Chronic Obstructive Pulmonary Disease and Cigarette Smoke Lead to Dysregulated Mucosal-associated Invariant T-Cell Activation

Identification of benzo(a)pyrene-related toxicological targets and their role in chronic obstructive pulmonary disease pathogenesis: a comprehensive bioinformatics and machine learning approach

BACKGROUND

Chronic obstructive pulmonary disease (COPD) pathogenesis is influenced by environmental factors, including Benzo(a)pyrene (BaP) exposure. This study aims to identify BaP-related toxicological targets and elucidate their roles in COPD development.

METHODS

A comprehensive bioinformatics approach was employed, including the retrieval of BaP-related targets from the Comparative Toxicogenomics Database (CTD) and Super-PRED database, identification of differentially expressed genes (DEGs) from the GSE76925 dataset, and protein-protein interaction (PPI) network analysis. Functional enrichment and immune infiltration analyses were conducted using GO, KEGG, and ssGSEA algorithms. Feature genes related to BaP exposure were identified using SVM-RFE, Lasso, and RF machine learning methods. A nomogram was constructed and validated for COPD risk prediction. Molecular docking was performed to evaluate the binding affinity of BaP with proteins encoded by the feature genes.

RESULTS

We identified 72 differentially expressed BaP-related toxicological targets in COPD. Functional enrichment analysis highlighted pathways related to oxidative stress and inflammation. Immune infiltration analysis revealed significant increases in B cells, DC, iDC, macrophages, T cells, T helper cells, Tcm, and TFH in COPD patients compared to controls. Correlation analysis showed strong links between oxidative stress, inflammation pathway scores, and the infiltration of immune cells, including aDC, macrophages, T cells, Th1 cells, and Th2 cells. Seven feature genes (ACE, APOE, CDK1, CTNNB1, GATA6, IRF1, SLC1A3) were identified across machine learning methods. A nomogram based on these genes showed high diagnostic accuracy and clinical utility. Molecular docking revealed the highest binding affinity of BaP with CDK1, suggestive of its pivotal role in BaP-induced COPD pathogenesis.

CONCLUSIONS

The study elucidates the molecular mechanisms of BaP-induced COPD, specifically highlighting the role of oxidative stress and inflammation pathways in promoting immune cell infiltration. The identified feature genes may serve as potential biomarkers and therapeutic targets. Additionally, the constructed nomogram demonstrates high accuracy in predicting COPD risk, providing a valuable tool for clinical application in BaP-exposed individuals.

Cigarette smoke components modulate the MR1-MAIT axis

Tobacco smoking is prevalent across the world and causes numerous diseases. Cigarette smoke (CS) compromises immunity, yet little is known of the components of CS that impact T cell function. MR1 is a ubiquitous molecule that presents bacterial metabolites to MAIT cells, which are highly abundant in the lungs. Using in silico, cellular, and biochemical approaches, we identified components of CS that bind MR1 and impact MR1 cell surface expression. Compounds, including nicotinaldehyde, phenylpropanoid, and benzaldehyde-related scaffolds, bound within the A' pocket of MR1. CS inhibited MAIT cell activation, ex vivo, via TCR-dependent and TCR-independent mechanisms. Chronic CS exposure altered MAIT cell phenotype and function and attenuated MAIT cell responses to influenza A virus infection in vivo. MR1-deficient mice were partially protected from the development of chronic obstructive pulmonary disease (COPD) features that were associated with CS exposure. Thus, CS can impair MAIT cell function by diverse mechanisms, and potentially contribute to infection susceptibility and disease exacerbations.

COPD and Immune Checkpoint Inhibitors for Cancer: A Literature Review

Purpose

Immune checkpoint inhibitors are a standard treatment option for many patients with cancer and are most frequently used to treat lung cancer. Chronic obstructive pulmonary disease (COPD) is the most common comorbidity of patients with lung cancer. As the cancer-specific survival of patients with lung cancer continues to increase with modern treatments, it is critical to optimize comorbidities to improve overall survival. This literature review aimed to summarize current research on the impact of COPD upon immunotherapy outcomes.

