T-regulatory cells and programmed death 1+ T cells contribute to effector T-cell dysfunction in patients with chronic obstructive pulmonary disease

Granzyme B May Act as an Effector Molecule to Control the Inflammatory Process in COPD

Chronic obstructive pulmonary disease (COPD) is caused by smoking, but only a small proportion of smokers have disease severe enough to develop COPD. COPD is not always progressive. The question then arises as to what explains the different trajectories of COPD. The role of autoimmunity and regulatory T (Treg) cells in the pathogenesis of COPD is increasingly being recognized. Nine published studies on Treg cells in the lung tissue or bronchoalveolar lavage fluid have shown that smokers with COPD have fewer Treg cells than smokers without COPD or nonsmokers. Three studies showed a positive correlation between Treg cell count and FEV1%, suggesting an important role for Treg cells in COPD progression. Treg cells can regulate immunological responses via the granzyme B (GzmB) pathway. Immunohistochemical staining for GzmB in surgically resected lungs with centrilobular emphysema showed that the relationship between the amount of GzmB+ cells and FEV1% was comparable to that between Treg cell count and FEV1% in the COPD lung, suggesting that GzmB could be a functional marker for Treg cells. The volume fraction of GzmB+  cells in the small airways, the number of alveolar GzmB+ cells, and GzmB expression measured by enzyme-linked immunosorbent assay in the lung tissue of smokers were significantly correlated with FEV1%. These results suggest that the GzmB content in lung tissue may determine the progression of COPD by acting as an effector molecule to control inflammatory process. Interventions to augment GzmB-producing immunosuppressive cells in the early stages of COPD could help prevent or delay COPD progression.

Impairment of Gal-9 and Tim-3 crosstalk between Tregs and Th17 cells drives tobacco smoke-induced airway inflammation

Overexpression of T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) on T cells has been observed in smokers. However, whether and how galectin-9 (Gal-9)/TIM-3 signal between T-regulatory cells (Tregs) and type 17 helper (Th17) cells contributes to tobacco smoke-induced airway inflammation remains unclear. Here, we aimed to explore the role of the Gal-9/TIM-3 signal between Tregs and Th17 cells during chronic tobacco smoke exposure. Tregs phenotype and the expression of TIM-3 on CD4+ T cells were detected in a mouse model of experimental emphysema. The role of TIM-3 in CD4+ T cells was explored in a HAVCR2-/- mouse model and in mice that received recombinant anti-TIM3. The crosstalk between Gal-9 and Tim-3 was evaluated by coculture Tregs with effector CD4+ T cells. We also invested the expression of Gal-9 in Tregs in patients with COPD. Our study revealed that chronic tobacco smoke exposure significantly reduces the frequency of Tregs in the lungs of mice and remarkably shapes the heterogeneity of Tregs by downregulating the expression of Gal-9. We observed a pro-inflammatory but restrained phenotypic transition of CD4+ T cells after tobacco smoke exposure, which was maintained by TIM-3. The restrained phenotype of CD4+ T cells was perturbed when TIM-3 was deleted or neutralised. Tregs from the lungs of mice with emphysema displayed a blunt ability to inhibit the differentiation and proliferation of Th17 cells. The inhibitory function of Tregs was partially restored by using recombinant Gal-9. The interaction between Gal-9 and TIM-3 inhibits the differentiation of Th17 cells and promotes apoptosis of CD4+ T cells, possibly by interfering with the expression of retinoic acid receptor-related orphan receptor gamma t. The expression of Gal-9 in Tregs was reduced in patients with COPD, which was associated with Th17 response and lung function. These findings present a new paradigm that impairment of Gal-9/Tim-3 crosstalk between Tregs and Th17 cells during chronic tobacco smoke exposure promotes tobacco smoke-induced airway/lung inflammation.

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.

The clinical association of programmed death-1/PD-L1 axis, myeloid derived suppressor cells subsets and regulatory T cells in peripheral blood of stable COPD patients

Background

Myeloid-derived suppressor cells (MDSCs) have crucial immunosuppressive role in T cell dysfunction in various disease processes. However, the role of MDSCs and their impact on Tregs in COPD have not been fully understood. The aim of the present study is to investigate the immunomodulatory role of MDSCs and their potential impact on the expansion and function of Tregs in COPD patients.

Methods

Peripheral blood samples were collected to analyze circulating MDSCs, Tregs, PD-1/PD-L1 expression to assess the immunomodulatory role of MDSC and their potential impact on the expansion and function of Treg in COPD. A total of 54 COPD patients and 24 healthy individuals were enrolled in our study. Flow cytometric analyses were performed to identify granulocytic MDSCs (G-MDSCs), monocytic MDSCs (M-MDSCs), Tregs, and the expression of PD-1/PD-L1(L2) on MDSCs and Tregs in peripheral blood.

Results

Our results revealed a significantly higher percentage of G-MDSCs and M-MDSCs (p < 0.001) in COPD patients compared to the healthy controls. Additionally, a significantly higher proportion of peripheral blood Tregs was observed in COPD patients. Furthermore, an increased expression of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) on Tregs (p < 0.01) was detected in COPD patients. The expression of PD-1 on CD4+ Tcells and Tregs, but not CD8+Tcells, was found to be increased in patients with COPD compared to controls. Furthermore, an elevated expression of PD-L1 on M-MDSCs (p < 0.01) was also observed in COPD patients. A positive correlation was observed between the accumulation of M-MDSCs and Tregs in COPD patients. Additionally, the percentage of circulating M-MDSCs is positively associated with the level of PD-1 (r = 0.51, p < 0.0001) and CTLA-4 (r = 0.42, p = 0.0014) on Tregs in COPD.

Conclusion

The recruitment of MDSCs, accumulation of Tregs, and up-regulation of CTLA-4 on Treg in COPD, accompanied by an increased level of PD-1/PD-L1, suggest PD-1/PD-L1 axis may be potentially involved in MDSCs-induced the expansion and activation of Treg at least partially in COPD.

Th17/Treg balance: the bloom and wane in the pathophysiology of sepsis

Sepsis is a multi-organ dysfunction characterized by an unregulated host response to infection. It is associated with high morbidity, rapid disease progression, and high mortality. Current therapies mainly focus on symptomatic treatment, such as blood volume supplementation and antibiotic use, but their effectiveness is limited. Th17/Treg balance, based on its inflammatory property, plays a crucial role in determining the direction of the inflammatory response and the regression of organ damage in sepsis patients. This review provides a summary of the changes in T-helper (Th) 17 cell and regulatory T (Treg) cell differentiation and function during sepsis, the heterogeneity of Th17/Treg balance in the inflammatory response, and the relationship between Th17/Treg balance and organ damage. Th17/Treg balance exerts significant control over the bloom and wanes in host inflammatory response throughout sepsis.

The analysis of multiple omics and examination of pathological images revealed the prognostic and therapeutic significances of CD93 in lung squamous cell carcinoma

As a potent pro-angiogenic factor, the role of CD93 in the prognosis and therapeutic outcomes of lung squamous cell carcinoma (LUSC) merits exploration. In this study, we systematically collected transcriptomic, genomic, and clinical data from various public databases, as well as pathological images from hospital-operated patients. Employing statistical analysis software like R (Version 4.2.2) and GraphPad (Version 8.0), we conducted comprehensive analyses of multi-omics data. The results revealed elevated CD93 expression in LUSC tissues, closely associated with various cancer-related pathways. High CD93 expression indicated advanced clinical stage and poorer prognosis. Furthermore, CD93 contributed to resistance against chemotherapy and immunotherapy by enhancing tumor cell stemness, reducing immune cell infiltration, and inducing T cell exhaustion. Patients with low CD93 expression exhibited higher response rates to both chemotherapy and immunotherapy. Immunohistochemistry validated the significance of CD93 in LUSC. CD93 emerges as a biomarker signaling unfavorable prognosis and influencing therapeutic outcomes, suggesting a potential LUSC treatment avenue.

Reported side-effects following Oxford/AstraZeneca COVID-19 vaccine in the north-west province, Iran: A cross-sectional study

While the vaccination was introduced as a promising tool to control the Coronavirus disease 2019 (COVID-19) pandemic, concerns about vaccine-related side effects had grown. Due to the widespread administration of the COVID-19 vaccine worldwide for the first time, it was necessary to evaluate the safety and potential side effects in recipients. This study aims to assess, the incidence of adverse effects following Oxford-AstraZeneca vaccination and identify their related factors. In this cross-sectional survey-based study, 453 volunteers participated, including 235 men and 218 women. The reported adverse reactions from recipients of the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccine were collected by using a questionnaire. The findings showed that the incidence of adverse reactions, such as neurological, systematic, gastrointestinal, respiratory, and local symptoms were significantly higher after the first dose compared to the second dose. Systematic symptoms were the most prevalent reported side effects after the first and second dose injection. The demographical study of participants showed that individuals aged 18-34 and females were more prone to present adverse events following vaccination. However, no significant relationship was found between the occurrence of side effects and the recipients' body mass index. Despite the life-saving role of vaccination against SARS-CoV-2, it may have some adverse reactions in recipients. The severity and frequency of side effects were different. So, they were dependent on several factors, including gender and age. Altogether, post-vaccination adverse reactions were mild and tolerable.

