Role of CD4+ T and CD8+ T Lymphocytes-Mediated Cellular Immunity in Pathogenesis of Chronic Obstructive Pulmonary Disease

The Mediation of Circulating Inflammatory Proteins in the Causal Pathway from Immune Cells to COPD

Objective

Observational studies have indicated that immune cells and circulating inflammatory proteins may play a dual role in the progression of COPD; however, the precise mechanisms remain uncertain. The objective of this study was to ascertain the causal relationship between immune cells and COPD and to quantify the potential role of circulating inflammatory proteins as mediators.

Methods

A two-sample Mendelian randomisation analysis was conducted involving 731 immune cells, 91 inflammatory proteins and COPD, utilising summary-level data from genome-wide association studies. The causal relationships between immune cells, inflammatory proteins and COPD were sequentially analysed by multivariate Mendelian randomisation and validated using Bayesian weighted Mendelian randomisation. Subsequently, sensitivity analyses were conducted, employing Cochran's Q test to assess heterogeneity, MR-PRESSO and MR-Egger tests to assess pleiotropy, and reverse MR and Steiger directionality tests to rule out reverse causality. Lastly, a two-step approach was employed to ascertain the proportion of inflammatory proteins that mediate immune cell-mediated effects in COPD.

Results

The combination of the inverse variance weighting method and the Bayesian weighting algorithm identified 30 immune cells that were found to be causally associated with COPD, as well as eight inflammatory proteins that were associated with COPD. By two-step analysis, six inflammatory proteins were found to mediate the effects of eight immune cell phenotypes on COPD, with CXCL10 having the highest percentage of mediation at 14.49%, followed by IL20RA at 11.47%.

Conclusion

This study provides a comprehensive investigation of the causal relationship between immune cells and COPD, as well as an estimation of the proportion of the effect of inflammatory proteins as mediators. These findings facilitate the identification of individuals at high risk of COPD and offer novel insights for early prevention and clinical intervention.

Correlation Between Vitamin D, Inflammatory Markers, and T Lymphocytes With the Severity of Chronic Obstructive Pulmonary Disease and its Effect on the Risk of Acute Exacerbation: A Single Cross-sectional Study

PURPOSE

Chronic obstructive pulmonary disease (COPD) will become the fourth largest cause of death of chronic diseases in the world in 2030. The incidence of COPD ranked top among chronic diseases in the world. At present, there is a lack of simple and effective drugs for the treatment of COPD and for slowing the progression of the disease. The application of vitamin D as a drug in clinical treatment has been a research hotspot. In this study, we investigated the correlation between serum 25-hydroxyvitamin D (25(OH)D), inflammatory markers, and T lymphocytes with the severity of COPD and its effect on the risk of acute exacerbation.

METHODS

In this study, we recruited hospital inpatients and outpatient clinic patients with COPD. Their levels of 25(OH)D, inflammatory markers, and T lymphocytes were assessed. We built a nomogram model to evaluate the risk of acute exacerbation of COPD.

FINDINGS

The inflammatory mediators were higher in patients with acute exacerbation of COPD (AECOPD) than those in patients with COPD, but 25(OH)D showed the opposite phenomenon. In logistic regression analysis, high levels of neutrophil-lymphocyte ratio, C-reactive protein, and partial pressure of carbon dioxide and low levels of vitamin D, partial pressure of oxygen, and forced expiratory volume in the first as a percentage of predicted were regarded as independent risk factors for AECOPD. These variables were used for the construction of the nomogram model. The AUCs of the model were 0.971 (95% CI, 0.952-0.989), and 0.981 (95% CI, 0.959-1.000) in the training and testing set respectively, demonstrating that the model exhibited high accuracy for the prediction of the risk of acute exacerbation of COPD. The calibration curve of the nomogram found a high degree of consistency between the expected and actual values. The decision curve analysis and clinical impact curve indicated that the nomogram has clinical applicable for patients with COPD.

IMPLICATIONS

A considerable percentage of patients with COPD were found to have insufficient vitamin D levels. Patients with AECOPD reported more symptoms than those with COPD. The variables neutrophil-lymphocyte ratio, C-reactive protein, partial pressure of carbon dioxide, 25(OH)D, partial pressure of oxygen, and forced expiratory volume in the first as a percentage of predicted can be used for the prediction of AECOPD. Accordingly, this study provided experimental rationales for the role of 25(OH)D in the prevention and the potential anti-inflammatory mechanisms involved in the control of the COPD process.

Analysis of Predictive Value of Cellular Inflammatory Factors and T Cell Subsets for Disease Recurrence and Prognosis in Patients with Acute Exacerbations of COPD

Objective

To explore the predictive value of cellular inflammatory factors and T cell subsets for disease recurrence and prognosis in patients with acute exacerbations of chronic obstructive pulmonary disease (COPD).

