Dendritic cell phenotype in severe asthma reflects clinical responsiveness to glucocorticoids.

BACKGROUND: Subsets of patients with severe asthma remain symptomatic despite prolonged, high-dose glucocorticoid therapy. We hypothesized that the clinical glucocorticoid sensitivity of these asthmatics is reflected in differences in peripheral blood dendritic cell subsets. OBJECTIVE: To compare peripheral blood leucocyte populations using flow cytometry at baseline and after 2 weeks of systemic glucocorticoid (steroid) treatment to identify immunological differences between steroid-sensitive (SS) and steroid-resistant (SR) asthmatics. METHODS: Adult severe asthmatics (SS n = 12; SR n = 23) were assessed for their response to 2 weeks of therapy with oral prednisolone. Peripheral blood was obtained before and after therapy and stained for lymphocyte (CD3, CD19, CD4, CD8 and Foxp3) and dendritic cell markers (Lineage negative [CD3, CD14, CD16, CD19, CD20, CD56], HLA-DR+, CD304, CD11c, ILT3 and CD86). RESULTS: A higher median frequency of myeloid DCs (mDCs) but not plasmacytoid DCs (pDCs) was observed in the blood of SR as compared to SS asthmatics (P = .03). Glucocorticoid therapy significantly increased median B cell, but not T cell numbers in both cohorts, with a trend for increased numbers of Foxp3+ Tregs in SS (P = .07), but not SR subjects. Oral prednisolone therapy significantly reduced the median numbers and frequencies of total DCs and pDCs in both SS and SR asthmatics. Interestingly, the expression of HLA-DR and ILT3 was also reduced on pDCs in all patients. In contrast, therapy increased the median frequency of mDCs in SS, but reduced it in SR asthmatics. CONCLUSIONS: Myeloid DC frequency is elevated in SR compared with SS asthmatics, and mDC shows a differential response to oral prednisolone therapy.

An immunologically relevant rodent model demonstrates safety of therapy using a tumour-specific IgE.

BACKGROUND: Designing biologically informative models for assessing the safety of novel agents, especially for cancer immunotherapy, carries substantial challenges. The choice of an in vivo system for studies on IgE antibodies represents a major impediment to their clinical translation, especially with respect to class-specific immunological functions and safety. Fcε receptor expression and structure are different in humans and mice, so that the murine system is not informative when studying human IgE biology. By contrast, FcεRI expression and cellular distribution in rats mirror that of humans. METHODS: We are developing MOv18 IgE, a human chimeric antibody recognizing the tumour-associated antigen folate receptor alpha. We created an immunologically congruent surrogate rat model likely to recapitulate human IgE-FcεR interactions and engineered a surrogate rat IgE equivalent to MOv18. Employing this model, we examined in vivo safety and efficacy of antitumour IgE antibodies. RESULTS: In immunocompetent rats, rodent IgE restricted growth of syngeneic tumours in the absence of clinical, histopathological or metabolic signs associated with obvious toxicity. No physiological or immunological evidence of a "cytokine storm" or allergic response was seen, even at 50 mg/kg weekly doses. IgE treatment was associated with elevated serum concentrations of TNFα, a mediator previously linked with IgE-mediated antitumour and antiparasitic functions, alongside evidence of substantially elevated tumoural immune cell infiltration and immunological pathway activation in tumour-bearing lungs. CONCLUSION: Our findings indicate safety of MOv18 IgE, in conjunction with efficacy and immune activation, supporting the translation of this therapeutic approach to the clinical arena.

Expression of IL-17A, E, and F and their receptors in non-small-cell lung cancer.

Lung cancer is the leading cause of cancer-related morbidity and mortality worldwide. Interaction of nascent or established lung tumour cells with various cytokines and infiltrating immune cells has been implicated in lung cancer pathogenesis. In this study, we systematically analysed immunoreactivity for IL-17A, IL-17E and IL-17F and their relevant receptors in the lung sections from non-small cell lung cancer (NSCLC) and normal control. Immunoreactivity for IL-17A, IL-17F, IL-17RA and IL- 17RC, but not IL-17RB was significantly elevated in NSCLC compared with controls, while IL-17E was reduced. The median numbers of infiltrating lymphocytes and neutrophils and global macrophage (CD68) immunoreactivity of phagocytes were also elevated in NSCLC compared with control tissue sections. Furthermore, correlation between the expression of IL-17A and its receptors IL-17RA and IL- 17RC varied according to NSCLC histopathological type. These data suggest that IL-17A, E, F and their receptors IL-17RA, RB, RC may be involved in the pathogenesis of NSCLC. Further understanding of the relationship between the IL-17/IL-17R axis and the tumour inflammatory microenvironment may reveal new therapeutic targets.

