.
Key findings
- CD4+ and CD8+ T cells show upregulated expression of CD39 and CD73 after co-culture with CAFs.
- Increased synthesis of AMP and adenosine was observed in vitro.
- Adenosine signaling is predictive of poor outcomes in lung squamous cell carcinoma according to TCGA data.
- Spatial transcriptomics shows downregulation of immune-related genes in lung squamous-cell carcinoma stroma.
Limitations
- In vitro only, no human clinical data
- Bioinformatics analysis without clinical validation
- Potential confounding from co-culture conditions
- No direct measurement of clinical outcomes