Sputum T lymphocytes in asthma, COPD and healthy subjects have the phenotype of activated intraepithelial T cells (CD69+ CD103+)

Comprehensive analysis reveals the potential value of inflammatory response genes in the prognosis, immunity, and drug sensitivity of lung adenocarcinoma

Background

Although the relationship between inflammatory response and tumor has been gradually recognized, the potential implications of of inflammatory response genes in lung adenocarcinoma (LUAD) remains poorly investigated.

Methods

RNA sequencing and clinical data were obtained from multiple independent datasets (GSE29013, GSE30219, GSE31210, GSE37745, GSE42127, GSE50081, GSE68465, GSE72094, TCGA and GTEx). Unsupervised clustering analysis was used to identify different tumor subtypes, and LASSO and Cox regression analysis were applied to construct a novel scoring tool. We employed multiple algorithms (ssGSEA, CIBERSORT, MCP counter, and ESTIMATE) to better characterize the LUAD tumor microenvironment (TME) and immune landscapes. GSVA and Metascape analysis were performed to investigate the biological processes and pathway activity. Furthermore, ‘pRRophetic’ R package was used to evaluate the half inhibitory concentration (IC50) of each sample to infer drug sensitivity.

Results

We identified three distinct tumor subtypes, which were related to different clinical outcomes, biological pathways, and immune characteristics. A scoring tool called inflammatory response gene score (IRGS) was established and well validated in multiple independent cohorts, which could well divide patients into two subgroups with significantly different prognosis. High IRGS patients, characterized by increased genomic variants and mutation burden, presented a worse prognosis, and might show a more favorable response to immunotherapy and chemotherapy. Additionally, based on the cross-talk between TNM stage, IRGS and patients clinical outcomes, we redefined the LUAD stage, which was called ‘IRGS-Stage’. The novel staging system could distinguish patients with different prognosis, with better predictive ability than the conventional TNM staging.

Conclusions

Inflammatory response genes present important potential value in the prognosis, immunity and drug sensitivity of LUAD. The proposed IRGS and IRGS-Stage may be promising biomarkers for estimating clinical outcomes in LUAD patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01340-7.

Pathogenesis, clinical features of asthma COPD overlap (ACO), and therapeutic modalities

Both asthma and COPD are heterogeneous diseases identified by characteristic symptoms and functional abnormalities, with airway obstruction common in both diseases. Asthma COPD overlap (ACO) does not define a single disease but is a descriptive term for clinical use that includes several overlapping clinical phenotypes of chronic airways disease with different underlying mechanisms. This literature review was initiated to describe published studies, identify gaps in knowledge, and propose future research goals regarding the disease pathology of ACO, especially the airway remodelling changes and inflammation aspects. Airway remodelling occurs in asthma and COPD, but there are differences in the structures affected and the prime anatomic site at which they occur. Reticular basement membrane thickening and cellular infiltration with eosinophils and T-helper (CD4+) lymphocytes are prominent features of asthma. Epithelial squamous metaplasia, airway wall fibrosis, emphysema, bronchoalveolar lavage (BAL) neutrophilia and (CD8+) T-cytotoxic lymphocyte infiltrations in the airway wall are features of COPD. There is no universally accepted definition of ACO, nor are there clearly defined pathological characteristics to differentiate from asthma and COPD. Understanding etiological concepts within the purview of inflammation and airway remodelling changes in ACO would allow better management of these patients.

Epithelial Barrier Dysfunction in Chronic Respiratory Diseases

Mucosal surfaces are lined by epithelial cells, which provide a complex and adaptive module that ensures first-line defense against external toxics, irritants, antigens, and pathogens. The underlying mechanisms of host protection encompass multiple physical, chemical, and immune pathways. In the lung, inhaled agents continually challenge the airway epithelial barrier, which is altered in chronic diseases such as chronic obstructive pulmonary disease, asthma, cystic fibrosis, or pulmonary fibrosis. In this review, we describe the epithelial barrier abnormalities that are observed in such disorders and summarize current knowledge on the mechanisms driving impaired barrier function, which could represent targets of future therapeutic approaches.

The Role of T Cells and Macrophages in Asthma Pathogenesis: A New Perspective on Mutual Crosstalk

Asthma is associated with innate and adaptive immunity mediated by immune cells. T cell or macrophage dysfunction plays a particularly significant role in asthma pathogenesis. Furthermore, crosstalk between them continuously transmits proinflammatory or anti-inflammatory signals, causing the immune cell activation or repression in the immune response. Consequently, the imbalanced immune microenvironment is the major cause of the exacerbation of asthma. Here, we discuss the role of T cells, macrophages, and their interactions in asthma pathogenesis.

Effect of acupoint application on T lymphocyte subsets in patients with chronic obstructive pulmonary disease: A meta-analysis

BACKGROUND

The development of chronic obstructive pulmonary disease (COPD) is related to the T lymphocyte mediated inflammatory immune response and immune imbalance. The purpose of this systematic review was to evaluate the clinical efficacy and safety of acupoint application on T lymphocyte subsets in patients with COPD.

METHODS

We searched CNKI, Wan fang, Chongqing VIP, China Biology Medicine disc, PubMed, the Cochrane Library, and EMBASE for studies published as of Oct. 31, 2019. All randomized controlled trials of acupoint application on COPD patients that met the inclusion criteria were included. The Cochrane bias risk assessment tool was used for literature evaluation. RevMan5.3 software was used for meta-analysis.

RESULTS

Eight studies (combined n = 524) qualified based on the inclusion criteria. Compared with routine treatment alone, acupoint application combined with routine treatment can significantly increase the T lymphocyte CD4/CD8 ratio (MD 0.12, 95% CI 0.03-0.21, P < .01, I = 49%), reduce CD8 T-cells (MD-0.99, 95% CI-1.70-0.28, P < .001, I = 37%), reduce the times of acute exacerbations (MD-0.28, 95% CI-0.35-0.21, P < .001, I = 0), and improve the clinical efficacy (MD 1.30, 95% CI 1.14-1.48, P < .001, I = 39%).

CONCLUSION

Acupoint application can improve the CD4/CD8 ratio and CD8 T-cells in patients with COPD and has an auxiliary effect in reducing the times of acute exacerbations and improving clinical efficacy.

Proinflammatory Pathways in the Pathogenesis of Asthma

There are multiple proinflammatory pathways in the pathogenesis of asthma. These include both innate and adaptive inflammation, in addition to inflammatory and physiologic responses mediated by eicosanoids. An important component of the innate allergic immune response is ILC2 activated by interleukin (IL)-33, thymic stromal lymphopoietin, and IL-25 to produce IL-5 and IL-13. In terms of the adaptive T-lymphocyte immunity, CD4+ Th2 and IL-17-producing cells are critical in the inflammatory responses in asthma. Last, eicosanoids involved in asthma pathogenesis include prostaglandin D₂ and the cysteinyl leukotrienes that promote smooth muscle constriction and inflammation that propagate allergic responses.

CD8+ Tc2 cells: underappreciated contributors to severe asthma

The complexity of asthma is underscored by the number of cell types and mediators implicated in the pathogenesis of this heterogeneous syndrome. Type 2 CD4⁺ T-cells (Th2) and more recently, type 2 innate lymphoid cells dominate current descriptions of asthma pathogenesis. However, another important source of these type 2 cytokines, especially interleukin (IL)-5 and IL-13, are CD8⁺ T-cells, which are increasingly proposed to play an important role in asthma pathogenesis, because they are abundant and are comparatively insensitive to corticosteroids. Many common triggers of asthma exacerbations are mediated via corticosteroid-resistant pathways involving neutrophils and CD8⁺ T-cells. Extensive murine data reveal the plasticity of CD8⁺ T-cells and their capacity to enhance airway inflammation and airway dysfunction. In humans, Tc2 cells are predominant in fatal asthma, while in stable state, severe eosinophilic asthma is associated with greater numbers of Tc2 than Th2 cells in blood, bronchoalveolar lavage fluid and bronchial biopsies. Tc2 cells strongly express CRTH2, the receptor for prostaglandin D2, the cysteinyl leukotriene receptor 1 and the leukotriene B4 receptor. When activated, these elicit Tc2 cell chemotaxis and production of chemokines and type 2 and other cytokines, resulting directly or indirectly in eosinophil recruitment and survival. These factors position CD8⁺ Tc2 cells as important and underappreciated effector cells contributing to asthma pathogenesis. Here, we review recent advances and new insights in understanding the pro-asthmatic functions of CD8⁺ T-cells in eosinophilic asthma, especially corticosteroid-resistant asthma, and the molecular mechanisms underlying their pathologic effector function.