Identification of Potential Differentially-Methylated/Expressed Genes in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease that causes obstructed airflow from the lungs. DNA methylation can regulate gene expression. Understanding the potential molecular mechanism of COPD is of great importance. The aim of this study was to find differentially methylated/expressed genes in COPD. DNA methylation and gene expression profiles in COPD were downloaded from the dataset, followed by functional analysis of differentially-methylated/expressed genes. The potential diagnostic value of these differentially-methylated/expressed genes was determined by receiver operating characteristic (ROC) analysis. Expression validation of differentially-methylated/expressed genes was performed by in vitro experiment and extra online datasets. Totally, 81 hypermethylated-low expression genes and 121 hypomethylated-high expression genes were found in COPD. Among which, 9 core hypermethylated-low expression genes (CD247, CCR7, CD5, IKZF1, SLAMF1, IL2RB, CD3E, CD7 and IL7R) and 8 core hypomethylated-high expression genes (TREM1, AQP9, CD300LF, CLEC12A, NOD2, IRAK3, NLRP3 and LYZ) were identified in the protein-protein interaction (PPI) network. Moreover, these genes had a potential diagnostic utility for COPD. Some signaling pathways were identified in COPD, including T cell receptor signaling pathway, cytokine-cytokine receptor interaction, hematopoietic cell lineage, HTLV-I infection, endocytosis and Jak-STAT signaling pathway. In conclusion, differentially-methylated/expressed genes and involved signaling pathways are likely to be associated with the process of COPD.

Adverse Effects Reported and Insights Following Sinopharm COVID-19 Vaccination

Vaccines are promising strategies for controlling COVID-19; however, COVID-19 vaccine side effects play a central role in public confidence in the vaccine and its uptake process. This study aimed to provide evidence on the post-vaccination early side effects of the BBIBP-CorV (Sinopharm) vaccine. This cross-sectional survey-based study was conducted between November 2021 and January 2022 among recipients of the BBIBP-CorV vaccine, using a questionnaire-based survey. Our final sample consisted of 657 participants, including 392 women. Among the study cases, only 103 (15.7%) participants received one dose of vaccine, and the rest received both doses (N = 554, 84.3%). Systemic symptoms (first dose: N = 187, both doses: N = 128) were the most commonly reported events after vaccination, and among them, injection site pain (first dose: 19.3%, both doses: 12.9%) was the most prevalent adverse effect. All reporting events were mild and resolved in less than 3 days without hospitalization. Among the participants, females and young people aged 35-65 were more prone to manifest side effects (N = 169, 53.3%) after the vaccine injection. Furthermore, our results revealed that the recipients who were suffering from underlying diseases, including diabetes, renal disorder, and respiratory illness, reported fewer adverse responses after vaccination in comparison with healthy individuals. Vaccination against SARS-CoV-2 may lead to some adverse reactions in recipients. However, the frequency of post-vaccination early side effects differed in people, but all responses were slight and temporary.

Cigarette Smoking Contributes to Th1/Th2 Cell Dysfunction via the Cytokine Milieu in Chronic Obstructive Pulmonary Disease

Background

Dysregulation and pyroptosis of T-helper (Th) cells and inflammatory cytokines have been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the immune response mechanisms as a consequence of tobacco smoke exposure are not fully understood. We hypothesized that cigarette smoke-induced inflammation could be modulated through the cytokine milieu and T-cell nicotinic acetylcholine receptors (nAChRs).

Methods

The proportions of peripheral blood Th1 and Th2 cells from patients with COPD, smokers without airway obstruction and healthy nonsmokers were analyzed using flow cytometry. The levels of plasma proinflammatory cytokines and their potential association with pulmonary function were also measured. The influence of cigarette smoke extract (CSE) on the conditioned differentiation of T helper cell subsets was further examined in vitro.

Results

Significantly higher Th1 cell and plasma IFN-γ and IL-18 levels but lower levels of Th2 cells were found in the peripheral blood from patients with COPD. The increased plasma levels of IFN-γ and IL-18 were negatively correlated with pulmonary function (FEV1% predicted value). Pyroptosis participates in COPD development probably through the activation of the NLRP3 inflammasome upon exposure to CSE. CSE does not directly induce the differentiation of T helper cells; however, under conditioned medium, CSE promotes Th1 development through α7 nAChR modification, while it does not substantially interfere with Th2 differentiation.

Conclusion

The differences in the cytokine milieu play a key role in the effects of CSE on the immune response in patients with COPD.

Decreased programmed cell death ligand 2-positive monocytic myeloid-derived suppressor cells and programmed cell death protein 1-positive T-regulatory cells in patients with type 2 diabetes: implications for immunopathogenesis

Objectives

The activation of immune cells plays a significant role in the progression of type 2 diabetes. This study aimed to investigate the potential role of myeloid-derived suppressor cells (MDSCs) and T-regulatory cells (Tregs) in type 2 diabetes.

Methods

A total of 61 patients diagnosed with type 2 diabetes were recruited. Clinical characteristics were reviewed and peripheral blood samples were collected. We calculated the percentage of different cells. Frequencies of MDSC subsets refered to the percentage of G-MDSCs (CD15+CD33+CD11b+CD14-HLA-DR-/low) in CD45 positive cells and the percentage of M-MDSCs (CD14+CD15-CD11b+CD33+HLA-DR-/low) in lymphocytes plus monocytes.

Results

Frequencies of programmed cell death ligand 1-positive granulocytic MDSCs (PD-L1+ G-MDSCs), programmed cell death ligand 2-positive monocytic MDSCs (PD-L2+ M-MDSCs), PD-L2+ G-MDSC, and programmed cell death protein 1-positive Tregs (PD-1+Tregs) were decreased in patients with type 2 diabetes. The frequency of PD-1+ Tregs was positively related to PD-L2+ M-MDSCs (r= 0.357, P = 0.009) and negatively related to HbA1c (r = -0.265, P = 0.042), fasting insulin level (r = -0.260, P = 0.047), and waist circumference (r = -0.373, P = 0.005).

Conclusions

Decreased PD-L2+ M-MDSCs and PD-1+ Tregs may promote effector T cell activation, leading to chronic low-grade inflammation in type 2 diabetes. These findings highlight the contribution of MDSCs and Tregs to the immunopathogenesis of type 2 diabetes and suggest their potential as targets for new therapeutic approaches.

Phenotypic Profiling of Immune Cells and Their Mediators in Chronic Obstructive Pulmonary Disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an inflammatory disorder and has been proposed to have an imbalance between pro-inflammatory and anti-inflammatory factors.

METHODS

This study was conducted on 41 participants {18 COPD patients (smokers, COPD S (n = 9); reformed smokers, COPD RS (n = 9)) and 23 controls (non-smokers, CNS (n = 14); smokers, CS (n = 9))}. Flow cytometry was used to identify circulatory immune cells and correlated with serum cytokines.

RESULTS

On comparison, significantly lower frequency of CD3+ T cells were observed in COPD S as compared to CNS (p < 0.01) and CS (p < 0.01); CD4+ T cells were lower in COPD S (p < 0.05), COPD RS (p < 0.05) and CNS (p < 0.01) as compared to CS. CD8+ T cells were elevated in COPD S as compared to CS (p < 0.05). Lower frequency of cDCs were observed in COPD S as compared to CS (p < 0.05) and COPD RS as compared to CNS (p < 0.01) and CS (p < 0.01). Lower frequency of pDCs were observed in COPD RS as compared to COPD S (p < 0.05), CNS (p < 0.05) and CS (p < 0.01). Lower frequency of Tregs was observed in COPD S as compared to CNS (p < 0.05) and CS (p < 0.05).

CONCLUSIONS

Characteristic changes observed indicate a significant impact of immune cells in the progression of the disease.

Immunoprofiling bronchoalveolar lavage cells reveals multifaceted smoking-associated immune dysfunction

Background

Bronchoalveolar lavage (BAL) is an underutilised tool in the search for pulmonary disease biomarkers. While leukocytes with effector and suppressor function play important roles in airway immunity and tumours, it remains unclear if frequencies and phenotypes of BAL leukocytes can be useful parameters in lung cancer studies and clinical trials. We therefore explored the utility of BAL leukocytes as a source of biomarkers interrogating the impact of smoking, a major lung cancer risk determinant, on pulmonary immunity.

Methods

In this "test case" observational study, BAL samples from 119 donors undergoing lung cancer screening and biopsy procedures were evaluated by conventional and spectral flow cytometry to exemplify the comprehensive immune analyses possible with this biospecimen. Proportions of major leukocyte populations and phenotypic markers levels were found. Multivariate linear rank sum analysis considering age, sex, cancer diagnosis and smoking status was performed.