Methods

Serum samples were collected from the two groups to detect and compare the levels of inflammatory cytokines [interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)], T cell subsets (CD4+, CD8+), and clinical related indicators. Pearson correlation analysis was used to analyze the correlation between inflammatory cytokines, T cell subsets, and clinical indicators. Receiver operating characteristic (ROC) curves were plotted to analyze the predictive value of serum inflammatory factors and T cell subsets for acute exacerbations of COPD.

Results

The observation group had higher levels of IL-1β, IL-6, TNF-α, and CD8+, and lower CD4+ levels (P<0.05). The ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) was lower, while procalcitonin (PCT) and white blood cell count (WBC) were higher (P<0.05). Correlation analysis showed positive correlations between IL-1β, IL-6, TNF-α, and CD8+, and negative correlations with CD4+ and FEV1/FVC (P<0.05). After 6 months, 15 out of 73 patients had acute recurrences, with higher IL-1β, IL-6, TNF-α, and CD8+ levels (P<0.05). Binary logistic regression identified IL-1β, IL-6, TNF-α, and CD8+ as significant predictors of exacerbations, while CD4+ was protective. ROC analysis showed that combined biomarkers had the highest predictive efficiency (AUC = 0.907).

Conclusion

This study is the first to integrate multiple serum inflammatory factors and T cell subsets into a comprehensive predictive model for acute recurrence of COPD within six months (AUC = 0.907), offering a more accurate prediction than traditional methods. The findings underscore the value of these biomarkers in clinical follow-up and highlight their independent predictive power, providing new insights into the interaction between immune markers and clinical indicators in COPD exacerbations.

Inflammation mechanism and research progress of COPD

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease characterized by irreversible progressive airflow limitation, often manifested by persistent cough, sputum production and other respiratory symptoms that pose a serious threat to human health and affect the quality of life of patients. The disease is associated with chronic inflammation, which is associated with the onset and progression of COPD, but anti-inflammatory therapy is not first-line treatment. Inflammation has multiple manifestations and phenotypes, and this heterogeneity reveals different patterns of inflammation, making treatment difficult. This paper aims to explore the direction of more effective anti-inflammatory treatment by analyzing the nature of inflammation and the molecular mechanism of disease occurrence and development in COPD patients, and to provide new ideas for the treatment of COPD patients.

Causal Involvement of Immune Cells in Chronic Obstructive Pulmonary Disease: A Mendelian Randomization Study

Background

The immune cells play a substantial role in the development and progression of chronic obstructive pulmonary disease (COPD). We aim to investigate the causal involvement of immune cells in COPD via a Mendelian randomization (MR) analysis.

Methods

Published genome-wide association studies (GWAS) statistics on immune cells were analyzed, with genetic variants identified as instrumental variables (IVs). Inverse-variance weighting (IVW), weighted median, and MR-Egger regression methods were employed, along with simple mode and weighted mode adopted in the two-sample MR analysis. Sensitivity analysis was conducted to examine the heterogeneity, horizontal pleiotropy, and stability of the causal relationship.

Results

IVW results suggested that CCR2 on CD62L+ plasmacytoid dendritic cells (DC), CCR2 on plasmacytoid DC, CD11b on CD66b++ myeloid cells, CD19 on CD20- CD38- CD24+ memory B cell subset, CD25 on transitional B cells, and CD25++CD8br %CD8br T cells were risk factors for the development of COPD. Besides, CD127 on effector memory-like cytotoxic T lymphocytes lacking expression of co-stimulatory molecule 28 (CD28-EM CTLs) and HLA DR+ NK ACs expressing human leukocyte antigen DR molecules while being natural killer cells (%NK ACs) were protective factors for COPD.

Conclusion

This study unveiled a causal relationship between immune cell phenotype and COPD. These findings offer new insights for the prevention and treatment of COPD using COPD-associated immune cells.

Inhibiting SIRT-2 by AK-7 restrains airway inflammation and oxidative damage promoting lung resurgence through NF-kB and MAP kinase signaling pathway

Introduction

Chronic obstructive pulmonary disease (COPD) is a major global cause of mortality with limited effective treatments. Sirtuins (SIRT) are histone deacetylases that are involved in the regulation of redox and inflammatory homeostasis. Hence, the present study aims to investigate the role of SIRT-2 in modulating inflammation in a murine model of COPD.

Methods

COPD in mice was established by cigarette smoke (CS) exposure for 60 days, and AK-7 was used as the specific SIRT-2 inhibitor. AK-7 (100 µg/kg and 200 µg/kg body weight) was administered intranasally 1 h before CS exposure. Molecular docking was performed to analyze the binding affinity of different inflammatory proteins with AK-7.