Alongside Th2 and ILC2 cells, CD8⁺ T-cells are a cellular source of type 2 cytokines. We review recent findings and insights into the pathologic effector functions of type 2 CD8⁺ T-cells in eosinophilic asthma, especially steroid-resistant disease.http://bit.ly/2KbVGL2

Sputum from chronic obstructive pulmonary disease patients inhibits T cell migration in a microfluidic device

Chronic obstructive pulmonary disease (COPD) is a common lung disease characterized by narrowed airways, resulting in serious breathing difficulty. Previous studies have demonstrated that inflammatory infiltration of leukocytes in the airway is associated with the pathogenesis of COPD. In the present study, we employed a microfluidic approach to assess the effect of COPD sputum on activated human peripheral blood T cell migration and chemotaxis under well-controlled gradient conditions. Our results showed considerable basal migration of T cells derived from peripheral blood of COPD patients and healthy controls in the medium control groups. By contrast, the migration of T cells from COPD patients and healthy controls was significantly inhibited in the presence of a gradient of sputum supernatant from COPD patients. Furthermore, chemotaxis of T cells from COPD patients or healthy subjects toward an SDF-1α gradient was clearly inhibited by sputum samples from the COPD patients. The inhibition effect revealed by the microfluidic cell migration experiments provides new information about the complex involvement of T cell trafficking in COPD.

T-cell profile and systemic cytokine levels in overweight-obese patients with moderate to very-severe COPD

This study aimed to evaluate the immune profile of lean and overweight-obese COPD patients. Forty patients with moderate to very severe COPD were divided into lean group (n=20; aged 62.00±8.91years; BMI 22.26±1.65kg/m²) or overweight-obese group (n=20; aged 65.40±6.69years; BMI 29.19±3.55kg/m²). The cytokine profile (IL-2, IL-4, IL-6, IL-10, INF-γ, and TNF-α) was evaluated through the Cytometric Bead Array technique, and the expression of CD4, CD8, CD25, CD45ra, CD45ro, CD69, CD195(CCr5) and HLA-DR were evaluated in CD3+ T-cells. Overweight-obese COPD group had lower levels of IL-2 (p=0.01) and higher INF-γ levels (p=0.02) and IL-6 (p=0.003) than lean COPD. Lean COPD patients had higher CD25+ (p=0.01), CCr5 (p=0.04) and HLA-DR (p=0.007) expression on T cell surface compared to overweight-obese COPD participants. These changes are related to immune dysfunction of obesity, and excess of fat mass in COPD can be a key factor to low T-cells activation.

Airway inflammation in chronic obstructive pulmonary disease (COPD): a true paradox

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is primarily an airway condition, which mainly affects cigarette smokers and presents with shortness of breath that is progressive and poorly reversible. In COPD research, there has been a long held belief that airway disease progression is due to inflammation. Although this may be true in the airway lumen with innate immunity activated by the effect of smoke or secondary to infection, the accurate picture of inflammatory cells in the airway wall, where the pathophysiological COPD remodeling occurs, is uncertain and debatable. Areas covered: The current review provides a comprehensive literature survey of the changes in the main inflammatory cells in human COPD patients and focuses on contrarian views that affect the prevailing dogma on inflammation. The review also delves into the role of oxidative stress and inflammasomes in modulating the immune response in COPD. Further, the effects of inflammation in affecting the epithelium, fibroblasts, and airway remodeling are discussed. Expert commentary: Inflammation as a driving force for airway wall damage and remodelling in early COPD is at the very least 'oversimplified' and is likely to be misleading. This has serious implications for rational thinking about the illness, including pathogenesis and designing therapy.

Integrins as Therapeutic Targets for Respiratory Diseases

Integrins are a large family of transmembrane heterodimeric proteins that constitute the main receptors for extracellular matrix components. Integrins were initially thought to be primarily involved in the maintenance of cell adhesion and tissue integrity. However, it is now appreciated that integrins play important roles in many other biological processes such as cell survival, proliferation, differentiation, migration, cell shape and polarity. Lung cells express numerous combinations and permutations of integrin heterodimers. The complexity and diversity of different integrin heterodimers being implicated in different lung diseases present a major challenge for drug development. Here we provide a comprehensive overview of the current knowledge of integrins from studies in cell culture to integrin knockout mouse models and provide an update of results from clinical trials for which integrins are therapeutic targets with a focus on respiratory diseases (asthma, emphysema, pneumonia, lung cancer, pulmonary fibrosis and sarcoidosis).

Current and future biomarkers in allergic asthma

Diagnosis early in life, sensitization, asthma endotypes, monitoring of disease and treatment progression are key motivations for the exploration of biomarkers for allergic rhinitis and allergic asthma. The number of genes related to allergic rhinitis and allergic asthma increases steadily; however, prognostic genes have not yet entered clinical application. We hypothesize that the combination of multiple genes may generate biomarkers with prognostic potential. The current review attempts to group more than 161 different potential biomarkers involved in respiratory inflammation to pave the way for future classifiers. The potential biomarkers are categorized into either epithelial or infiltrate-derived or mixed origin, epithelial biomarkers. Furthermore, surface markers were grouped into cell-type-specific categories. The current literature provides multiple biomarkers for potential asthma endotypes that are related to T-cell phenotypes such as Th1, Th2, Th9, Th17, Th22 and Tregs and their lead cytokines. Eosinophilic and neutrophilic asthma endotypes are also classified by epithelium-derived CCL-26 and osteopontin, respectively. There are currently about 20 epithelium-derived biomarkers exclusively derived from epithelium, which are likely to innovate biomarker panels as they are easy to sample. This article systematically reviews and categorizes genes and collects current evidence that may promote these biomarkers to become part of allergic rhinitis or allergic asthma classifiers with high prognostic value.

Design of a multi-center immunophenotyping analysis of peripheral blood, sputum and bronchoalveolar lavage fluid in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS)

BACKGROUND

Subpopulations and Intermediate Outcomes in COPD Study (SPIROMICS) is a multi-center longitudinal, observational study to identify novel phenotypes and biomarkers of chronic obstructive pulmonary disease (COPD). In a subset of 300 subjects enrolled at six clinical centers, we are performing flow cytometric analyses of leukocytes from induced sputum, bronchoalveolar lavage (BAL) and peripheral blood. To minimize several sources of variability, we use a "just-in-time" design that permits immediate staining without pre-fixation of samples, followed by centralized analysis on a single instrument.

METHODS

The Immunophenotyping Core prepares 12-color antibody panels, which are shipped to the six Clinical Centers shortly before study visits. Sputum induction occurs at least two weeks before a bronchoscopy visit, at which time peripheral blood and bronchoalveolar lavage are collected. Immunostaining is performed at each clinical site on the day that the samples are collected. Samples are fixed and express shipped to the Immunophenotyping Core for data acquisition on a single modified LSR II flow cytometer. Results are analyzed using FACS Diva and FloJo software and cross-checked by Core scientists who are blinded to subject data.

RESULTS

Thus far, a total of 152 sputum samples and 117 samples of blood and BAL have been returned to the Immunophenotyping Core. Initial quality checks indicate useable data from 126 sputum samples (83%), 106 blood samples (91%) and 91 BAL samples (78%). In all three sample types, we are able to identify and characterize the activation state or subset of multiple leukocyte cell populations (including CD4+ and CD8+ T cells, B cells, monocytes, macrophages, neutrophils and eosinophils), thereby demonstrating the validity of the antibody panel.

CONCLUSIONS

Our study design, which relies on bi-directional communication between clinical centers and the Core according to a pre-specified protocol, appears to reduce several sources of variability often seen in flow cytometric studies involving multiple clinical sites. Because leukocytes contribute to lung pathology in COPD, these analyses will help achieve SPIROMICS aims of identifying subgroups of patients with specific COPD phenotypes. Future analyses will correlate cell-surface markers on a given cell type with smoking history, spirometry, airway measurements, and other parameters.

TRIAL REGISTRATION

This study was registered with ClinicalTrials.gov as NCT01969344 .