Results

Significantly increased frequencies of myeloid-derived suppressor cells and PD-L1-expressing macrophages were found in current and former smokers compared to never-smokers. While cytotoxic CD8 T-cells and conventional CD4 helper T-cell frequencies were significantly reduced in current and former smokers, expression of immune checkpoints PD-1 and LAG-3 as well as Tregs proportions were increased. Lastly, the cellularity, viability and stability of several immune readouts under cryostorage suggested BAL samples are useful for correlative end-points in clinical trials.

Conclusions

Smoking is associated with heightened markers of immune dysfunction, readily assayable in BAL, that may reflect a permissive environment for cancer development and progression in the airway.

Immunosuppression by Inflammation-Stimulated Amplification of Myeloid-Derived Suppressor Cells and Changes in Expression of Immune Checkpoint HHLA2 in Chronic Obstructive Pulmonary Disease

Background

The interaction between immune checkpoint and myeloid-derived suppressor cells (MDSCs) play a significant role in inflammatory diseases. But their correlation with chronic obstructive pulmonary disease (COPD) remains unclear.

Methods

The differentially expressed immune checkpoints and immunocytes in the airway tissues of COPD patients were identified by bioinformatics analysis, followed by correlation analysis and identification of immune-related differential genes for Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis. The results of bioinformatics analysis were verified by ELISA and Real-Time PCR and transcriptome sequencing of the peripheral blood of both COPD patients and healthy subjects.

Results

The results of the bioinformatics analysis showed that the level of MDSCs in airway tissue and peripheral blood of COPD patients was higher than that of healthy controls. The expression of CSF1 in airway tissue and peripheral blood of COPD patients increased, and CYBB was increased in airway tissue and decreased in peripheral blood of COPD patients. The expression of HHLA2 in the airway tissue decreased in COPD patients, and showed a negative correlation with MDSCs, with a correlation coefficient of -0.37. The peripheral blood flow cytometry results indicated that MDSCs and Treg cells of COPD patients were higher than those in the healthy control group. The results of peripheral blood ELISA and RT-PCR showed that the HHLA2 and CSF1 levels in COPD patients were higher than those in the healthy control group.

Conclusion

In COPD, the bone marrow is stimulated to produce MDSCs, and a large number of MDSCs migrate to airway tissue through peripheral blood and cooperate with HHLA2 to exert an immunosuppressive effect. Whether MDSCs play an immunosuppressive effect during migration needs to be further confirmed.

The Influence of Comorbidities on Chemokine and Cytokine Profile in Obstructive Sleep Apnea Patients: Preliminary Results

INTRODUCTION

Obstructive sleep apnea (OSA) is frequently associated with a chronic inflammatory state and cardiovascular/metabolic complications. The aim of this study was to evaluate the influence of certain comorbidities on a panel of 45 chemokines and cytokines in OSA patients with special regard to their possible association with cardiovascular diseases.

MATERIAL AND METHODS

This cross-sectional study was performed on 61 newly diagnosed OSA patients. For the measurement of the plasma concentration of chemokines and cytokines, the magnetic bead-based multiplex assay for the Luminex^® platform was used.

RESULTS

In the patients with concomitant COPD, there were increased levels of pro-inflammatory cytokines (CCL11, CD-40 ligand) and decreased anti-inflammatory cytokine (IL-10), while in diabetes, there were increased levels of pro-inflammatory cytokines (IL-6, TRIAL). Obesity was associated with increased levels of both pro-inflammatory (IL-13) and anti-inflammatory (IL-1RA) cytokines. Hypertension was associated with increased levels of both pro-inflammatory (CCL3) and anti-inflammatory (IL-10) cytokines. Increased daytime pCO₂, low mean nocturnal SaO₂, and the oxygen desaturation index were associated with increased levels of pro-inflammatory cytokines (CXCL1, PDGF-AB, TNF-α, and IL-15).

CONCLUSIONS

In OSA patients with concomitant diabetes and COPD, elevated levels of certain pro-inflammatory and decreased levels of certain anti-inflammatory cytokines may favor the persistence of a chronic inflammatory state with further consequences. Nocturnal hypoxemia, frequent episodes of desaturation, and increased daytime pCO₂ are factors contributing to the chronic inflammatory state in OSA patients.

Similar programmed death ligand 1 (PD-L1) expression profile in patients with mild COPD and lung cancer

Programmed Death Ligand 1 (PD-L1) is crucial in regulating the immunological tolerance in non-small cell lung cancer (NSCLC). Alveolar macrophage (AM)-derived PD-L1 binds to its receptor, PD-1, on surveilling lymphocytes, leading to lymphocyte exhaustion. Increased PD-L1 expression is associated with cigarette smoke (CS)-exposure. However, the PD-L1 role in CS-associated lung diseases associated with NSCLC, such as chronic obstructive pulmonary disease (COPD), is still unclear. In two different cohorts of ever smokers with COPD or NSCLC, and ever and never smoker controls, we evaluated PD-L1 expression: (1) via cutting-edge digital spatial proteomic and transcriptomic profiling (Geomx) of formalin-fixed paraffin-embedded (FFPE) lung tissue sections (n = 19); and (2) via triple immunofluorescence staining of bronchoalveolar lavage (BAL) AMs (n = 83). PD-L1 mRNA expression was also quantified in BAL AMs exposed to CS extract. PD-L1 expression was increased in the bronchiolar wall, parenchyma, and vascular wall from mild-moderate (GOLD 1-2) COPD patients compared to severe-very severe (GOLD 3-4) COPD patients and controls. Within all the COPD patients, PD-L1 protein expression was associated with upregulation of genes involved in tumor progression and downregulation of oncosuppressive genes, and strongly directly correlated with the FEV₁% predicted, indicating higher PD-L1 expression in the milder vs. more severe COPD stages. In bronchioles, PD-L1 levels were strongly directly correlated with the number of functionally active AMs. In BAL, we confirmed that AMs from patients with both GOLD 1-2 COPD and NSCLC had the highest and similar, PD-L1 expression levels versus all the other groups, independently from active cigarette smoking. Intriguingly, AMs from patients with more severe COPD had reduced AM PD-L1 expression compared to patients with mild COPD. Acute CS extract stimulation increased PD-L1 mRNA expression only in never-and not in ever-smoker AMs. Lungs from patients with mild COPD and NSCLC are characterized by a similar strong PD-L1 expression signature in bronchioles and functionally active AMs compared to patients with severe COPD and controls. Active smoking does not affect PD-L1 levels. These observations represent a new resource in understanding the innate immune mechanisms underlying the link between COPD and lung cancer onset and progression and pave the way to future studies focused on the mechanisms by which CS promotes tumorigenesis and COPD.

Lung cancer patients with chronic obstructive pulmonary disease benefit from anti-PD-1/PD-L1 therapy

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are two of the most fatal respiratory diseases, seriously threatening human health and imposing a heavy burden on families and society. Although COPD is a significant independent risk factor for LC, it is still unclear how COPD affects the prognosis of LC patients, especially when LC patients with COPD receive immunotherapy. With the development of immune checkpoint inhibition (ICI) therapy, an increasing number of inhibitors of programmed cell death-1 (PD-1) and PD-1 ligand (PD-L1) have been applied to the treatment of LC. Recent studies suggest that LC patients with COPD may benefit more from immunotherapy. In this review, we systematically summarized the outcomes of LC patients with COPD after anti-PD-1/PD-L1 treatment and discussed the tumor immune microenvironment (TIME) regulated by COPD in LC immunotherapy, which provides novel insights for the clinical treatment of LC patients with COPD.

GATA3/long noncoding RNA MHC-R regulates the immune activity of dendritic cells in chronic obstructive pulmonary disease induced by air pollution particulate matter

Chronic obstructive pulmonary disease (COPD) is a heterogeneous illness associated with aberrant inflammatory immune reaction in the lung in response to noxious particles and gases. Our previous epidemiological studies discovered that long-term exposure to air pollution PM was associated with an increase in the incidence of COPD and lung function decline, but the impact of air pollution on the onset of COPD and its pathogenesis remains obscure. In recent years, long noncoding RNAs (lncRNAs) have been documented to have a crucial role in COPD. Our preliminary study found that the expression of lncRNA MHC-R in the lung tissues of rats exposed to air pollution PM was dramatically elevated, and the specific expression was mainly focused on the immune-related MHC I, antigen-presenting, and adaptive immune response. After transcription factor prediction, it was found that GATA3 could be combined with the specific sequence of the lncRNA MHC-R promoter region. Dendritic cells (DCs) are necessary antigen-presenting cells (APCs) with the most potent antigen-presenting function. We proved that GATA3/lncRNA MHC-R might regulate the immune activities of DCs to participate in the pathogenic mechanism of COPD induced by air pollution PM, which opens up a new way for early COPD diagnosis and treatment.