Cigarette smoking increases bronchial mucosal IL-17A expression in asthmatics, which acts in concert with environmental aeroallergens to engender neutrophilic inflammation.

BACKGROUND: Mild asthmatics who smoke cigarettes may develop unstable disease and neutrophilic infiltration of the airways, features more usually associated with severe asthmatic disease. The mechanisms giving rise to this response remain unclear. OBJECTIVE: To address the hypothesis that smoking increases bronchial mucosal production of IL-17A which acts on bronchial epithelial cells directly and in concert with other environmental stimuli to induce the production of IL-6 and neutrophil chemotaxins. METHODS: IL-17A, IL-8, IL-6, neutrophils and eosinophils were detected and quantified by immunohistochemistry in endobronchial biopsy sections from smoking and non-smoking asthmatics. Human tracheal epithelial cells (HTEpC) were cultured with IL-17A in the presence/absence of cigarette smoke extract (CSE) and aeroallergens lacking intrinsic protease activity, and IL-6 and IL-8 production measured in vitro. RESULTS: Expression of IL-17A, IL-6 and IL-8 and neutrophil numbers was significantly elevated in the bronchial mucosa of the asthmatic smokers compared to the non-smokers. Expression of IL-17A correlated with that of IL-8 and neutrophil numbers. In the smoking asthmatics, eosinophil numbers also correlated with expression of IL-8 and IL-17A. Exposure of HTEpC cells to both CSE and IL-17A increased expression of IL-6 and IL-8 in a concentration-dependent and synergistic manner. Co-stimulation with CSE, IL-17A and aeroallergens further increased IL-6 and IL-8 production synergistically. CONCLUSIONS: The data support the hypothesis that asthmatic smokers develop neutrophilic inflammation of the airways propagated at least partly by smoke-induced production of IL-17A which together with smoke and other environmental stimuli acts on airways epithelial cells to induce neutrophil chemotaxins.

AllergoOncology - the impact of allergy in oncology: EAACI position paper.

Th2 immunity and allergic immune surveillance play critical roles in host responses to pathogens, parasites and allergens. Numerous studies have reported significant links between Th2 responses and cancer, including insights into the functions of IgE antibodies and associated effector cells in both antitumour immune surveillance and therapy. The interdisciplinary field of AllergoOncology was given Task Force status by the European Academy of Allergy and Clinical Immunology in 2014. Affiliated expert groups focus on the interface between allergic responses and cancer, applied to immune surveillance, immunomodulation and the functions of IgE-mediated immune responses against cancer, to derive novel insights into more effective treatments. Coincident with rapid expansion in clinical application of cancer immunotherapies, here we review the current state-of-the-art and future translational opportunities, as well as challenges in this relatively new field. Recent developments include improved understanding of Th2 antibodies, intratumoral innate allergy effector cells and mediators, IgE-mediated tumour antigen cross-presentation by dendritic cells, as well as immunotherapeutic strategies such as vaccines and recombinant antibodies, and finally, the management of allergy in daily clinical oncology. Shedding light on the crosstalk between allergic response and cancer is paving the way for new avenues of treatment.

The Perception of Art among Patients and Staff on a Renal Dialysis Unit.

This study investigated the purpose and effectiveness of giving outpatients an opportunity to engage in art activities while receiving dialysis treatment. A mixed method study was conducted. 21 semi-structured interviews were conducted with outpatients attending the dialysis unit and 13 surveys of clinicians were completed. The principle reasons to partake in the art activity programme included: to pass time, to relieve boredom, to be creative, to try something new, distraction from concerns, to stay positive and to achieve something new. Patients who did not participate in the programme pass their time primarily by watching TV or sleeping. All staff who partook in the survey were satisfied with the programme and wanted it to continue. Our findings indicate that the creative arts programme is viewed positively by staff and patients alike, and might be useful in other hospital departments. Further in depth qualitative research would be useful to interrogate the potential effect of engagement in art on positive mental health and quality of life for patients with chronic conditions.

Resistin-like molecule-ß (RELM-ß) targets airways fibroblasts to effect remodelling in asthma: from mouse to man.