Genomics of Chronic Obstructive Pulmonary Disease (COPD); Exploring the SNPs of Protease-Antiprotease Pathway

The COPD has been an important respiratory condition that affects people worldwide and its incidence has been alarming. The increasing incidence of this disorder has been attributed to global industrialization and environmental pollution. Although the exposures to environmental pollutants and smoking have been important triggers, the genetic component of individuals has been shown to be important for development and progression of COPD. Recent literature reported that protease-antiprotease imbalance to be important in etiopathogenesis of COPD. The enzymes namely neutrophil elastase and matrix metalloprotienases are considered to be foremost proteolytic molecules released by neutrophils and macrophages during inflammatory events in COPD. Normally, the lungs remain protected from the destructive effect of these two antiproteases by α1-antitrypsin (α1AT) and tissue inhibitors of metalloproteinases (TIMPs) respectively. In this review, we are trying to highlight the work by various research groups in exploring the SNPs of various genes of inflammatory pathways and the protease-antiprotease pathway, which may have some degree of association with COPD.

Differential activation of killer cells in the circulation and the lung: a study of current smoking status and chronic obstructive pulmonary disease (COPD)

BACKGROUND

CD8(+) T-lymphocytes, natural killer T-like cells (NKT-like cells, CD56(+)CD3(+)) and natural killer cells (NK cells, CD56(+)CD3(-)) are the three main classes of human killer cells and they are implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). Activation of these cells can initiate immune responses by virtue of their production of inflammatory cytokines and chemokines that cause lung tissue damage, mucus hypersecretion and emphysema. The objective of the current study was to investigate the activation levels of human killer cells in healthy non-smokers, healthy smokers, ex-smokers with COPD and current smokers with COPD, in both peripheral blood and induced sputum.

METHODS/PRINCIPAL FINDINGS

After informed consent, 124 participants were recruited into the study and peripheral blood or induced sputum was taken. The activation states and receptor expression of killer cells were measured by flow cytometry. In peripheral blood, current smokers, regardless of disease state, have the highest proportion of activated CD8(+) T-lymphocytes, NKT-like cells and NK cells compared with ex-smokers with COPD and healthy non-smokers. Furthermore, CD8(+) T-lymphocyte and NK cell activation is positively correlated with the number of cigarettes currently smoked. Conversely, in induced sputum, the proportion of activated killer cells was related to disease state rather than current smoking status, with current and ex-smokers with COPD having significantly higher rates of activation than healthy smokers and healthy non-smokers.

CONCLUSIONS

A differential effect in systemic and lung activation of killer cells in COPD is evident. Systemic activation appears to be related to current smoking whereas lung activation is related to the presence or absence of COPD, irrespective of current smoking status. These findings suggest that modulating killer cell activation may be a new target for the treatment of COPD.

Statins enhance the effects of corticosteroids on the balance between regulatory T cells and Th17 cells

BACKGROUND

Plasticity of CD4(+) lymphocyte Th17/regulatory T cell (Treg) subsets is involved in the pathogenesis of chronic airway inflammatory diseases, such as asthma. Reversal of Th17/Treg cell balance towards Treg cells may be beneficial for the suppression of chronic Th2 cell-mediated inflammatory diseases, such as asthma. However, the effect of the combination of corticosteroids and a statin on the ratio of Treg/Th17 cells is unknown.

OBJECTIVE

We investigated the in vitro effects of the combination of simvastatin and fluticasone propionate (FP) on the numbers of Treg and Th17 cells in asthmatic patients after co-incubation with monocyte-derived DCs (mDCs), and explored the underlying signalling pathways involved.

METHODS

Using flow cytometry, we determined the effects of FP and simvastatin on Treg/Th17 balance after co-incubation of asthmatic CD4(+) T cells with mDCs. We also measured the relevant Treg and Th17-polarizing cytokines released from mDCs and also investigated the role of indoleamine 2, 3-dioxygenase (IDO) in this response.

RESULTS

The combination of simvastatin and FP significantly increased Treg and concomitantly reduced Th17 cell numbers to a greater extent than FP or statin treatment alone. The enhancing effects of simvastatin on FP effects were mediated through the up-regulation of indoleamine 2, 3-dioxygenase and interleukin (IL)-10, together with down-regulation of IL-6 and IL-23 expression in mDCs.

CONCLUSION

On the basis of this in vitro model of asthma, we suggest that the combination of a statin and a corticosteroid could augment the Treg/Th17 cell ratio and thus more effectively suppress airway inflammation in asthma patients. This may be particularly relevant in the treatment of severe asthma where Th17 cells are activated and linked to neutrophilic inflammation.

[Immunoregulatory mechanisms of an optimal Chinese herbal monomer compound in mice with allergic rhinitis]

OBJECTIVE

To study the immunoregulatory effect of an optimal Chinese herbal monomer compound, which consists of three monomers, namely, icariin, baicalin and Astragalus saponin I, in a mouse model of allergic rhinitis.

METHODS

A mouse model of allergic rhinitis was established by intraperitoneal injection of ovalbumin and aluminum hydroxide gel suspension. The splenic lymphocytes of the mice were separated, cultured in 96-well plates and divided into three groups: control group, concanavalin A group and compound group. Splenic lymphocyte proliferation was detected by cell counting kit-8 method at different time points. Cell cycle distribution was observed by flow cytometry (FCM) also at different time points. The changes of intracellular calcium concentration of splenic lymphocytes were measured by fluorescence microplate reader after the cells were incubated with fluorescence probe Fluo-3/AM.

RESULTS

The Chinese herbal monomer compound could inhibit cell proliferation induced by concanavalin A (P<0.01). And the inhibition presented a time-effect relationship. With extending of the action time, the inhibition rate gradually increased and reached peak at the 48th hour. FCM test revealed the fact that concanavalin A could promote cells to enter into the mitosis by reducing the percentage of cells in G0/G1 phases while increasing the percentage of cells in S and G(2)/M phases. Compared with the concanavalin A, the compound could increase the percentage of cells in G(0)/G(1) phases and at the same time reduce the percentage of cells in S and G(2)/M phases at different time points, with the effect most significant at the 24th hour (P<0.05 or P<0.01). The results of the test taken by the fluorescence microplate reader revealed that the fluorescence value of the concanavalin A group increased with time in the previous 24 h while the compound could reduce this trend obviously, thus reduce the intracellular calcium concentration (P<0.01).

CONCLUSION

The Chinese herbal monomer compound can inhibit the proliferation of cultured splenic lymphocytes of mice with allergic rhinitis. The effects of the compound of lowering intracellular calcium concentration and arresting cell cycle at G(0)/G(1) phases from entering into S and G(2)/M phases are responsible for its antiproliferation activity.

Flow cytometry of sputum: assessing inflammation and immune response elements in the bronchial airways

BACKGROUND

The evaluation of sputum leukocytes by flow cytometry (FCM) is an opportunity to assess characteristics of cells residing in the central airways, yet it is hampered by certain inherent properties of sputum including mucus and large amounts of contaminating cells and debris.

OBJECTIVE

To develop a gating strategy based on specific antibody panels in combination with light scatter properties for flow cytometric evaluation of sputum cells.

METHODS

Healthy and mild asthmatic volunteers underwent sputum induction. Manually selected mucus "plug" material was treated with dithiothreitol, filtered and total leukocytes acquired. Multicolor FCM was performed using specific gating strategies based on light scatter properties, differential expression of CD45 and cell lineage markers to discriminate leukocytes from squamous epithelial cells and debris.

RESULTS

The combination of forward scatter and CD45 expression reliably segregated sputum leukocytes from contaminating squamous epithelial cells and debris. Overlap of major leukocyte populations (neutrophils, macrophages/monocytes) required the use of specific antibodies (e.g. CD16, CD64, CD14, HLA-DR) that differentiated granulocytes from monocytes and macrophages. These gating strategies allowed identification of small populations of eosinophils, CD11c+ myeloid dendritic cells, B-cells and natural killer cells.

CONCLUSIONS

Multicolor FCM can be successfully applied to sputum samples to identify and characterize leukocyte populations residing on the surfaces of the central airways.