No smoke without fire: the impact of cigarette smoking on the immune control of tuberculosis

Cigarette smoke (CS) exposure is a key risk factor for both active and latent tuberculosis (TB). It is associated with delayed diagnosis, more severe disease progression, unfavourable treatment outcomes and relapse after treatment. Critically, CS exposure is common in heavily populated areas with a high burden of TB, such as China, India and the Russian Federation. It is therefore prudent to evaluate interventions for TB while taking into account the immunological impacts of CS exposure. This review is a mechanistic examination of how CS exposure impairs innate barrier defences, as well as alveolar macrophage, neutrophil, dendritic cell and T-cell functions, in the context of TB infection and disease.

Role of myeloid-derived suppressor cells in viral respiratory infections; Hints for discovering therapeutic targets for COVID-19

The expansion of myeloid-derived suppressor cells (MDSCs), known as heterogeneous population of immature myeloid cells, is enhanced during several pathological conditions such as inflammatory or viral respiratory infections. It seems that the way MDSCs behave in infection depends on the type and the virulence mechanisms of the invader pathogen, the disease stage, and the infection-related pathology. Increasing evidence showing that in correlation with the severity of the disease, MDSCs are accumulated in COVID-19 patients, in particular in those at severe stages of the disease or ICU patients, contributing to pathogenesis of SARS-CoV2 infection. Based on the involved subsets, MDSCs delay the clearance of the virus through inhibiting T-cell proliferation and responses by employing various mechanisms such as inducing the secretion of anti-inflammatory cytokines, inducible nitric oxide synthase (iNOS)-mediated hampering of IFN-γ production, or forcing arginine shortage. While the immunosuppressive characteristic of MDSCs may help to preserve the tissue homeostasis and prevent hyperinflammation at early stages of the infection, hampering of efficient immune responses proved to exert significant pathogenic effects on severe forms of COVID-19, suggesting the targeting of MDSCs as a potential intervention to reactivate T-cell immunity and thereby prevent the infection from developing into severe stages of the disease. This review tried to compile evidence on the roles of different subsets of MDSCs during viral respiratory infections, which is far from being totally understood, and introduce the promising potential of MDSCs for developing novel diagnostic and therapeutic approaches, especially against COVID-19 disease.

Mechanisms, Pathophysiology and Currently Proposed Treatments of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is one of the leading global causes of morbidity and mortality. A hallmark of COPD is progressive airflow obstruction primarily caused by cigarette smoke (CS). CS exposure causes an imbalance favoring pro- over antioxidants (oxidative stress), leading to transcription factor activation and increased expression of inflammatory mediators and proteases. Different cell types, including macrophages, epithelial cells, neutrophils, and T lymphocytes, contribute to COPD pathophysiology. Alteration in cell functions results in the generation of an oxidative and inflammatory microenvironment, which contributes to disease progression. Current treatments include inhaled corticosteroids and bronchodilator therapy. However, these therapies do not effectively halt disease progression. Due to the complexity of its pathophysiology, and the risk of exacerbating symptoms with existing therapies, other specific and effective treatment options are required. Therapies directly or indirectly targeting the oxidative imbalance may be promising alternatives. This review briefly discusses COPD pathophysiology, and provides an update on the development and clinical testing of novel COPD treatments.

COPD, Pulmonary Fibrosis and ILAs in Aging Smokers: The Paradox of Striking Different Responses to the Major Risk Factors

Aging and smoking are associated with the progressive development of three main pulmonary diseases: chronic obstructive pulmonary disease (COPD), interstitial lung abnormalities (ILAs), and idiopathic pulmonary fibrosis (IPF). All three manifest mainly after the age of 60 years, but with different natural histories and prevalence: COPD prevalence increases with age to >40%, ILA prevalence is 8%, and IPF, a rare disease, is 0.0005–0.002%. While COPD and ILAs may be associated with gradual progression and mortality, the natural history of IPF remains obscure, with a worse prognosis and life expectancy of 2–5 years from diagnosis. Acute exacerbations are significant events in both COPD and IPF, with a much worse prognosis in IPF. This perspective discusses the paradox of the striking pathological and pathophysiologic responses on the background of the same main risk factors, aging and smoking, suggesting two distinct pathophysiologic processes for COPD and ILAs on one side and IPF on the other side. Pathologically, COPD is characterized by small airways fibrosis and remodeling, with the destruction of the lung parenchyma. By contrast, IPF almost exclusively affects the lung parenchyma and interstitium. ILAs are a heterogenous group of diseases, a minority of which present with the alveolar and interstitial abnormalities of interstitial lung disease.

Modulation of the PD-1/PD-L1 immune checkpoint axis during inflammation-associated lung tumorigenesis

Chronic obstructive pulmonary disease (COPD) is a significant risk factor for lung cancer. One potential mechanism through which COPD contributes to lung cancer development could be through generation of an immunosuppressive microenvironment that allows tumor formation and progression. In this study, we compared the status of immune cells and immune checkpoint proteins in lung tumors induced by the tobacco smoke carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) or NNK + lipopolysaccharide (LPS), a model for COPD-associated lung tumors. Compared with NNK-induced lung tumors, NNK+LPS-induced lung tumors exhibited an immunosuppressive microenvironment characterized by higher relative abundances of PD-1+ tumor-associated macrophages, PD-L1+ tumor cells, PD-1+ CD4 and CD8 T lymphocytes and FOXP3+ CD4 and CD8 T lymphocytes. Also, these markers were more abundant in the tumor tissue than in the surrounding 'normal' lung tissue of NNK+LPS-induced lung tumors. PD-L1 expression in lung tumors was associated with IFNγ/STAT1/STAT3 signaling axis. In cell line models, PD-L1 expression was found to be significantly enhanced in phorbol-12-myristate 13-acetate activated THP-1 human monocytes (macrophages) treated with LPS or incubated in conditioned media (CM) generated by non-small cell lung cancer (NSCLC) cells. Similarly, when NSCLC cells were incubated in CM generated by activated THP-1 cells, PD-L1 expression was upregulated in EGFR- and ERK-dependent manner. Overall, our observations indicate that COPD-like chronic inflammation creates a favorable immunosuppressive microenvironment for tumor development and COPD-associated lung tumors might show a better response to immune checkpoint therapies.

Impact of chronic obstructive pulmonary disease on immune checkpoint inhibitor efficacy in advanced lung cancer and the potential prognostic factors

Background

The coexistence of chronic obstructive pulmonary disease (COPD) in lung cancer patients often correlates with a poor clinical outcome regardless of tumor stage, mainly due to older age, poor lung function, and complex comorbid disease. Emerging data suggest that the pathogenesis of both diseases involves aberrant immune functioning. We conducted this retrospective study to describe the impact of COPD on the clinical outcomes of lung cancer patients treated with immunotherapy and investigate the potential prognostic factors.

Methods

In total, 156 patients with advanced-stage lung cancer who received at least one administration of an anti-programmed cell death 1 (PD-1)/anti-programmed cell death-ligand 1 (PD-L1) immune checkpoint inhibitor (ICI) at any treatment line at Zhongshan Hospital Fudan University between May 2018 and December 2019 were enrolled in our study. Overall survival (OS) and progression-free survival (PFS) were analyzed according to the presence of COPD. We also evaluated the prognostic value of circulating cytokine levels for clinical outcome.

Results

We found that the presence of COPD (both spirometry-based COPD and physician-defined COPD) was significantly associated with longer PFS (316 vs. 186 days, P=0.018). Moderate and severe COPD tended to have a better impact on the survival of these patients. In the present study, we reported that patients with mixed ventilatory defects tended to have a better OS (P=0.043) and PFS (P=0.18) when treated with ICIs compared to the normal lung function group. We also found that low baseline plasma interleukin (IL)-8 and IL-2 receptor (IL-2R) levels were associated with longer PFS in patients with advanced-stage lung cancer who received ICI treatment. Furthermore, patients who had increased IL-2R levels had significantly poorer OS [hazard ratio (HR) =3.63; 95% confidence interval (CI), 0.98–13.44; P=0.040] and PFS (HR =3.241; 95% CI, 1.032–10.18; P=0.035) when treated with ICIs. Nomograms were established based on the independent prognostic factors derived from our final multivariate models.

Conclusions

COPD was associated with better survival in advanced-stage lung cancer patients treated with ICIs. Plasma IL-8 and IL-2R levels were potential prognostic factors for clinical outcome. The nomograms represent a possibly useful tool for predicting the clinical outcomes of immunotherapy.

Blockade of PD-1 decreases neutrophilic inflammation and lung damage in experimental COPD

Chronic obstructive lung disease (COPD) and lung cancer are both caused by smoking and often occur as comorbidity. The programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) axis is an important canonic immunoregulatory pathway, and antibodies that specifically block PD-1 or PD-L1 have demonstrated efficacy as therapeutic agents for non-small cell lung cancer. The role of the PD-1/PD-L1 axis in the pathogenesis of COPD is unknown. Here, we analyzed the function of the PD-1/PD-L1 axis in preclinical COPD models and evaluated the concentrations of PD-1 and PD-L1 in human serum and bronchoalveolar lavage (BAL) fluids as biomarkers for COPD. Anti-PD-1 treatment decreased lung damage and neutrophilic inflammation in mice chronically exposed to cigarette smoke (CS) or nontypeable Haemophilus influenzae (NTHi). Ex vivo stimulated macrophages obtained from anti-PD-1-treated mice released reduced amounts of inflammatory cytokines. PD-L1 concentrations correlated positively with PD-1 concentrations in human serum and BAL fluids. Lung sections obtained from patients with COPD stained positive for PD-L1. Our data indicate that the PD-1/PD-L1 axis is involved in developing inflammation and tissue destruction in COPD. Inflammation-induced activation of the PD-1 pathway may contribute to disease progression.