Methods

A comprehensive search was conducted in the PubMed database using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria focused on peer-reviewed articles published between 2010 and 2024 that addressed COPD, cancer, and immune checkpoint inhibitors. The study team screened the studies for relevance and then synthesized them narratively.

Results

This review identified 37 studies that met the inclusion criteria. Findings suggest that COPD is predictive of improved efficacy but slightly worse toxicity from immune checkpoint inhibitor therapy. The chronic inflammation of COPD leads to immune exhaustion including the overexpression of immune checkpoints on T-cells. Particularly within "hot" tumors that have higher concentrations of tumor-infiltrating lymphocytes, the COPD-related increase in programmed cell death protein 1 (PD-1) signaling likely creates sensitivity to immune checkpoint inhibitors. However, COPD can also lead to respiratory dysfunction, debility, and interstitial lung disease; each of which increases the severity of immune-related adverse events.

Conclusion

COPD is a critical comorbidity that has a significant impact on many patients with cancer who receive treatment with immune checkpoint inhibitors. Future research is needed to design interventions to optimize COPD care in this high-risk patient population.

RNAseq of INOCA patients identifies innate, invariant, and acquired immune changes: potential autoimmune microvascular dysfunction

Background

Ischemia with non-obstructive coronary arteries (INOCA) is a major clinical entity that involves potentially 20%-30% of patients with chest pain. INOCA is typically attributed either to coronary microvascular disease and/or vasospasm, but is likely distinct from classical coronary artery disease (CAD).

Objectives

To gain insights into the etiology of INOCA and CAD, RNA sequencing of whole blood from patients undergoing both stress testing and elective invasive coronary angiography (ICA) was conducted.

Methods

Stress testing and ICA of 177 patients identified 40 patients (23%) with INOCA compared to 39 controls (stress-, ICA-). ICA+ patients divided into 38 stress- and 60 stress+. RNAseq was performed by Illumina with ribosomal RNA depletion. Transcriptome changes were analyzed by DeSeq2 and curated by manual and automated methods.

Results

Differentially expressed genes for INOCA were associated with elevated levels of transcripts related to mucosal-associated invariant T (MAIT) cells, plasmacytoid dendritic cells (pcDC), and memory B cells, and were associated with autoimmune diseases such as rheumatoid arthritis. Decreased transcripts were associated with neutrophils, but neutrophil transcripts, per se, were not less abundant in INOCA. CAD transcripts were more related to T cell functions.

Conclusions

Elevated transcripts related to pcDC, MAIT, and memory B cells suggest an autoimmune component to INOCA. Reduced neutrophil transcripts are likely attributed to chronic activation leading to increased translation and degradation. Thus, INOCA could result from stimulation of B cell, pcDC, invariant T cell, and neutrophil activation that compromises cardiac microvascular function.

MAIT cells are associated with responsiveness to neoadjuvant immunotherapy in COPD-associated NSCLC

BACKGROUND

Patients with non-small cell lung cancer (NSCLC) and chronic obstructive pulmonary disease (COPD) experience worse clinical outcomes but respond better to immunotherapy than patients with NSCLC without COPD. Mucosal-associated invariant T (MAIT) cells, a versatile population of innate immune T lymphocytes, have a crucial function in the response to infection and tumors. This study investigated the distribution of MAIT cells in COPD-associated NSCLC and their involvement in the immune response.

METHODS

Flow cytometry, immunohistochemistry, and immunofluorescence were performed on tissue samples of patients with NSCLC, with or without COPD, treated with or without anti-programmed death 1 (PD1) immunotherapy. MAIT cells were stimulated with 5-OP-RU using a mouse subcutaneous tumor model.