CLINICAL RELEVANCE

This research describes detailed methods to overcome difficulties associated with FCM of sputum samples, which previously has been lacking in the literature. FCM of sputum samples can provide valuable information on inflammation and immunological response elements in the bronchial airways for both clinical diagnostic and research applications and can be a useful tool in inhalation toxicology for assessing health effects of inhaled environmental pollutants.

Normalization of deranged signal transduction in lymphocytes of COPD patients by the novel calcium channel blocker H-DHPM

Investigations on the role of intracellular Ca(2+) ion concentration in the mechanism of development of COPD in smokers and non-smokers were carried out. The intracellular Ca(2+) levels were found to be increased in human lymphocytes in patients with COPD as compared to non-smokers and smokers without COPD. The investigations reveal an association in altered intracellular Ca(2+) regulation in lymphocytes and severity of COPD, by means of significant activation of Protein kinase C and inducible nitric oxide synthase (iNOS). The effect of a novel calcium channel blocker ethyl 4-(4'-heptanoyloxyphenyl)-6-methyl-3,4-dihydropyrimidin-2-one-5-carboxylate (H-DHPM) as a potential candidate for the treatment of COPD was also investigated. H-DHPM treated cells showed a decrease in intracellular Ca(2+) level as compared to the control cells. Molecular studies were carried out to evaluate the expression profile of NOS isoforms in human lymphocytes and it was shown that H-DHPM decreases the increased iNOS in COPD along with reestablishing the normal levels of endothelial nitric oxide synthase (eNOS). The results of H-DHPM were comparable with those of Amlodipine, a known calcium channel blocker. Calcium channel blocker H-DHPM proves to be a potential candidate for the treatment of COPD and further clinical studies are required to prove its role in the treatment of pulmonary hypertension (PH).

Cytotoxic T cells expressing the co-stimulatory receptor NKG2 D are increased in cigarette smoking and COPD

Background

A suggested role for T cells in COPD pathogenesis is based on associations between increased lung cytotoxic T lymphocyte (CD8⁺) numbers and airflow limitation. CD69 is an early T cell activation marker. Natural Killer cell group 2 D (NKG2D) receptors are co-stimulatory molecules induced on CD8⁺ T cells upon activation. The activating function of NKG2 D is triggered by binding to MHC class 1 chain-related (MIC) molecules A and B, expressed on surface of stressed epithelial cells. The aim of this study was to evaluate the expression of MIC A and B in the bronchial epithelium and NKG2 D and CD69 on BAL lymphocytes in subjects with COPD, compared to smokers with normal lung function and healthy never-smokers.

Methods

Bronchoscopy with airway lavages and endobronchial mucosal biopsy sampling was performed in 35 patients with COPD, 21 healthy never-smokers and 16 smokers with normal lung function. Biopsies were immunohistochemically stained and BAL lymphocyte subsets were determined using flow cytometry.

Results

Epithelial CD3⁺ lymphocytes in bronchial biopsies were increased in both smokers with normal lung function and in COPD patients, compared to never-smokers. Epithelial CD8⁺ lymphocyte numbers were higher in the COPD group compared to never-smoking controls. Among gated CD3⁺cells in BAL, the percentage of CD8⁺ NKG2D⁺ cells was enhanced in patients with COPD and smokers with normal lung function, compared to never-smokers. The percentage of CD8⁺ CD69⁺ cells and cell surface expression of CD69 were enhanced in patients with COPD and smokers with normal lung function, compared to never-smokers. No changes in the expression of MIC A or MIC B in the airway epithelium could be detected between the groups, whereas significantly decreased soluble MICB was detected in bronchial wash from smokers with normal lung function, compared to never-smokers.

Conclusions

In COPD, we found increased numbers of cytotoxic T cells in both bronchial epithelium and airway lumen. Further, the proportions of CD69- and NKG2D-expressing cytotoxic T cells in BAL fluid were enhanced in both subjects with COPD and smokers with normal lung function and increased expression of CD69 was found on CD8⁺ cells, indicating the cigarette smoke exposure-induced expansion of activated cytotoxic T cells, which potentially can respond to stressed epithelial cells.

Noninvasive methods for assessment of airway inflammation in occupational settings

The present document is a consensus statement reached by a panel of experts on noninvasive methods for assessment of airway inflammation in the investigation of occupational respiratory diseases, such as occupational rhinitis, occupational asthma, and nonasthmatic eosinophilic bronchitis. Both the upper and the lower airway inflammation have been reviewed and appraised reinforcing the concept of 'united airway disease' in the occupational settings. The most widely used noninvasive methods to assess bronchial inflammation are covered: induced sputum, fractional exhaled nitric oxide (FeNO) concentration, and exhaled breath condensate. Nasal inflammation may be assessed by noninvasive approaches such as nasal cytology and nasal lavage, which provide information on different aspects of inflammatory processes (cellular vs mediators). Key messages and suggestions on the use of noninvasive methods for assessment of airway inflammation in the investigation and diagnosis of occupational airway diseases are issued.

Chronic obstructive pulmonary disease and neutrophil infiltration: role of cigarette smoke and cyclooxygenase products

Cigarette smoke is the main cause of chronic obstructive pulmonary disease (COPD), where it can contribute to the observed airway inflammation. PGE(2) is produced within human airways, and both pro- and anti-inflammatory activities have been reported. We quantitated PGE(2) concentrations in induced sputum supernatants from different groups of subjects and correlated the obtained values to neutrophil infiltration as well as to the expression of cyclooxygenase-2 (COX-2). Cigarette smoke extract (CSE) was used to evaluate the effect of smoking on COX-2 and PGE(2) receptor expression as well as on PGE(2) release in neutrophils and alveolar macrophages (AM) obtained from normal donors. The effects of PGE(2) and of PGE receptor agonists and antagonists were evaluated on the adhesion of neutrophil to a human bronchial epithelial cell line (16HBE). PGE(2) levels, COX-2 expression, and neutrophil infiltration were significantly higher in normal smokers and COPD smokers (P < 0.0001) compared with controls and COPD former smokers. Induced sputum supernatant caused neutrophil adhesion to 16HBE that was significantly reduced, in COPD smokers only, by PGE(2) immunoprecipitation. In vitro experiments confirmed that CSE increased PGE(2) release and COX-2 and PGE(2) receptor expression in neutrophils and AM; PGE(2) enhanced the adhesion of neutrophils to 16HBE, and a specific E-prostanoid 4 (EP(4)) receptor antagonist blunted its effect. These results suggest that CSE promote the induction of COX-2 and contributes to the proinflammatory effects of PGE(2) in the airways of COPD subjects.

T cells in sputum of asthmatic patients are activated independently of disease severity or control

BACKGROUND

T cells play an important role in bronchial asthma. Although airway CD4+ T cells have been extensively studied previously, there are hardly any studies relating CD8+ T cell activation and disease symptoms.

OBJECTIVES

The aim of this study was to analyse the association between T cell activation in induced sputum T cells and asthma severity and control; and to evaluate T cell subpopulations in the same subgroups.

METHODS

Fifty allergic asthmatic patients were recruited and lung function testing was performed. Airway cells were obtained by sputum induction via inhalation of hypertonic saline solution. CD3, CD4, CD8, CD28, CD25 and CD69 were studied by flow cytometry in whole induced sputum and peripheral blood cells.

RESULTS

Total induced sputum T cells and CD8+ T cells had a higher relative percentage of the activation markers CD25 and CD69 in comparison with peripheral blood. In sputum, the relative percentage of CD25 was higher in CD4+ T cells when compared to CD8+ T cells and the reverse was true regarding CD69. However, neither disease severity nor control were associated with the relative percentage of CD25 or CD69 expression on T cells in sputum.

CONCLUSIONS

Both CD4+ and CD8+ T cells are activated in the lungs and peripheral blood of asthmatic patients. However, with the possible exception of CD69+ CD8+ T lymphocytes in the sputum, there is no association between T cell activation phenotype in the target organ and disease severity or control.