The Role of Human Leukocyte Antigen-DR in Regulatory T Cells in Patients with Virus-Induced Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Background

This study assessed the role of different immune phenotypes of T cells in virus-induced acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Material/Methods

The study involved 103 participants, including individuals with virus-induced AECOPD (n=32), non-virus-induced AECOPD (n=31), and stable COPD (n=20) and individuals who were healthy smokers (n=20). The immune phenotypes of T cells in peripheral blood were evaluated via flow cytometry analysis, and the differences were analyzed.

Results

Patients with virus-induced AECOPD (virus group) had a higher COPD assessment test score on admission than those in the group with non-virus-induced AECOPD (nonvirus group; 25.6±3.8 vs 21.9±4.8, P=0.045). A lower CD4⁺ human leukocyte antigen-DR (HLA-DR)⁺ frequency was found in the peripheral blood of the virus group compared with the nonvirus group (2.2 vs 4.2, P=0.015), and the frequency of CD4⁺ CD25^high CD127^low HLA-DR⁺ in CD4⁺ in the virus group was lower than in the nonvirus group (1.1 vs 3.6, P=0.011). The CD3⁺, CD4⁺, CD8⁺, CD4⁺ central memory T cell, CD4⁺ effector memory T cell (Tem), CD4⁺ end-stage T cell, and CD8⁺ Tem levels in lymphocytes of peripheral blood were lower in exacerbation groups relative to those in the stable COPD and healthy smoking groups, but similar between exacerbation groups. Similar frequencies and levels of T cells between different stagings of COPD were also identified.

Conclusions

The expression of HLA-DR on the cell surface of CD4⁺ regulatory T cells (Tregs) was lower in the peripheral blood of patients with virus-induced AECOPD. The expression of HLA-DR in CD4⁺ Tregs suggested the effect of respiratory viruses on adaptive immunity of patients with AECOPD to some extent.

Tumour Microenvironment: Roles of the Aryl Hydrocarbon Receptor, O-GlcNAcylation, Acetyl-CoA and Melatonergic Pathway in Regulating Dynamic Metabolic Interactions across Cell Types-Tumour Microenvironment and Metabolism

This article reviews the dynamic interactions of the tumour microenvironment, highlighting the roles of acetyl-CoA and melatonergic pathway regulation in determining the interactions between oxidative phosphorylation (OXPHOS) and glycolysis across the array of cells forming the tumour microenvironment. Many of the factors associated with tumour progression and immune resistance, such as yin yang (YY)1 and glycogen synthase kinase (GSK)3β, regulate acetyl-CoA and the melatonergic pathway, thereby having significant impacts on the dynamic interactions of the different types of cells present in the tumour microenvironment. The association of the aryl hydrocarbon receptor (AhR) with immune suppression in the tumour microenvironment may be mediated by the AhR-induced cytochrome P450 (CYP)1b1-driven 'backward' conversion of melatonin to its immediate precursor N-acetylserotonin (NAS). NAS within tumours and released from tumour microenvironment cells activates the brain-derived neurotrophic factor (BDNF) receptor, TrkB, thereby increasing the survival and proliferation of cancer stem-like cells. Acetyl-CoA is a crucial co-substrate for initiation of the melatonergic pathway, as well as co-ordinating the interactions of OXPHOS and glycolysis in all cells of the tumour microenvironment. This provides a model of the tumour microenvironment that emphasises the roles of acetyl-CoA and the melatonergic pathway in shaping the dynamic intercellular metabolic interactions of the various cells within the tumour microenvironment. The potentiation of YY1 and GSK3β by O-GlcNAcylation will drive changes in metabolism in tumours and tumour microenvironment cells in association with their regulation of the melatonergic pathway. The emphasis on metabolic interactions across cell types in the tumour microenvironment provides novel future research and treatment directions.

COVID-19 and COPD: a narrative review of the basic science and clinical outcomes

The 2019 coronavirus disease (COVID-19) pandemic is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Clinical outcomes, including mortality, are worse in males, older individuals and patients with comorbidities. COPD patients are included in shielding strategies due to their susceptibility to virus-induced exacerbations, compromised pulmonary function and high prevalence of associated comorbidities. Using evidence from basic science and cohort studies, this review addresses key questions concerning COVID-19 and COPD. First, are there mechanisms by which COPD patients are more susceptible to SARS-CoV-2 infection? Secondly, do inhaled corticosteroids offer protection against COVID-19? And, thirdly, what is the evidence regarding clinical outcomes from COVID-19 in COPD patients? This up-to-date review tackles some of the key issues which have significant impact on the long-term outlook for COPD patients in the context of COVID-19.

This up-to-date review tackles some of the key issues which have significant impact on the long-term outlook for COPD patients in the context of COVID-19https://bit.ly/36PKzEO

Tivozanib mediated inhibition of c-Kit/SCF signaling on Tregs and MDSCs and reversal of tumor induced immune suppression correlates with survival of HCC patients

The immune modulatory effect of tivozanib, a tyrosine kinase inhibitor, and the underlying immune mechanisms impacting survival of HCC patients have not been investigated. Pre-clinical studies have shown that tivozanib reduces Tregs and MDSCs accumulation through inhibition of c-Kit/SCF axis. We rationalized that c-Kit/SCF axis antagonism by tivozanib may reverse tumor-induced immune suppression in HCC patients. The frequency of circulating Tregs, MDSCs, CTLA-4⁺Tregs, PD-1⁺T cells, c-Kit⁺pERK-2⁺Tregs, and c-Kit⁺pERK-2⁺MDSCs were quantified in HCC patients at baseline and two time points during tivozanib treatment. We report for the first time that reduction in Tregs after tivozanib treatment and increased levels of baseline CD4⁺PD-1⁺T cells correlated with significant improvement in overall survival (OS) of the patients and these signatures may be potential biomarkers of prognostic significance. This immune modulation resulted from tivozanib-mediated blockade of c-Kit/SCF signaling, impacting ERK2 phosphorylation on Tregs and MDSCs. Low pre-treatment CD4⁺T cells: Treg ratio and reduction in the frequencies of Foxp3⁺c-Kit⁺pERK⁺Tregs after tivozanib treatment correlated significantly with progression free survival. In a comparative analysis of tivozanib vs sorafenib treatment in HCC patients, we demonstrate that decrease in the baseline numbers or frequencies of Foxp3⁺Tregs, MDSCs and exhausted T cells was significantly greater following tivozanib treatment. Additionally, greater increase in CD4⁺T cell: Treg ratio after tivozanib treatment was associated with significant improvement in OS compared to sorafenib treatment, highlighting the greater efficacy of tivozanib. These insights may help identify patients who likely would benefit from c-Kit/SCF antagonism and inform efforts to improve the efficacy of tivozanib in combination with immunotherapy.

Mycoplasmas-Host Interaction: Mechanisms of Inflammation and Association with Cellular Transformation

Mycoplasmas are the smallest and simplest self-replicating prokaryotes. Located everywhere in nature, they are widespread as parasites of humans, mammals, reptiles, fish, arthropods, and plants. They usually exhibiting organ and tissue specificity. Mycoplasmas belong to the class named Mollicutes (mollis = soft and cutis = skin, in Latin), and their small size and absence of a cell wall contribute to distinguish them from other bacteria. Mycoplasma species are found both outside the cells as membrane surface parasites and inside the cells, where they become intracellular residents as "silent parasites". In humans, some Mycoplasma species are found as commensal inhabitants, while others have a significant impact on the cellular metabolism and physiology. Mollicutes lack typical bacterial PAMPs (e.g., lipoteichoic acid, flagellin, and some lipopolysaccharides) and consequently the exact molecular mechanisms of Mycoplasmas' recognition by the cells of the immune system is the subjects of several researches for its pathogenic implications. It is well known that several strains of Mycoplasma suppress the transcriptional activity of p53, resulting in reduced apoptosis of damaged cells. In addition, some Mycoplasmas were reported to have oncogenic potential since they demonstrated not just accumulation of abnormalities but also phenotypic changes of the cells. Aim of this review is to provide an update of the current literature that implicates Mycoplasmas in triggering inflammation and altering critical cellular pathways, thus providing a better insight into potential mechanisms of cellular transformation.