Results

Immune cell analysis showed a significantly increased number of macrophages (F4/80), neutrophils (Gr-1), and lymphocytes (CD4+, CD8+, and CD19+) in the COPD, group and their population was declined by AK-7 administration. Total reactive oxygen species, total inducible nitric oxide synthase, inflammatory mediators such as neutrophil elastase, C-reactive protein, histamine, and cytokines as IL4, IL-6, IL-17, and TNF-α were elevated in COPD and declined in the AK-7 group. However, IL-10 showed reverse results representing anti-inflammatory potency. AK-7 administration by inhibiting SIRT-2 decreased the expression of p-NF-κB, p-P38, p-Erk, and p-JNK and increased the expression of Nrf-2. Furthermore, AK-7 also declined the lung injury by inhibiting inflammation, parenchymal destruction, emphysema, collagen, club cells, and Kohn pores. AK-7 also showed good binding affinity with inflammatory proteins.

Discussion

The current study reveals that SIRT-2 inhibition mitigates COPD severity and enhances pulmonary therapeutic interventions, suggesting AK-7 as a potential therapeutic molecule for COPD medication development.

HTR2B as a novel biomarker of chronic obstructive pulmonary disease with lung squamous cell carcinoma

Chronic obstructive pulmonary disease (COPD) is often associated with lung squamous cell carcinoma (LUSC), which has the same etiology (smoking, inflammation, oxidative stress, microenvironmental changes, and genetics). Smoking, inflammation, and airway remodeling are the most important and classical mechanisms of COPD comorbidity in LUSC patients. Cancer can occur during repeated airway damage and repair (airway remodeling). Changes in the inflammatory and immune microenvironments, which can cause malignant transformation of some cells, are currently being revealed in both LUSC and COPD patients. We obtained the GSE76925 dataset from the Gene Expression Omnibus database. Screening for possible COPD biomarkers was performed using the LASSO regression model and a random forest classifier. The compositional patterns of the immune cell fraction in COPD patients were determined using CIBERSORT. HTR2B expression was analyzed using validation datasets (GSE47460, GSE106986, and GSE1650). HTR2B expression in COPD cell models was determined via real-time quantitative PCR. Epithelial-mesenchymal transition (EMT) marker expression levels were determined after knocking down or overexpressing HTR2B. HTR2B function and mechanism in LUSC were analyzed with the Kaplan‒Meier plotter database. HTR2B expression was inhibited to detect changes in LUSC cell proliferation. A total of 1082 differentially expressed genes (DEGs) were identified in the GSE76925 dataset (371 genes were significantly upregulated, and 711 genes were significantly downregulated). Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that the DEGs were mainly enriched in the p53 signaling and β-alanine metabolism pathways. Gene Ontology enrichment analysis indicated that the DEGs were largely related to transcription initiation from the RNA polymerase I promoter and to the regulation of mononuclear cell proliferation. The LASSO regression model and random forest classifier results revealed that HTR2B, DPYS, FRY, and CD19 were key COPD genes. Immune cell infiltration analysis indicated that these genes were closely associated with immune cells. Analysis of the validation sets suggested that HTR2B was upregulated in COPD patients. HTR2B was significantly upregulated in COPD cell models, and its upregulation was associated with increased EMT marker expression. Compared with that in bronchial epithelial cells, HTR2B expression was upregulated in LUSC cells, and inhibiting HTR2B expression led to the inhibition of LUSC cell proliferation. In conclusions, HTR2B might be a new biomarker and therapeutic target in COPD patients with LUSC.

Effect of photobiomodulation in the balance between effector and regulatory T cells in an experimental model of COPD

Introduction

Currently, Chronic Obstructive Pulmonary Disease (COPD) has a high impact on morbidity and mortality worldwide. The increase of CD4+, CD8+ cells expressing NF-κB, STAT4, IFN-γ and perforin are related to smoking habit, smoking history, airflow rate, obstruction and pulmonary emphysema. Furthermore, a deficiency in CD4+CD25+Foxp3+ regulatory T cells (Tregs) may impair the normal function of the immune system and lead to respiratory immune disease. On the other hand, the anti-inflammatory cytokine IL-10, produced by Treg cells and macrophages, inhibits the synthesis of several pro-inflammatory cytokines that are expressed in COPD. Therefore, immunotherapeutic strategies, such as Photobiomodulation (PBM), aim to regulate the levels of cytokines, chemokines and transcription factors in COPD. Consequently, the objective of this study was to evaluate CD4+STAT4 and CD4+CD25+Foxp3+ cells as well as the production of CD4+IFN- γ and CD4+CD25+IL-10 in the lung after PBM therapy in a COPD mice model.