Epithelium, inflammation, and immunity in the upper airways of humans: studies in chronic rhinosinusitis

The purpose of this review is to discuss recent findings made during studies of the upper airways and sinuses of people with chronic rhinosinusitis (CRS) in the context of the literature. CRS is a chronic inflammatory disorder affecting nearly 30 million Americans and is generally resistant to therapy with antibiotics and glucocorticoids (Meltzer EO and coworkers, J Allergy Clin Immunol 2004;114:155-212). We have formed a collaboration that consists of otolaryngologists, allergists, and basic scientists to address the underlying immunologic and inflammatory processes that are occurring in, and possibly responsible for, this disease. The main emphasis of our work has been to focus on the roles that epithelium, in the sinuses and upper airways, plays as both a mediator and regulator of immune and inflammatory responses. It is not our intention here to provide a comprehensive review of the literature in this area, but we will try to put our work in the context of the findings of others (Kato A and Schleimer RP, Curr Opin Immunol 2007;19:711-720; Schleimer RP and coworkers, J Allergy Clin Immunol 2007;120:1279-1284). In particular, we discuss the evidence that epithelial cell responses are altered in CRS, including those relevant to regulation of dendritic cells, T cells, B cells, and barrier function.

Altered effector function of peripheral cytotoxic cells in COPD

Background

There is mounting evidence that perforin and granzymes are important mediators in the lung destruction seen in COPD. We investigated the characteristics of the three main perforin and granzyme containing peripheral cells, namely CD8⁺ T lymphocytes, natural killer (NK; CD56⁺CD3^-) cells and NKT-like (CD56⁺CD3⁺) cells.

Methods

Peripheral blood mononuclear cells (PBMCs) were isolated and cell numbers and intracellular granzyme B and perforin were analysed by flow cytometry. Immunomagnetically selected CD8+ T lymphocytes, NK (CD56⁺CD3^-) and NKT-like (CD56⁺CD3⁺) cells were used in an LDH release assay to determine cytotoxicity and cytotoxic mechanisms were investigated by blocking perforin and granzyme B with relevant antibodies.

Results

The proportion of peripheral blood NKT-like (CD56⁺CD3⁺) cells in smokers with COPD (COPD subjects) was significantly lower (0.6%) than in healthy smokers (smokers) (2.8%, p < 0.001) and non-smoking healthy participants (HNS) (3.3%, p < 0.001). NK (CD56⁺CD3^-) cells from COPD subjects were significantly less cytotoxic than in smokers (16.8% vs 51.9% specific lysis, p < 0.001) as were NKT-like (CD56⁺CD3⁺) cells (16.7% vs 52.4% specific lysis, p < 0.001). Both cell types had lower proportions expressing both perforin and granzyme B. Blocking the action of perforin and granzyme B reduced the cytotoxic activity of NK (CD56⁺CD3^-) and NKT-like (CD56⁺CD3⁺) cells from smokers and HNS.

Conclusion

In this study, we show that the relative numbers of peripheral blood NK (CD56⁺CD3^-) and NKT-like (CD56⁺CD3⁺) cells in COPD subjects are reduced and that their cytotoxic effector function is defective.

Effect of in vitro aspirin stimulation on basophils in patients with aspirin-exacerbated respiratory disease

BACKGROUND

Basophil activation has been implicated in the pathogenesis of aspirin-exacerbated respiratory disease (AERD). However, a comprehensive analysis of basophil responses to aspirin in terms of mediator release, cytokine secretion and increased expression of surface activation markers has not been performed.

OBJECTIVE

To study the in vitro effects of aspirin on the concurrent release of histamine, leukotriene C4 (LTC4) and IL-4 from human basophils and to also evaluate changes in surface activation markers (CD63, CD69 and CD203c) expressed by these cells.

METHODS

Basophil-enriched cell suspensions from 10 patients with AERD and 10 healthy volunteers were incubated with lysine-aspirin for up to 3 h. Cells were analysed for expression of CD63, CD69 and CD203c using flow cytometry. Cell-free supernatants were evaluated for histamine, and LTC4 release and for IL-4 secretion.

RESULTS

Aspirin-induced expression of CD63, CD69 and CD203c yielded 30%, 80% and 70% sensitivity, respectively, but with poor specificity. There was no significant difference in LTC4 synthesis between groups. None of the patients with AERD (or controls) released IL-4 in response to aspirin. A higher dose of 5 mg/mL aspirin-mediated non-specific effects on basophils.

CONCLUSION

Basophil responses to in vitro aspirin challenge are poor indicators of clinical sensitivity. Aspirin activates some basophils by means of mechanisms that differ from the classical IgE-mediated pathway. Our study also shows that the use of 27 mm of aspirin (5 mg/mL) by previous investigators causes non-specific basophil activation, thereby eliminating its usefulness in a cell-based diagnostic test for AERD. Evaluation of in vitro basophil activation has low clinical value in identifying aspirin-induced respiratory reactions.

Peripheral T cell functions correlate with the severity of chronic obstructive pulmonary disease

Adaptive immune processes have been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). We hypothesized that peripheral T cell abnormalities may be present in afflicted patients. We tested this hypothesis by characterizing circulating T cells in COPD patients and correlated these findings with disease severity, smoking status, and use of inhaled glucocorticosteroids (ICS). Compared with normal controls, a lesser proportion of peripheral CD4 T cells from COPD subjects produced IL-10, whereas the CD8 T cells from these patients were more often activated and more frequently produced both IFN-gamma and IL-4. COPD severity was significantly and inversely associated with the proportion of circulating CD4 T cells and directly correlated with CD4 production of IL-2, as well as frequency of CD8 T cell activation and CD8 IFN-gamma production. Adjustments for current smoking status and ICS use by linear regression showed independent, and generally inhibitory, effects of these clinical variables on the abnormal T cell functions of these patients. We conclude that circulating T cells from COPD patients are abnormally activated and elaborate proinflammatory mediators with admixed features of Th1 and Th2 responses. Furthermore, many of these effector processes are significantly correlated with disease severity. These findings further implicate adaptive immune processes in COPD progression and indicate that facile assays of peripheral lymphocytes may provide useful insights into disease mechanisms. Current smoking and ICS use had independent effects on T cell functions among the COPD subjects, illustrating the importance of controlling for clinical parameters as covariates in immunological studies of patients afflicted with this disease.

CD8 chemokine receptors in chronic obstructive pulmonary disease

Increased lung CD8 cells and their expression of chemokine receptors CXCR3 and CCR5 have been previously reported in chronic obstructive pulmonary disease (COPD). Alterations of CD8-CCR3 and -CCR4 expression and their ligands in COPD patients have not been fully investigated. The objective of this study was to assess in COPD patients: (i) broncho-alveolar lavage (BAL) CD8 CCR3 and CCR4 expression in COPD patients; and (ii) airway levels of the CCR3 ligands, CCL11 and CCL5. Multi-parameter flow cytometric analysis was used to assess BAL CD3 and CD8-chemokine receptor expression in COPD patients, smokers and healthy non-smokers (HNS). CCL5 and CCL11 levels were measured in BAL, and from the supernatants of lung resection explant cultures. CD8-CCR3 and -CCR5 expression (means) were increased in COPD patients (22% and 46% respectively) and smokers (20% and 45%) compared with HNS (3% and 22%); P < 0.05 for all comparisons. CD3CXCR3 expression was raised in smokers and COPD while CD8CXCR3 and CD3 and CD8 CCR4 expression was similar between groups. CD8CCR5 expression correlated to smoking pack years (r = 0.42, P = 0.01). COPD explants released more CCL5 compared with smokers (P = 0.02), while there was low level CCL11 production. CD8CCR3 and CCR5 expression appear to be regulated by cigarette smoke exposure. We show that COPD lung tissue released more CCL5, suggesting a role for CCL5-CCR3 signalling in pulmonary CD8 recruitment in COPD.

Cell adhesion antagonists: therapeutic potential in asthma and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) and asthma are inflammatory diseases of the lung where a hallmark feature is excessive leukocyte infiltration that leads to tissue injury. Cell adhesion molecules (e.g. selectins and integrins) play a key role in cell trafficking, and in the lung they regulate leukocyte extravasation, migration within the interstitium, cellular activation, and tissue retention. All selectin family members (including L-selectin, P-selectin, and E-selectin) and many of the beta1 and beta2 integrins appear to be important therapeutic targets, as numerous animal studies have demonstrated essential roles for these cell adhesion molecules in lung inflammation. Not surprisingly, these families of adhesion molecules have been under intense investigation by the pharmaceutical industry for the development of novel therapeutics. Integrins are validated drug targets, as drugs that antagonize integrin alphaIIbbeta3 (e.g. abciximab), integrin alphaLbeta2 (efalizumab), and integrin alpha4beta1 (natalizumab) are currently US FDA-approved for acute coronary syndromes, psoriasis, and multiple sclerosis, respectively. However, none has been approved for indications related to asthma or COPD. Here, we provide an overview of roles played by selectins and integrins in lung inflammation. We also describe recent clinical results (both failures and successes) in developing adhesion molecule antagonists, with specific emphasis on those targets that may have potential benefit in asthma and COPD. Early clinical trials using selectin and integrin antagonists have met with limited success. However, recent positive phase II clinical trials with a small-molecule selectin antagonist (bimosiamose) and a small-molecule integrin alpha4beta1 antagonist (valategrast [R411]), have generated enthusiastic anticipation that novel strategies to treat asthma and COPD may be forthcoming.