BACKGROUND: RELM-ß has been implicated in airways inflammation and remodelling in murine models. Its possible functions in human airways are largely unknown. The aim was to address the hypothesis that RELM-ß plays a role in extracellular matrix deposition in asthmatic airways. METHODS: The effects of RELM-ß gene deficiency were studied in a model of allergen exposure in mice sensitised and challenged with Aspergillus fumigatus (Af). RELM-ß expression was investigated in bronchial biopsies from asthmatic patients. Direct regulatory effects of RELM-ß on human lung fibroblasts were examined using primary cultures and the MRC5 cell line in vitro. RESULTS: Sensitisation and challenge of wild-type mice with Af-induced release of RELM-ß with a time course coincident with that of procollagen in the airways. Af-induced expression of mRNA encoding some, but not all ECM in the lung parenchyma was attenuated in RELM-ß-/- mice. RELM-ß expression was significantly increased in the bronchial submucosa of human asthmatics compared with controls, and its expression correlated positively with that of fibronectin and α-smooth muscle actin. In addition to epithelial cells, macrophages, fibroblasts and vascular endothelial cells formed the majority of cells expressing RELM-ß in the submucosa. Exposure to RELM-ß increased TGF-ß1, TGF-ß2, collagen I, fibronectin, smooth muscle α-actin, laminin α1, and hyaluronan and proteoglycan link protein 1 (Hapl1) production as well as proliferation by human lung fibroblasts in vitro. These changes were associated with activation of ERK1/2 in MRC5 cells. CONCLUSION: The data are consistent with the hypothesis that elevated RELM-ß expression in asthmatic airways contributes to airways remodelling at least partly by increasing fibroblast proliferation and differentiation with resulting deposition of extracellular matrix proteins.

Direct comparison of the dynamics of IL-25- and 'allergen'-induced airways inflammation, remodelling and hypersensitivity in a murine asthma model.

BACKGROUND: Interleukin-25 has been implicated in the pathogenesis of asthma from studies on human asthmatics and in murine asthma models. OBJECTIVES: In this study, we hypothesized that chronic exposure of the airways to IL-25 alone is able to induce pathogenic changes observed in animal models of asthma. METHODS: We performed a detailed comparison of the dynamics of development of cellular infiltration, cytokine expression and airways remodelling and hyperresponsiveness in mice sensitized and challenged with OVA, a classical model of allergic asthma and those exposed to IL-25 alone. RESULTS: Intranasal challenge of BALB/c mice with IL-25 alone induced a delayed (compared with OVA-challenge), predominantly eosinophilic and lymphocytic infiltration into the airways lumen, along with increased production of Th2-type cytokines, chemokines and collagen, secretion of epithelial mucus, goblet cell hyperplasia, deposition of subepithelial collagen, airways smooth muscle cell hyperplasia and angiogenesis. Correspondingly, IL-25 as well as OVA challenge both induced airways hyperresponsiveness and increased lung tissue damping. In contrast, IL-25 exposure did not increase IgE or IgG1 production. CONCLUSIONS AND CLINICAL RELEVANCE: The data suggest that chronic airways exposure to IL-25 alone is sufficient to induce allergen- and IgE-independent, asthma-like airways inflammation, remodelling and hyperresponsiveness in mice. Thus, IL-25 is a key molecular target in asthma, irrespective of the coexistence of IgE-dependent mechanisms.

Sphingosine-1-phosphate induces pro-remodelling response in airway smooth muscle cells.

BACKGROUND: Increased proliferation of airway smooth muscle (ASM) cells leading to hyperplasia and increased ASM mass is one of the most characteristic features of airway remodelling in asthma. A bioactive lipid, sphingosine-1-phosphate (S1P), has been suggested to affect airway remodelling by stimulation of human ASM cell proliferation. OBJECTIVE: To investigate the effect of S1P on signalling and regulation of gene expression in ASM cells from healthy and asthmatic individuals. METHODS: Airway smooth muscle cells grown from bronchial biopsies of healthy and asthmatic individuals were exposed to S1P. Gene expression was analysed using microarray, real-time PCR and Western blotting. Receptor signalling and function were determined by mRNA knockdown and intracellular calcium mobilization experiments. RESULTS: S1P potently regulated the expression of more than 80 genes in human ASM cells, including several genes known to be involved in the regulation of cell proliferation and airway remodelling (HBEGF, TGFB3, TXNIP, PLAUR, SERPINE1, RGS4). S1P acting through S1P2 and S1P3 receptors activated intracellular calcium mobilization and extracellular signal-regulated and Rho-associated kinases to regulate gene expression. S1P-induced responses were not inhibited by corticosteroids and did not differ significantly between ASM cells from healthy and asthmatic individuals. CONCLUSION: S1P induces a steroid-resistant, pro-remodelling pathway in ASM cells. Targeting S1P or its receptors could be a novel treatment strategy for inhibiting airway remodelling in asthma.

Epidemiological associations of allergy, IgE and cancer.