"High Treg" Inflammations Promote (Most) Non-Hematologic Cancers While "Low Treg" Inflammations Promote Lymphoid Cancers

In an earlier publication, a binary classification of chronic diseases has been proposed. Chronic diseases were classified as “high Treg” or “low Treg” diseases depending on whether the pro-inflammatory or the anti-inflammatory arms of the immune response are deficient. The present work uses this model to analyze the interplay between cancer and the immune system, based on published literature. The work leans upon the etiology of alcohol and tobacco-related malignancies. The main conclusions are: triggers of specific “high Treg” immune reaction promote most non-hematologic cancers, whereas triggers of “low Treg” immune reaction promote lymphomas. The opposite is also true: triggers of specific “high Treg” immune reaction suppress lymphoma, whereas triggers of “low Treg” immune reaction suppress non-hematologic cancers. Both lymphoma and autoimmune diseases are “low Treg” conditions. For this reason, both are promoted by the same panel of “low Treg” bacteria and parasites and are inhibited by “high Treg” triggers. For example, alcohol consumption, a “high Treg” trigger, protects against lymphoma and autoimmune hypothyroidism. In addition, the same immune-modulatory drugs are effective in the treatment of both lymphoma and autoimmune diseases. Like other cancers, lymphoma transforms from a “low Treg” type at early stage of the disease into a “high Treg” type at advanced stages. However, lymphoma is distinguished from most other cancers by the length of time it dwells at an indolent “low Treg” state (many years) before lymphoma cells sensitivity to transforming growth factor-beta is impaired. This impairment stimulates the switch from “low Treg” into “high Treg” response and results in immune escape. The application of this analysis to the pharmacological activity of checkpoint inhibitors forecasts that checkpoint inhibitors would not be effective in low-grade, indolent lymphomas. As of now, checkpoint inhibitors are approved for the treatment of advanced lymphoma only.

Host responses to mucosal biofilms in the lung and gut

The impact of the human microbiome on health and disease is of utmost importance and has been studied intensively in recent years. Microbes promote immune system development and are essential to the production and absorption of nutrients for the host but are also implicated in disease pathogenesis. Particularly, bacterial biofilms have long been recognized as contributors to chronic infections and diseases in humans. However, our understanding of how the host responds to the presence of biofilms, specifically the immune response to biofilms, and how this contributes to disease pathogenesis is limited. This review aims to highlight what is known about biofilm formation and in vivo models available for the biofilm study. We critique the contribution of biofilms to human diseases, focusing on the lung diseases, cystic fibrosis and chronic obstructive pulmonary disease, and the gut diseases, inflammatory bowel disease and colorectal cancer.

Role of Regulatory T Cells in Disturbed Immune Homeostasis in Patients With Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a complex chronic disease in which T cell-mediated pulmonary inflammation has been shown to play a key role. Accumulating evidence shows that COPD has many of the characteristics of an autoimmune response. An adaptive immune response directed against lung self-antigens, which are released during the initial innate inflammatory response and are triggered by constant exposure to cigarette smoke and epithelial injury, drives the persistent inflammatory response found in smokers. The development and severity of adaptive inflammation depend on the level of tolerance to self-antigens. For these reasons, the effect of regulatory T (Treg) cells on adaptive immunity in COPD patients is of particular interest and could be targeted therapeutically. The disturbance in immune homeostasis caused by changes in the number or function of Treg cells, which is related to cigarette smoke exposure, may be of importance in understanding the development and progression of COPD.

Identification of dynamic signatures associated with smoking-related squamous cell lung cancer and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a risk factor for the development of lung cancer. The aim of this study was to identify early diagnosis biomarkers for lung squamous cell carcinoma (SQCC) in COPD patients and to determine the potential pathogenetic mechanisms. The GSE12472 data set was downloaded from the Gene Expression Omnibus database. Differentially co‐expressed links (DLs) and differentially expressed genes (DEGs) in both COPD and normal tissues, or in both SQCC + COPD and COPD samples were used to construct a dynamic network associated with high‐risk genes for the SQCC pathogenetic process. Enrichment analysis was performed based on Gene Ontology annotations and Kyoto Encyclopedia of Genes and Genomes pathway analysis. We used the gene expression data and the clinical information to identify the co‐expression modules based on weighted gene co‐expression network analysis (WGCNA). In total, 205 dynamic DEGs, 5034 DLs and one pathway including CDKN1A, TP53, RB1 and MYC were found to have correlations with the pathogenetic progress. The pathogenetic mechanisms shared by both SQCC and COPD are closely related to oxidative stress, the immune response and infection. WGCNA identified 11 co‐expression modules, where magenta and black were correlated with the “time to distant metastasis.” And the “surgery due to” was closely related to the brown and blue modules. In conclusion, a pathway that includes TP53, CDKN1A, RB1 and MYC may play a vital role in driving COPD towards SQCC. Inflammatory processes and the immune response participate in COPD‐related carcinogenesis.

Regulatory T Cells in Respiratory Health and Diseases

Respiratory diseases compromise the health of millions of people all over the world and are strongly linked to the immune dysfunction. CD4+FOXP3+ T regulatory cells, also known as Tregs, have a central role maintaining tissue homeostasis during immune responses. Their activity and clinical impact have been widely studied in different clinical conditions including autoimmune diseases, inflammatory conditions, and cancer, amongst others. Tregs express transcription factor forkhead box P3 (FOXP3), which allows regulation of the immune response through anti-inflammatory cytokines such as IL-10 or transforming growth factor beta (TGF-β) and direct cell-to-cell interaction. Maintenance of immune tolerance is achieved via modulation of effector CD4+ T helper 1, 2 or 17 (Th1, Th2, Th17) cells by Tregs. This review highlights the recent progress in the understanding of Tregs in different disorders of the respiratory system.

Chronic obstructive pulmonary disease (COPD) and lung cancer: common pathways for pathogenesis

Chronic obstructive pulmonary disease (COPD) and lung cancer comprise the leading causes of lung disease-related mortality worldwide. Exposure to tobacco smoke is a mutual aetiology underlying the two diseases, accounting for almost 90% of cases. There is accumulating evidence supporting the role of immune dysfunction, the lung microbiome, extracellular vesicles and underlying genetic susceptibility in the development of COPD and lung cancer. Further, epigenetic factors, involving DNA methylation and microRNA expression, have been implicated in both diseases. Chronic inflammation is a key feature of COPD and could be a potential driver of lung cancer development. Using next generation technologies, further studies investigating the genomics, epigenetics and gene-environment interaction in key molecular pathways will continue to elucidate the pathogenic mechanisms underlying the development of COPD and lung cancer, and contribute to the development of novel diagnostic and prognostic tools for early intervention and personalised therapeutic strategies.

Effect of PD-1 inhibitor on exhaled nitric oxide and pulmonary function in non-small cell lung cancer patients with and without COPD

Background

Nivolumab, a programmed death 1 (PD-1) immune checkpoint inhibitor, has been shown to improve survival in non-small cell lung cancer (NSCLC). The possible involvement of PD-1 axis in the pathogenesis of inflammatory lung disease, such as chronic obstructive pulmonary disease (COPD) has also been reported. However, effects of PD-1 blockade on the respiratory system remain unknown.

Objectives

This prospective study aimed to investigate whether inhibition of the PD-1 axis altered lung inflammation and pulmonary function in NSCLC patients with and without COPD.

Method

This was a prospective multi-center study. Measurements of fractioned exhaled nitric oxide (FeNO) and pulmonary function were performed before and after 4 cycles of nivolumab therapy.

Results

A total of 137 patients with NSCLC were initially enrolled, and subsequently 95 patients (41 COPD and 54 non-COPD) receiving 4 cycles of nivolumab administration were included. After anti-PD-1 therapy, FeNO levels were significantly elevated together with increase in peripheral eosinophils. Interestingly, significant FeNO elevation was only found in COPD patients without increased peripheral eosinophils, but this was not the case in non-COPD patients. Additionally, COPD patients exhibited significant increases in FVC and FEV₁ but no changes in dyspnea scales, and acute exacerbation did not occur during the therapy.

Conclusion

Our observations suggest that anti-PD-1 therapy changed FeNO levels and pulmonary function in NSCLC patients. This therapy does not worsen COPD in terms of symptoms, pulmonary function, or acute exacerbation.