Killer cells in chronic obstructive pulmonary disease

COPD (chronic obstructive pulmonary disease) is a treatable and preventable disease state, characterized by progressive airflow limitation that is not fully reversible. It is a current and growing cause of mortality and morbidity worldwide, with the WHO (World Health Organization) projecting that total deaths attributed to COPD will increase by more than 30% in the next 10 years. The pathological hallmarks of COPD are destruction of the lung parenchyma (pulmonary emphysema), inflammation of the central airways (chronic bronchitis) and inflammation of the peripheral airways (respiratory bronchiolitis). The destructive changes and tissue remodelling observed in COPD are a result of complex interactions between cells of the innate and adaptive immune systems. The focus of the present review is directed towards the role of CD8(+) T-lymphocytes, NK (natural killer) cells and NKT cells (NK T-cells). These three classes of killer cell could all play an important part in the pathogenesis of COPD. The observed damage to the pulmonary tissue could be caused in three ways: (i) direct cytotoxic effect against the lung epithelium mediated by the activities of perforin and granzymes, (ii) FasL (Fas ligand)-induced apoptosis and/or (iii) cytokine and chemokine release. The present review considers the role of these killer cells in COPD.

Lung tissue and tumour-infiltrating T lymphocytes in patients with non-small cell lung carcinoma and chronic obstructive pulmonary disease (COPD): moderate/severe versus mild stage of COPD

Cytotoxic CD8+ T cells have been suggested to be key players in the pathogenesis of chronic obstructive pulmonary disease (COPD). We wanted to investigate the phenotype of lung tissue T lymphocytes (LTL) and tumour-infiltrating T lymphocytes (TIL) in smokers with peripheral non-small cell lung carcinoma (NSCLC) with moderate/severe versus mild COPD. Lung tissue and tumour samples were obtained from patients with moderate/severe stage of COPD (n = 10) and from patients with mild stage of COPD (n = 7) at lung resection for a solitary peripheral NSCLC, processed and analysed by flow cytometry. The flow-cytometric results showed that lung tissue T cells, regardless of the severity of COPD, were mostly of the activated phenotype, expressed the CXCR3 chemokine receptor characteristic of type 1 T cells, and did neither significantly differ in the expression of activation markers (CD69, CD25 and HLA-DR), differentiation markers (CD27 and CD28) and chemokine receptors (CXCR3 and CCR4) between the selected groups, nor showed any significant correlation with lung function measured as forced expiratory volume in 1 s (FEV1) or TLCO. Compared with LTL, a significantly greater proportion of TIL expressed the activation markers CD69 and CD25, but a lower proportion showed a fully differentiated CD27- 28- phenotype. We conclude that lung LTL patterns are similar in NSCLC patients with moderate/severe or mild stages of COPD, and are not significantly related to lung function. LTL and TIL possess different phenotype characteristics. The majority of tumour tissue T cells are activated, but it seems that their process of differentiation is incomplete.

T lymphocyte subset profile and serum alpha-1-antitrypsin in pathogenesis of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is an inflammatory disorder characterized by the presence of non-fully reversible airflow limitation. The study was undertaken to investigate the involvement of alpha-1-antitrypsin (alpha(1)AT) and T lymphocyte subsets in the pathogenesis of COPD. Blood samples of 50 subjects, including 25 healthy volunteers and 25 patients with COPD, were analysed. Serum trypsin inhibitory capacity (STIC) was determined by enzymatic assay. CD4(+) and CD8(+) T lymphocytes were enumerated in heparinized blood using a fluorescence activated cell sorter counter. The STIC in COPD patients was found to be decreased significantly than in controls (P < 0.01). In COPD patients with lower expression levels of alpha(1)AT, a highly significant decrease in the number of CD4(+) T lymphocytes (P < 0.0009) and CD4/CD8 ratio was observed compared with control subjects (P < 0.008). The mean +/- standard error of CD8(+) lymphocytes was found to be little different (only marginally decreased) in COPD patients compared to healthy controls; however, an alteration in the individual count of CD8(+) lymphocytes cells was observed in COPD patients. Using linear regression analysis, a negative correlation was observed between STIC and CD4(+) lymphocytes and CD8(+) lymphocytes (r = -0.40, P < 0.04; r = -0.42, P < 0.03, respectively) in COPD patients. An alteration in alpha(1)AT and T lymphocyte subsets in COPD patients suggested that interplay of these factors may be responsible for the progression of COPD.

NKT cells in the induced sputum of severe asthmatics

To determine whether there was a specific inflammatory process in severe asthmatics, the phenotypic characteristics of induced sputum immune cells were analysed among patients with severe asthma. Twenty-two induced sputa (10 severe asthmatics) were studied. Flow cytometric analysis was performed using immune cells of the sputum and monoclonal antibodies to CD3, CD4, CD8, CD56, CD25, and TCRγδ. The number of NKT (CD3⁺CD56⁺) cells was significantly higher in the sputum of severe asthmatics compared with mild asthmatic and healthy control groups (P < .05). CD8⁺CD56⁺ cells were the predominant subtype of the increased NKT cells in severe asthmatics. CD3⁺CD56⁺Vα24⁺, TCRγδ⁺ CD56⁺, and CD4⁺CD25⁺ T cells were significantly increased in severe asthmatic patients. These results suggest that the immunopathogenesis of severe asthmatics vary between severe and mild asthmatics, and that CD8⁺CD56⁺ NKT cells may play an important role in the immunopathogenesis of severe asthma.

Role of 5-Lipoxygenase in IL-13-Induced Pulmonary Inflammation and Remodeling

Exaggerated levels of IL-13 and leukotriene (LT) pathway activation frequently coexist at sites of Th2 inflammation and in tissue fibrotic responses. However, the relationship(s) between the IL-13 and LTs in these responses have not been defined. We hypothesized that the 5-lipoxygenase (5-LO) pathway of LT metabolism plays an important role in the pathogenesis of IL-13-induced chronic inflammation and remodeling. To test this hypothesis, we evaluated the effects of IL-13 on components of the 5-LO metabolic and activation pathways. We also compared the effects of transgenic IL-13 in C57BL/6 mice with wild-type and null 5-LO genetic loci. These studies demonstrate that IL-13 increases the levels of mRNA encoding cytosolic phospholipase A(2), LTA(4) hydrolase, and 5-LO-activating protein without altering the expression of 5-LO, LTC(4) synthase, LTB(4) receptors 1 and 2, and cysteinyl-LT receptors 1 and 2. They also demonstrate that this activation is associated with the enhanced accumulation of LTB(4) but not of cysteinyl-LTs. Furthermore, they demonstrate that this stimulation plays a critical role in the pathogenesis of IL-13-induced inflammation, tissue fibrosis, and respiratory failure-induced death while inhibiting alveolar remodeling. Lastly, mechanistic insights are provided by demonstrating that IL-13-induced 5-LO activation is required for optimal stimulation and activation of TGF-beta(1) and the inhibition of matrix metalloproteinase-12. When viewed in combination, these studies demonstrate that 5-LO plays an important role in IL-13-induced inflammation and remodeling.