RESULTS

Tumors contained significantly more MAIT cells than paraneoplastic tissues, and CD8+ MAIT cells accounted for more than 90% of these cells. Patients with NSCLC and COPD had higher CD8+ MAIT cell counts than those with NSCLC without COPD. Additionally, patients with NSCLC and COPD displayed reduced expression of the activation marker, CD69, and functional markers, granzyme B (GZMB) and interferon γ (IFNγ), and higher expression of the immune exhaustion marker, PD1. Among patients who received immunotherapy, the proportion with a complete or partial response was higher in those with COPD than in those without COPD. In patients with NSCLC and COPD, the major pathologic response (MPR) group had higher MAIT levels than those in the no major pathologic response (NPR) group. In the mouse subcutaneous tumor model stimulation of MAIT cells using 5-OP-RU enhanced the antitumor effects of anti-PD1.

CONCLUSIONS

In patients with NSCLC and COPD, response to immunotherapy is associated with accumulation of CD8+ MAIT cells showing immune exhaustion. These findings may contribute to innovative approaches for immunotherapy targeting CD8+ MAIT cells.

Evaluating the effect of immune checkpoint inhibitors on venous thromboembolism in non-small cell lung cancer patients

OBJECTIVE

Currently, immune checkpoint inhibitors (ICIs) therapy is one of the main methods of treatment in non-small cell lung cancer (NSCLC). This study aimed to explore the risk factors of VTE and evaluate the effect of ICIs on VTE in patients with NSCLC.

RESEARCH DESIGN AND METHODS

We retrospectively studied patients with NSCLC who were divided into VTE group and without VTE (Non-VTE) group. We identified the risk factors of VTE in NSCLC patients and evaluated the effect of ICIs on VTE in NSCLC patients.

RESULTS

We found that clinical stage III-IV (P = 0.015) and Khorana score (KS) ≥ 2 (P = 0.047) were independent risk factors for the occurrence of VTE in NSCLC, and treatment with ICIs reduced the risk of VTE occurrence (P = 0.028). There were no differences of survival rates in the 12-month (P = 0.449), 24-month (P = 0.412), or 36-month (P = 0.315) between the VTE and non-VTE groups. History of anti-angiogenic therapy (P = 0.033) and chronic obstructive pulmonary disease (COPD) (P = 0.046) were independent risk factors for VTE in NSCLC patients who were treated with ICIs.

CONCLUSION

This study suggests that we should strengthen anticoagulant therapy when using ICIs for NSCLC patients with a history of anti-angiogenic therapy and COPD.

The impact of puff frequency on respirable particulate matter in mainstream cigarette smoke

BACKGROUND

Inhalation of particulate matter (PM) from cigarette smoke is hazardous to smokers and non-smokers. This contribution simulates the deposition of cigarette PM on the lung surface by trapping tobacco smoke particulates on Croton megalocarpus biochar. This study investigated one commercial cigarette (MM) and one local cigarette (RR).

METHODOLOGY

Biochar was incorporated into the filters of MM and RR cigarettes in order to adsorb PM from mainstream cigarette smoke. A weighed 5 mg of biochar with adsorbed cigarette PM was analyzed using a scanning electron microscope and a Fourier transform infrared spectrometer. The size distribution of cigarette smoke particulates was processed using ImageJ software.

RESULTS

At 15 s puff time, the mean particulate diameters for the commercial and the local cigarettes, respectively, can be classified as coarse ≈ PM10 . Conversely, the mean particulate diameter at 2 s puff time for the commercial cigarette falls under the ultrafine classification of ≤PM2.5 , whereas at the same puff time, the mean particulate diameter for the local cigarette was approximately PM2.5 . Data from Fourier transform infrared spectroscopy indicate the PM in the two model cigarettes contains aromatic structures that feature the C=C bond characterized by an intense absorption band at δs (1600 cm-1 ).

CONCLUSIONS

This study found that PM in mainstream cigarette smoke depends on puff time. Although cigarette smoking was conducted for two model cigarettes, this study can be extended to any other form of cigarette. Moreover, this study emphasizes the need for comprehensive studies on real-world cigarette smoking conditions, taking into account cigarette smokers who use larger puff volumes.