Augmentation of IFN-γ+ CD8+ T cell responses correlates with survival of HCC patients on sorafenib therapy

BACKGROUNDSorafenib has been shown to reduce the extent of immunosuppression in patients with hepatocellular carcinoma (HCC). The rationale of this investigation was to identify biomarkers that can predict treatment efficacy of sorafenib in HCC patients and to unravel the mechanism by which sorafenib impedes immune suppression mediated by distinct immunosuppressive cell subsets.METHODSWith informed consent, blood samples were collected from 30 patients with advanced HCC, at baseline and 2 time points after initiation of sorafenib treatment. The frequency of PD-1+ T cells, ERK2 phosphorylation on flt-3+ Tregs and MDSCs, and T effector cell function were quantified by using flow cytometry.RESULTSElevated levels of CD8+Ki67+ T cells producing IFN-γ were associated with improved progression-free survival and overall survival (OS). High frequencies of these T cells were correlated with significantly reduced risk of death over time. Patients with an increased pretreatment T effector/Treg ratio showed significant improvement in OS. ERK+flt-3+ Tregs and MDSCs were significantly decreased after sorafenib therapy. Increased numbers of baseline flt-3+p-ERK+ MDSCs were associated with survival benefit of patients.CONCLUSIONA high baseline CD4+ T effector/Treg ratio is a potential biomarker of prognostic significance in HCC. CD8+Ki67+ T cells producing IFN-γ are a key biomarker of response to sorafenib therapy resulting in survival benefit. The immune modulation resulted from sorafenib-mediated blockade of signaling through the VEGF/VEGFR/flt-3 pathway, affecting ERK phosphorylation. These insights may help identify patients who likely would benefit from VEGFR antagonism and inform efforts to improve the efficacy of sorafenib in combination with immunotherapy.TRIAL REGISTRATIONNCT02072486.FUNDINGNational Comprehensive Cancer Network Oncology Research Program from general research support provided by Bayer US LLC (NCCNSORA0002), National Cancer Institute grant P30CA016056, and pilot funds from Roswell Park Alliance Foundation.

Peripheral blood CD4+ T cell populations by CD25 and Foxp3 expression as a potential biomarker: reflecting inflammatory activity in chronic obstructive pulmonary disease

Background

The temporally dynamic changes of CD25 and Foxp3 expression in CD4+ T cells are initiated by T cell receptor (TCR) signals strength or frequency. There is a deficiency of peripheral markers for assessing COPD activity, and the current study was conducted to explore whether peripheral CD4+ T cell populations based on CD25 and Foxp3 expression could serve as an indicator for COPD inflammatory activity.

Methods

The distribution and phenotypic characteristics of CD4+CD25±Foxp3± T cells from peripheral blood in different populations were determined by flow cytometry. The model for the differentiation of CD4+ T cells populations by CD25 and Foxp3 expression was explored in vitro.

Results

The frequencies of peripheral CD4+CD25+Foxp3- T cells and CD4+CD25+Foxp3+ T cells were increased in AECOPD patients, whereas the frequency of CD4+CD25-Foxp3+ T cells was increased in SCOPD patients without receiving systemic treatment. Phenotypic analysis revealed that CD4+CD25+Foxp3- T cells, CD4+CD25+Foxp3+ T cells and CD4+CD25-Foxp3+ T cells had received antigenic stimulation and resembled central memory or effector memory T cells. The differentiation of CD4+ T cells populations by CD25 and Foxp3 expression was dictated by TCR signals. The paired study indicated that the frequencies of CD4+CD25+Foxp3- T cells, CD4+CD25+Foxp3+ T cells and CD4+CD25- Foxp3+ T cells were decreased while the frequency of CD4+CD25-Foxp3- T cells were increased in the same patients from AECOPD to convalescence.

Conclusions

Collectively, we propose that the dynamic changes of CD4+ T cell populations by CD25 and Foxp3 expression could function as potential biomarkers for reflecting inflammatory activity in COPD.

The Modulation of Regulatory T Cells via HMGB1/PTEN/β-Catenin Axis in LPS Induced Acute Lung Injury

Sepsis-induced acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) remains the leading complication for mortality caused by bacterial infection. The regulatory T (Treg) cells appear to be an important modulator in resolving lung injury. Despite the extensive studies, little is known about the role of macrophage HMGB1/PTEN/β-catenin signaling in Treg development during ALI.

Objectives: This study was designed to determine the roles and molecular mechanisms of HMGB1/PTEN/β-catenin signaling in mediating CD4⁺CD25⁺Foxp3⁺ Treg development in sepsis-induced lung injury in mice.

Setting: University laboratory research of First Affiliated Hospital of Anhui Medical University.

Subjects: PTEN/β-catenin Loxp and myeloid-specific knockout mice.

Interventions: Groups of PTEN^loxp/β-catenin^loxp and myeloid-specific PTEN/β-catenin knockout (PTEN^M−KO/β-catenin^M−KO) mice were treated with LPS or recombinant HMGB1 (rHMGB1) to induce ALI. The effects of HMGB1-PTEN axis were further analyzed by in vitro co-cultures.

Measures and Main Results: In a mouse model of ALI, blocking HMGB1 or myeloid-specific PTEN knockout (PTEN^M−KO) increased animal survival/body weight, reduced lung damage, increased TGF-β production, inhibited the expression of RORγt and IL-17, while promoting β-catenin signaling and increasing CD4⁺CD25⁺Foxp3⁺ Tregs in LPS- or rHMGB-induced lung injury. Notably, myeloid-specific β-catenin ablation (β-catenin^M−KO) resulted in reduced animal survival and increased lung injury, accompanied by reduced CD4⁺CD25⁺Foxp3⁺ Tregs in rHMGB-induced ALI. Furthermore, disruption of macrophage HMGB1/PTEN or activation of β-catenin significantly increased CD4⁺CD25⁺Foxp3⁺ Tregs in vitro.

Conclusions: HMGB1/PTEN/β-catenin signaling is a novel pathway that regulates Treg development and provides a potential therapeutic target in sepsis-induced lung injury.

An immunometabolic pathomechanism for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is an inflammatory disease characterized by limitation of expiratory airflow. Cellular and molecular pathways involved in disease pathogenesis are not completely defined. Our study reveals that metabolism and immune response cooperate in COPD pathogenesis and progression. COPD subjects with different disease stages showed progressive increase of systemic leptin, an adipose tissue-derived proinflammatory molecule, that, at high concentrations, impaired the capacity of T cells to engage in glycolysis and to generate regulatory T cells. Thus, the loss of these immunoregulatory circuits during COPD determined the hyperactivation of effector T cells that amplified inflammation, leading to progressive decline of lung function. Understanding these immunometabolic mechanisms can have important implications for monitoring COPD progression and for disease treatment.

Chronic obstructive pulmonary disease (COPD) is an inflammatory condition associated with abnormal immune responses, leading to airflow obstruction. Lungs of COPD subjects show accumulation of proinflammatory T helper (Th) 1 and Th17 cells resembling that of autoreactive immune responses. As regulatory T (T_reg) cells play a central role in the control of autoimmune responses and their generation and function are controlled by the adipocytokine leptin, we herein investigated the association among systemic leptin overproduction, reduced engagement of glycolysis in T cells, and reduced peripheral frequency of T_reg cells in different COPD stages. These phenomena were also associated with an impaired capacity to generate inducible T_reg (iT_reg) cells from conventional T (T_conv) cells. At the molecular level, we found that leptin inhibited the expression of forkhead-boxP3 (FoxP3) and its splicing variants containing the exon 2 (FoxP3-E2) that correlated inversely with inflammation and weakened lung function during COPD progression. Our data reveal that the immunometabolic pathomechanism leading to COPD progression is characterized by leptin overproduction, a decline in the expression of FoxP3 splicing forms, and an impairment in T_reg cell generation and function. These results have potential implications for better understanding the autoimmune-like nature of COPD and the pathogenic events leading to lung damage.

ILC2s Induce Adaptive Th2-Type Immunity in Acute Exacerbation of Chronic Obstructive Pulmonary Disease

To investigate the effect of ILC2s on Th2-type adaptive immunity during the acute exacerbation of chronic obstructive pulmonary disease (AECOPD), the study enrolled healthy people, stable COPD patients, and AECOPD patients. Flow cytometry was used to detect Th1, Th2, and ILC2 in the peripheral blood and CD80 and MHC II levels on ILC2. The mRNA levels of GATA3, RORα, and CRTH2 of ILC2s were detected by RT-PCR. In addition, ILC2s from the peripheral blood of AECOPD patients were cocultured with CD4⁺ T cells from the peripheral blood of healthy controls. Cytokine levels in serum of the three groups and the in vitro coculture supernatants were measured by ELISA. Compared with the stable COPD group or the healthy control group, Th2 in the peripheral blood of AECOPD group increased dramatically, inducing an increase of Th2/Th1 ratio in AECOPD patients. Meanwhile, the level of IL-4 in the serum of this group was also increased. However, we also detected ILC2s in the peripheral blood of the AECOPD group and found that it was also increased, alone with the increased GATA3, RORα, and CRTH2 mRNA levels. We also found that the CD80 and MHC II on ILC2 were significantly upregulated and the proportion of MHC II⁺ ILC2 cells was significantly positively correlated with the proportion of Th2 cells in AECOPD patients. To further demonstrate the effect of ILC2 on Th2 cells, we cocultured ILC2 with CD4⁺ T cells in vitro, which also showed a significant increase of Th2 ratio as well as Th2-associated cytokines IL-4, IL-5, and IL-13. However, we found that this effect of ILC2s on Th2 cells could be inhibited by the addition of anti-MHC II. The Th2/Th1 balance shifts to Th2 in AECOPD. ILC2s may function as APC by the upregulation of MHC II and regulate adaptive immunity shift to Th2-type response in AECOPD.