Characterization of biliary intra-epithelial lymphocytes at different anatomical levels of intrahepatic bile ducts under normal and pathological conditions: numbers of CD4+CD28- intra-epithelial lymphocytes are increased in primary biliary cirrhosis

Distribution of intra-epithelial lymphocytes along intrahepatic biliary tree (bIEL), and their density and phenotype were examined in normal and diseased livers, particularly in primary biliary cirrhosis (PBC). Immunohistochemically, bIEL were examined in 28 normal livers, 13 cases of chronic viral hepatitis (CVH), 13 cases of PBC, five cases of primary sclerosing cholangitis (PSC), seven cases of extrahepatic biliary obstruction (EBO), and 16 hepatolithiatic livers. In normal livers, bIEL were relatively dense at large and septal bile ducts compared to interlobular ducts. Most of them were positive for CD3 and CD8, while a few were positive for CD4, CD20 and CD57. In CVH, PSC and EBO, neither distribution, phenotype nor density of bIEL differed from normal liver. In hepatolithiasis, numbers of CD8(+)bIEL were increased in stone-containing ducts. In PBC, numbers of CD4(+)CD28(-)bIEL, which are reportedly responsible for target tissue destruction in autoimmune diseases, were markedly increased in damaged interlobular ducts. In conclusion, CD3(+)CD8(+)bIEL may be involved in immune homeostasis of intrahepatic bile ducts in normal livers and in CVH, PSC and EBO. Altered distribution and phenotypes of bIEL in PBC and hepatolithiasis may reflect their participation in biliary lesions. Increased CD4(+)CD28(-)bIEL in damaged bile ducts of PBC may be related to immune-mediated biliary damage.

Selective accumulation of differentiated CD8+ T cells specific for respiratory viruses in the human lung

The lungs are frequently challenged by viruses, and resident CD8⁺ T cells likely contribute to the surveillance of these pathogens. To obtain insight into local T cell immunity to respiratory viruses in humans, we determined the specificity, phenotype, and function of lung-residing CD8⁺ T cells and peripheral blood CD8⁺ T cells in a paired analysis. The lung contained markedly higher frequencies of influenza (FLU)-specific and respiratory syncytial virus (RSV)-specific CD8⁺ T cells when compared with the circulation. This contrasted with an equal distribution of cytomegalovirus- and Epstein-Bar virus–specific CD8⁺ T cells. Noticeably, a substantial fraction of the lung-residing FLU- and RSV-specific CD8⁺ T cells had progressed to a relatively late differentiation phenotype, reflected by low expression of CD28 and CD27. Lung-derived FLU-specific CD8⁺ T cells had low activation requirements, as expansion of these cells could be initiated by cognate peptide in the absence of helper cell–derived signals. Thus, the human lung contains high numbers of differentiated FLU- and RSV-specific memory CD8⁺ T cells that can readily expand upon reexposure to virus. Resident lung T cells may provide immediate immunological protection against pulmonary virus infections.

Comparison of induced sputum inflammatory profiles between childhood and adult-onset asthma

The aim of this study was to investigate differences in airway inflammation between childhood and adult-onset asthma. A total of 47 asthmatic subjects were recruited from patients attending outpatient clinic. A group of 32 adults, mean age 42.8 years (yrs) and a group of 15 children, mean age 11.7 yrs were included. The two groups did not differ in respect to gender, dose of inhaled corticosteroids, atopy status or duration of asthma (mean duration 7.75 yr). Lung function tests, and sputum induction were performed. Flowcytometry was used to study cell population and interleukin-8, eosinophilic cationic protein (ECP) and granulocyte-macrophage colony stimulating factor were measured by enzyme-linked immunosorbent assay (ELISA). Three out of 15 (20%) of the children and 6 out of 32 (19%) of the adult patients were unable to produce a sufficient sputum sample. However, all individuals tolerated the procedure well. The viability of induced sputum cells did not differ among adult-onset asthmatics and children with asthma. Children had greater number of total cells in induced sputum compared with adult subjects (P=0.02). No statistical difference in T-lymphocytes subsets was found between the two groups, except for CD25 (P=0.04). A negative correlation was found between forced expiratory volume (FEV1) values and ECP levels (r=0.338, P=0.04) in the whole population (children and adults). Our study showed that the immunopathology of pediatric and adult asthma is similar and sputum induction provides opportunities for comparison of airway inflammation in childhood and adult asthma safely.

Systemic CD4+ T-cell activation is correlated with FEV1 in smokers

The inflammation of the lungs in chronic obstructive pulmonary disease (COPD) is characterised by increased numbers of macrophages, neutrophils and T-cells. Decline in lung function in these patients has been correlated to the number of CD8+ T-cells present in the lung as well as to a decline in the ratio of CD4+/CD8+ T-cells. Although systemic components are likely to be present, circulating lymphocyte populations in COPD patients have not been well characterised. This study aimed at correlating lung function to expression of five different T-cell activation markers on peripheral blood CD4+ and CD8+ T-cells in COPD patients and matched smokers. Furthermore, proportions of lymphocyte populations and degree of systemic T-cell activation in COPD patients were compared to that in smokers and never-smokers. Peripheral blood lymphocytes from six never-smokers, eight smokers and 17 smokers with COPD were analysed using flowcytometry. The number of lymphocytes per millilitre was higher in smokers than in never-smokers. No differences were found between the three groups in regard to proportions of lymphocyte populations, but the number of CD4+ T-cells in smokers was higher than in both never-smokers and COPD patients. The degree of T-cell activation was similar in all patient groups; however, a clear correlation between CD69 expression on CD4+ T-cells and lung function (FEV(1)% of predicted) was found when examining current smokers, with or without COPD. Elevated numbers of CD69+ CD4+ T-cells in blood thus seem to be protective against airway obstruction in smokers while still exposed to cigarette smoke, the main inducer of COPD.

αEβ7 (CD103) Expression Identifies a Highly Active, Tonsil-Resident Effector-Memory CTL Population

The characterization of antiviral CTL responses has largely been limited to assessing Ag-specific immune responses in the peripheral blood. Consequently, there is an incomplete understanding of the cellular immune responses at mucosal sites where many viruses enter and initially replicate and how the Ag specificity and activation status of CTL derived from these mucosal sites may differ from that of blood-derived CTL. In this study, we show that EBV-specific CTL responses in the tonsils are of comparable specificity and breadth but of a significantly higher magnitude compared with responses in the peripheral blood. EBV-specific, tonsil-resident, but not PBMC-derived, T cells expressed the integrin/activation marker CD103 (alphaEbeta7), consistent with the detection of its ligand, E-cadherin, on tonsillar squamous cells. These CD8-positive, CD103-positive, tonsil-derived CTL were largely CCR7- and CD45RA- negative effector-memory cells and responded to lower Ag concentrations in in vitro assays than their CD103-negative PBMC-derived counterparts. Thus, EBV-specific CTL in the tonsil, a crucial site for EBV entry and replication, are of greater magnitude and phenotypically distinct from CTL in the peripheral blood and may be important for effective control of this orally transmitted virus.

Mediators of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major and increasing global health problem that is now a leading cause of death. COPD is associated with a chronic inflammatory response, predominantly in small airways and lung parenchyma, which is characterized by increased numbers of macrophages, neutrophils, and T lymphocytes. The inflammatory mediators involved in COPD have not been clearly defined, in contrast to asthma, but it is now apparent that many lipid mediators, inflammatory peptides, reactive oxygen and nitrogen species, chemokines, cytokines, and growth factors are involved in orchestrating the complex inflammatory process that results in small airway fibrosis and alveolar destruction. Many proteases are also involved in the inflammatory process and are responsible for the destruction of elastin fibers in the lung parenchyma, which is the hallmark of emphysema. The identification of inflammatory mediators and understanding their interactions is important for the development of anti-inflammatory treatments for this important disease.

αEβ7 Expression on CD8+ T-Cells in COPD BAL Fluid and on TGF-β Stimulated T-Cells In Vitro

The airway inflammation in patients with COPD shows increased numbers of CD8+ T-cells. Until now few studies have shown any functional data indicating a role for these cells in the pathogenesis of COPD. This paper focuses on a subset of CD8+ T-cells present in human lung, the intra-epithelial lymphocytes expressing the integrin alphaEbeta7, and their presence in bronchoalveolar lavage fluid from COPD patients. In this study we demonstrate that 64-89% of the CD8+ T-cells in bronchoalveolar lavage fluid from COPD patients are positive for CD103, the alpha subunit of alphaEbeta7. We also present an in vitro system in which it is possible to differentiate peripheral T-cells into a phenotype resembling the one found in bronchoalveolar lavage fluid, i.e., CD8+ CD103+. In this in vitro system we demonstrate that, in addition to TGF-beta1, cell-to-cell interaction between the T-cell and an antigen-presenting cell represented here by the monocyte, is crucial for a rapid, high and sustained expression of CD103. The signal provided by the monocytes is shown to be mediated through LFA-1 on the T-cell. Furthermore, differentiation of CD8+ T-cells by TGF-beta1 and monocytes results in down regulation of INF-gamma, TNF-alpha and GM-CSF production. IL-8 production is, however, retained in the alphaEbeta7 expressing cells. We see this work as an initiation on the quest for a functional characterization of one of the different types of CD8+ T cells present in COPD. In the longer perspective we hope this can lead to an increased understanding of how these cells can contribute to the disease pathology.