Methods

We induced COPD in C57BL/6 mice through an orotracheal application of cigarette smoke extract. PMB treatment was applied for the entire 7 weeks and Bronchoalveolar lavage (BAL) and lungs were collected to study production of IFN- γ and IL-10 in the lung. After the last administration with cigarette smoke extract (end of 7 weeks), 24 h later, the animals were euthanized. One-way ANOVA followed by NewmanKeuls test were used for statistical analysis with significance levels adjusted to 5% (p < 0.05).

Results

This result showed that PBM improves COPD symptomatology, reducing the number of inflammatory cells (macrophages, neutrophils and lymphocytes), the levels of IFN-γ among others, and increased IL-10. We also observed a decrease of collagen, mucus, bronchoconstriction index, alveolar enlargement, CD4+, CD8+, CD4+STAT4+, and CD4+IFN-γ+ cells. In addition, in the treated group, we found an increase in CD4+CD25+Foxp3+ and CD4+IL-10+ T cells.

Conclusion

This study suggests that PBM treatment could be applied as an immunotherapeutic strategy for COPD.

Dissecting causal relationships between immune cells, plasma metabolites, and COPD: a mediating Mendelian randomization study

Objective

This study employed Mendelian Randomization (MR) to investigate the causal relationships among immune cells, COPD, and potential metabolic mediators.

Methods

Utilizing summary data from genome-wide association studies, we analyzed 731 immune cell phenotypes, 1,400 plasma metabolites, and COPD. Bidirectional MR analysis was conducted to explore the causal links between immune cells and COPD, complemented by two-step mediation analysis and multivariable MR to identify potential mediating metabolites.

Results

Causal relationships were identified between 41 immune cell phenotypes and COPD, with 6 exhibiting reverse causality. Additionally, 21 metabolites were causally related to COPD. Through two-step MR and multivariable MR analyses, 8 cell phenotypes were found to have causal relationships with COPD mediated by 8 plasma metabolites (including one unidentified), with 1-methylnicotinamide levels showing the highest mediation proportion at 26.4%.

Conclusion

We have identified causal relationships between 8 immune cell phenotypes and COPD, mediated by 8 metabolites. These findings contribute to the screening of individuals at high risk for COPD and offer insights into early prevention and the precocious diagnosis of Pre-COPD.

Inflammation as the nexus: exploring the link between acute myocardial infarction and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), particularly following acute exacerbations (AE-COPD), significantly heightens the risks and mortality associated with acute myocardial infarction (AMI). The intersection of COPD and AMI is characterised by a considerable overlap in inflammatory mechanisms, which play a crucial role in the development of both conditions. Although extensive research has been conducted on individual inflammatory pathways in AMI and COPD, the understanding of thrombo-inflammatory crosstalk in comorbid settings remains limited. The effectiveness of various inflammatory components in reducing AMI infarct size or slowing COPD progression has shown promise, yet their efficacy in the context of comorbidity with COPD and AMI is not established. This review focuses on the critical importance of both local and systemic inflammation, highlighting it as a key pathophysiological connection between AMI and COPD/AE-COPD.

Coinfection with influenza virus and non-typeable Haemophilus influenzae aggregates inflammatory lung injury and alters gut microbiota in COPD mice

Background

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is associated with high mortality rates. Viral and bacterial coinfection is the primary cause of AECOPD. How coinfection with these microbes influences host inflammatory response and the gut microbiota composition is not entirely understood.

Methods

We developed a mouse model of AECOPD by cigarette smoke exposure and sequential infection with influenza H1N1 virus and non-typeable Haemophilus influenzae (NTHi). Viral and bacterial titer was determined using MDCK cells and chocolate agar plates, respectively. The levels of cytokines, adhesion molecules, and inflammatory cells in the lungs were measured using Bio-Plex and flow cytometry assays. Gut microbiota was analyzed using 16S rRNA gene sequencing. Correlations between cytokines and gut microbiota were determined using Spearman’s rank correlation coefficient test.

Results

Coinfection with H1N1 and NTHi resulted in more severe lung injury, higher mortality, declined lung function in COPD mice. H1N1 enhanced NTHi growth in the lungs, but NTHi had no effect on H1N1. In addition, coinfection increased the levels of cytokines and adhesion molecules, as well as immune cells including total and M1 macrophages, neutrophils, monocytes, NK cells, and CD4 + T cells. In contrast, alveolar macrophages were depleted. Furthermore, coinfection caused a decline in the diversity of gut bacteria. Muribaculaceae, Lactobacillus, Akkermansia, Lachnospiraceae, and Rikenella were further found to be negatively correlated with cytokine levels, whereas Bacteroides was positively correlated.

Conclusion

Coinfection with H1N1 and NTHi causes a deterioration in COPD mice due to increased lung inflammation, which is correlated with dysbiosis of the gut microbiota.