The Clinical Significance of Programmed Death-1, Regulatory T Cells and Myeloid Derived Suppressor Cells in Patients with Nontuberculous Mycobacteria-Lung Disease

Background: Increasing expression of programmed death-1 (PD-1) in patients with nontuberculous mycobacteria lung disease (NTM-LD) has been reported, but its role in clinical characteristics and outcomes remains unclear. Methods: We enrolled 96 participants, including 46 with Mycobacterium avium complex (MAC)-LD, 23 with M. abscessus (MAB)-LD, and 27 controls. We measured expressions of PD-1, cytotoxic T-lymphocyte antigen-4 (CTLA-4) and regulatory T (Treg) cells on CD4⁺ lymphocytes and myeloid-derived suppressor cells (MDSCs) and analyzed their association with clinical features and radiographic outcomes. Results: The percentage of PD-1 on CD4⁺(PD-1⁺CD4⁺) lymphocytes and MDSCs were higher in the MAC-LD group than the controls. There were no intergroup differences regarding CTLA-4⁺CD4⁺ lymphocytes. Higher PD-1⁺CD4⁺ lymphocytes were found in M. intracellulare- and M. avium-LD than in other MAC-LD. Positive sputum acid-fast stains and fibrocavitary radiographic lesions were correlated with elevated PD-1⁺CD4⁺ lymphocytes and Treg cells. The percentage of PD-1⁺CD4⁺ lymphocytes at the initial and 2 months of follow-up significantly predicted subsequent radiographic progression. Conclusion: As markers of immune tolerance, PD-1⁺CD4⁺ lymphocytes and MDSCs were higher in MAC-LD patients. The levels of PD-1⁺CD4⁺ and Treg cells were correlated with high mycobacteria bacilli burden in NTM-LD. Monitoring the expressions of PD-1⁺CD4⁺ lymphocytes may predict radiographic progression.

Effect of COPD on Inflammation, Lymphoid Functions and Progression-Free Survival during First-Line Chemotherapy in Advanced Non-small Cell Lung Cancer

Chronic obstructive pulmonary disease (COPD) is a common comorbidity of non-small cell lung cancer (NSCLC). COPD is characterized by systemic inflammation and lymphocyte dysfunction, mechanisms that are also known to accelerate progression of advanced (IIIB-IV) stage NSCLC. We aimed to find out whether COPD exerts an influence on tumor induced inflammatory and lymphoid responses and progression-free survival (PFS) after first-line treatment in advanced NSCLC. Patients suffering from NSCLC (n = 95), COPD (n = 54), NSCLC+COPD (n = 80) and healthy controls (n = 60) were included. PFS, neutrophil granulocyte and lymphocyte cell counts were recorded. Serum IFNγ, TNFα, VEGF concentrations were measured by using multiplex cytometric bead-based immunoassay. Prevalence of myeloid-derived suppressor cell populations (MDSC-s), and signs of T cell exhaustion were tested by using flow cytometry. Median PFS increased in the NSCLC+COPD group compared to NSCLC patients without COPD (7.4 vs 4.9 months, p < 0.01). NSCLC+COPD patients had 1.7 times (1.2-2.4) more likely to have longer PFS compared to NSCLC patients without COPD (Cox analysis, p < 0.01). Neutrophil cell counts, CRP, IFNγ and TNFα concentrations were all reduced in NSCLC+COPD (all p < 0.05 vs NSCLC). NSCLC+COPD was also associated with reduced serum IL-10 concentration and increased granzyme-B positive CD8 cell counts compared to NSCLC without COPD. The effects of VEGF and MDSC-s on systemic inflammation appeared to be blunted by COPD in patients suffering from advanced NSCLC. Concomitant COPD moderates tumor-induced inflammation and supports some effector lymphoid functions and thereby may be an independent positive predictive factor of longer PFS after first-line therapy in advanced NSCLC.

Chronic Obstructive Pulmonary Disease Alters Immune Cell Composition and Immune Checkpoint Inhibitor Efficacy in Non-Small Cell Lung Cancer

RATIONALE

Chronic obstructive pulmonary disease (COPD) and non-small cell lung cancer (NSCLC) are interrelated diseases with substantial mortality, and the pathogenesis of both involves aberrant immune functioning.

OBJECTIVES

To profile immune cell composition and function in patients with NSCLC and describe the effects of COPD on lung and tumor microenvironments.

METHODS

We profiled resected lung and tumor tissue using flow cytometry and T-cell receptor sequencing in patients with and without COPD from a prospective cohort of patients undergoing resection of NSCLC. A murine cigarette smoke exposure model was used to evaluate the effect on pulmonary immune populations. A separate retrospective cohort of patients who received immune checkpoint inhibitors (ICIs) was analyzed, and their survival was quantified.

MEASUREMENTS AND MAIN RESULTS

We observed an increased number of IFN-γ-producing CD8⁺ and CD4⁺ (T-helper cell type 1 [Th1]) lymphocytes in the lungs of patients with COPD. In both humans and mice, increased Th17 content was seen with smoke exposure, but was not associated with the development or severity of COPD. COPD-affected lung tissue displayed increased Th1 differentiation that was recapitulated in the matching tumor sample. PD-1 (programmed cell death protein 1) expression was increased in tumors of patients with COPD, and the presence of COPD was associated with progression-free survival in patients treated with ICIs.

CONCLUSIONS

In patients with COPD, Th1 cell populations were expanded in both lung and tumor microenvironments, and the presence of COPD was associated with longer progression-free intervals in patients treated with ICIs. This has implications for understanding the immune mediators of COPD and developing novel therapies for NSCLC.

Generation and Immune Regulation of CD4+CD25-Foxp3+ T Cells in Chronic Obstructive Pulmonary Disease

The imbalance of CD4⁺Foxp3⁺ T cell subsets is reportedly involved in abnormal inflammatory immune responses in patients with chronic obstructive pulmonary disease (COPD). However, the possible role of CD4⁺CD25^-Foxp3⁺ T cells in immune regulation in COPD remains to be investigated. In the current study, distribution and phenotypic characteristics of CD4⁺CD25^-Foxp3⁺ T cells from peripheral blood were determined by flow cytometry; the origin, immune function and ultimate fate of CD4⁺CD25^-Foxp3⁺ T cells were further explored in vitro. It was observed that circulating CD4⁺CD25^-Foxp3⁺ T cells were significantly increased in stable COPD patients (SCOPD) and resembled central memory or effector memory T cells. Compared with peripheral CD4⁺CD25⁺Foxp3⁺ T cells, peripheral CD4⁺CD25^-Foxp3⁺ T cells showed a lower expression of Foxp3, CTLA-4, HELIOS, and TIGIT, but a higher expression of CD127 and KI-67, suggesting that CD4⁺CD25^-Foxp3⁺ T cells lost the expression of Tregs-associated molecules following the reduction in CD25. Unexpectedly, our study found that transforming growth factor-β1 (TGFβ1) decreased CD25 expression and played a critical role in the generation of CD4⁺CD25^-Foxp3⁺ T cells from CD4⁺CD25⁺Foxp3⁺ T cells. Phenotypic analysis further revealed that both inducible and peripheral CD4⁺CD25^-Foxp3⁺ T cells exhibited the features of activated conventional T cells. Importantly, memory CD4⁺CD25^-Foxp3⁺ T cells facilitated the proliferation and differentiation of naïve CD4⁺ T cells into Th17 cells in the presence of IL-1β, IL-6, IL-23, and TGFβ1. Finally, a fraction of CD4⁺CD25^-Foxp3⁺ T cells, exhibiting instability and plasticity, were converted to Th17 cells when subjected to Th17 cell-polarizing condition. Taken together, we propose that TGFβ1 is responsible for the generation of CD4⁺CD25^-Foxp3⁺ T cells, and these cells functionally exert an auxiliary effect on Th17 cells generation and might perpetuate chronic inflammation in COPD.

Immunodeficiency in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD), characterized by progressive airway inflammation and irreversible airflow limitation, leads to serious decline in life quality. The acute exacerbation of COPD (AECOPD) results in high healthcare costs as well as a significant mortality rate. The most common cause of acute exacerbation is infection. Immune deficiency, which induces dysfunction of anti-infection, plays an important role in the pathogenesis of acute exacerbation. As described in this review, the immune dysfunction in patients with AECOPD can be a major focus of efforts to therapeutic strategy.

What is early COPD and why is it important?

There is increasing interest in the origins of chronic obstructive pulmonary disease (COPD), as it is envisaged that preventive efforts and treatment can modify its clinical course. The concept of early COPD is not new, but it has recently regained interest, given new population data, recent cellular and molecular advances and insights from clinical trials. To date, many knowledge gaps in the nature of early COPD still exist, mainly because COPD has always been considered a disease of the elderly, and little attention has been paid to the pathological changes occurring in the lungs of individuals at risk before they develop clinically evident COPD. Future studies should focus on identifying early pathological manifestations of COPD in order to prevent its progression in susceptible individuals. In this review, we aim to summarise what is known on early COPD, from the epidemiological, cellular and clinical perspectives.