Induced sputum and bronchoalveolar lavage from patients with hypersensitivity pneumonitis

BACKGROUND AND AIM

Hypersensitivity pneumonitis (HP) is an immunologically induced inflammation of the lung parenchyma, though bronchial airways may be also involved. The aim of this study was to compare the cellular profiles of induced sputum (IS) in patients with newly diagnosed HP to that of healthy subjects, and to examine the relationship between inflammatory cells from IS and BAL.

METHODS

Nine HP patients and 9 healthy volunteers were studied. IS was obtained by inhalation of hypertonic saline solution in all subjects. Bronchoscopy was performed on a different occasion in all patients and in five controls.

RESULTS

IS was well tolerated and preferred to BAL by all subjects. Both IS and BAL from HP patients showed a significant increase in total cells (P < 0.02 and P < 0.001) and in lymphocytes (P < 0.02 and P < 0.001) and a significant decrease in macrophages (P < 0.05 and P < 0.001), when compared with normal subjects. In HP patients, total cells number in IS was higher than that in BAL (P < 0.02). Moreover, the percentage of lymphocytes was significantly lower in IS than in BAL (P < 0.001). No significant relationship was found between total cells or inflammatory cells from IS and the corresponding ones from BAL and wide limits of agreement were found between lymphocytes from IS and BAL.

CONCLUSIONS

This study demonstrated that both BAL and IS from newly diagnosed HP patients contained significantly more total cells and lymphocytes, when compared to healthy subjects. Moreover, differential cell counts in HP patients showed that IS and BAL reflected different compartments of inflammation. Thus, IS could represent a complementary, but not alternative tool to bronchoscopy both in research and in the clinical monitoring of HP patients.

CD4 T Lymphocyte–mediated Lung Disease

Although considerable evidence indicates a role for CD4(+) T lymphocytes (T cells) in airway inflammation, little data exist regarding the mechanisms underlying the induction and regulation of CD4(+) T cell reactivity to lung-specific antigens. To dissect the immunologic and molecular mechanisms of CD4(+) T cell dysregulation, reactivity to a self-antigen expressed in the lung of mice bearing a major histocompatibility complex class-II-restricted T cell receptor specific for this antigen was studied. Transgenic mice developed a progressive interstitial pneumonitis characterized by massive lymphocytic and plasmacytic infiltration of interalveolar septa, a clinical picture closely resembling some of the interstitial lung diseases. Pulmonary inflammation reached a plateau state in older mice with prominent formation of lymphoid follicles but reduced interstitial infiltration. Extensive immunologic characterization of self-reactive CD4(+) T cells isolated from the inflamed lung suggested the induction of regulatory T cells in the site of inflammation. Moreover, inflammation was accompanied by broad changes in the gene expression pattern toward a profile partially resembling that of activated, but strikingly, also that of regulatory CD4(+) T cells. Together our data provide important insights into functional and molecular alterations being associated with the induction and/or regulation of T cell-mediated pulmonary inflammation.

Inflammatory cell profiles and T-lymphocyte subsets in chronic obstructive pulmonary disease and severe persistent asthma

BACKGROUND

Severe persistent asthma (SPA) and chronic obstructive pulmonary disease (COPD) are both associated with non-reversible airflow limitation and airway neutrophilia.

OBJECTIVE

To compare inflammatory cell profiles and T lymphocyte subsets between SPA and COPD patients with similar severity of airflow limitation.

METHODS

Sputum induction and lung function tests were performed in 15 COPD patients aged (mean+/-SD) 68+/-8 years, ex-smokers, mean forced expiratory volume in 1 s (FEV1) 45% of predicted (% pred) and 13 SPA aged 55+/-10 years, non-smokers, mean FEV(1) 49% pred. All patients were on inhaled steroid treatment. Eight asthmatics exhibited irreversible airflow limitation. Differential cell count, metachromatic cell count and double immunocytochemistry for the analysis of T lymphocyte subsets were performed on sputum slides.

RESULTS

COPD patients had increased sputum neutrophils in comparison with SPA (P<0.03), but similar to SPA with fixed obstruction. In COPD sputum neutrophils negatively correlated with the lung transfer factor for carbon monoxide (KCO) (r=-0.462, P=0.04). SPA showed significantly increased eosinophils and metachromatic cells vs. COPD patients (P<0.04, P<0.007, respectively). Increased CD4/CD8 and decreased CD4-IFN-gamma/CD4-IL4+ cell ratio (P<0.001) were found in SPA vs. COPD. In SPA, CD4/CD8+ cell ratio correlated with sputum eosinophils (r=0.567, P=0.04).

CONCLUSION

In spite of treatment with inhaled steroids, SPA and COPD exhibit distinct sputum inflammatory cell patterns, although SPA with fixed airflow limitation and COPD patients have similar numbers of neutrophils.

Perforin expression and cytotoxic activity of sputum CD8+ lymphocytes in patients with COPD

BACKGROUND

Previous studies have shown that the inflammatory response to cigarette smoking differs between smokers who acquire COPD and those who do not, and the CD8(+) T- lymphocytes have been identified as a key player in this response.

OBJECTIVE

To investigate the cytotoxic activity and perforin expression of CD8(+) lymphocytes in the airway lumen of patients with COPD.

METHODS

Thirty-six male smokers with COPD, 25 male smokers without COPD, and 10 healthy nonsmokers participated in the study. T-lymphocytes of induced sputum samples were labeled with appropriate monoclonal antibodies and measured using flow cytometry. The cytotoxic activity of CD8(+) cells was defined by incubating them with specific target cells (K562).

RESULTS

The percentage and the total number of CD8(+) lymphocytes were significantly higher in COPD smokers compared to non-COPD smokers (p = 0.01 and p = 0.005, respectively) or to healthy nonsmokers (p = 0.02 and p = 0.01, respectively). Perforin expression in CD8(+) cells was significantly higher in smokers with COPD compared to the other two groups (p = 0.001). Increased cytotoxic activity of T cells was also observed in induced sputum of patients with COPD in comparison to the other two groups.

CONCLUSION

CD8(+) cells are not only increased in number in sputum samples of smokers with COPD but are highly activated, expressing high levels of perforin. These findings suggest that CD8(+) T-lymphocytes play a significant role in the inflammatory process of COPD.

Assessment of T lymphocyte cytokine production in induced sputum from asthmatics: a flow cytometry study

BACKGROUND

Asthma results from a bronchial inflammation in which Th2 lymphocytes play a pivotal role, as shown in invasive bronchial biopsies and broncho-alveolar lavages. Induced sputum (IS) is a non-invasive method of recovery of bronchial cells, which can be repeated in the same patients. However, lymphocyte activation has not been studied in IS to date, because of the low number of T cells recovered. Herein we took advantage of flow cytometry, a method suitable for the study of small cell populations, to assess T cell cytokine production in IS.

OBJECTIVES

(1) To assess induced sputum T cell cytokine production by flow cytometry in asthmatic subjects and controls. (2) To compare the T cell cytokine production between symptomatic and non-symptomatic asthmatics.

METHODS

Thirteen asthmatics and 19 controls were included. Sputum was induced by a hypertonic saline. Sputum cells were stimulated and intracellular IL-13 and IFN-gamma were detected in T cells by flow cytometry.

RESULTS

Stimulation induced an increase of IL-13 and IFN-gamma production by T cells. This increase was higher in asthmatics. IL-13-producing T cells were increased in asthmatics after stimulation. In symptomatic asthma, IFN-gamma-producing T cells were in higher proportion than in controlled asthma.

CONCLUSION

IS T cell cytokine production indicates a basic Th2 bias in asthma, accompanied during symptoms by a Th1-like activation. These results open the field for longitudinal studies of the variation of T cell activation in asthma.