Several epidemiological studies have evaluated potential associations between allergy and risk of malignancy. It remains clear that the relationship between allergy and cancer is complex. Three hypotheses have been proposed to account for observed relationships: these are chronic inflammation, immunosurveillance, prophylaxis, and we propose adding a fourth: inappropriate T-helper 2 (Th2) immune skewing. Each of these attempts to explain either the increased or decreased risk of different cancer types in 'allergic' patients reported in the literature. All four hypotheses are based on known mechanisms of allergic inflammation and/or IgE antibody functions, and uphold the view of an immunological basis for the relationship between allergy and malignancies. This review summarizes and draws conclusions from the epidemiological literature examining the relationships between specific types of cancer and allergic diseases. Particular emphasis is placed on the most recent contributions to the field, and on consideration of the allergic immune mechanisms that may influence positive or negative associations.

Resistin-like molecule-ß is a human airway remodelling mediator.

Though implicated in vascular remodelling, a role for the resistin-like molecule (RELM)-ß in human airway remodelling remains unexplored. We hypothesised that RELM-ß expression is increased in the airways of asthmatics and regulates airways epithelial cell function. Expression of RELM-ß in the bronchial mucosa and its concentrations in bronchoalveolar lavage (BAL) fluid from asthmatics and controls were measured by immunohistochemistry and ELISA, respectively. Proliferation assays, Western blotting, ELISA and real-time PCR were employed to detect effects of RELM-ß on airways epithelial cells. RELM-ß expression was increased in the bronchial mucosa and BAL fluid of asthmatics compared with controls. In the asthmatics, the numbers of mucosal RELM-ß+ cells correlated inversely with forced expiratory volume in 1 s (r=-0.531, p=0.016), while the numbers of epithelial RELM-ß+ cells correlated positively with those of mucin (MUC)5AC+ cells. In vitro, interleukin-13 enhanced RELM-ß expression by primary human airways epithelial cells, while RELM-ß itself acted on these cells to induce proliferation, expression of MUC5AC, extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK)-phosphatidylinositol 3-kinase (PI3K)/Akt phosphorylation and elevated expression of transforming growth factor-ß2, epidermal growth factor and vascular endothelial growth factor. RELM-ß has the potential to contribute to airway remodelling in diseases such as asthma by acting on epithelial cells to increase proliferation, mucin and growth factor production, at least partly via ERK/MAPK-PI3K/Akt signalling pathways.

Interleukin-25 promotes basic fibroblast growth factor expression by human endothelial cells through interaction with IL-17RB, but not IL-17RA.

BACKGROUND: Unlike other IL-17 family members, the Th2-derived cytokine IL-25 (IL-17E) induces (promotes) Th2 responses. One or both of the two receptors for IL-25 (IL-17RA, IL-17RB) is expressed on inflammatory cells and tissue structural cells, suggesting that in addition to promoting Th2-type inflammation IL-25 may also act on structural cells at sites of Th2-type inflammation such as in the asthmatic bronchial mucosa to promote remodelling changes. OBJECTIVE: Our previous studies showed elevated expression of IL-25 and IL-17RB immunoreactivity in asthmatic airways with co-localization of the latter to endothelial cells. We therefore hypothesized that IL-25 acts on endothelial cells through this receptor to induce production of the key angiogenic and remodelling cytokine basic fibroblast growth factor (bFGF). METHODS: Polymerase chain reaction (PCR) immunocytochemistry/immunohistochemistry and ELISA were employed to detect expression of IL-17RB, IL-17RA and bFGF by human vascular endothelial cells (HUVEC) and immunoreactivity for IL-25 and bFGF in asthmatic bronchial biopsies. Receptor-blocking antibodies, PCR and an in vitro angiogenesis assay were used to investigate whether IL-25 acts on IL-17RB or IL-17RA to induce bFGF expression and angiogenesis. PCR was also employed to investigate the signalling pathways involved in IL-25-mediated bFGF expression. RESULTS: HUVEC constitutively expressed IL-17RB, IL-17RA and bFGF. Production of the latter was further increased by IL-25, but attenuated after blockade of the IL-17RB, but not the IL-17RA receptor. Neutralization of endogenous VEGF and bFGF completely abrogated IL-25-induced angiogenesis which was also inhibited by blocking IL-17RB, but not IL-17RA. The PI3K-specific inhibitor LY294002 also completely attenuated IL-25-induced bFGF expression. Immunoreactivity for IL-25 and bFGF was elevated in the asthmatic bronchial mucosa and the expression of each correlated with the other. CONCLUSIONS AND CLINICAL RELEVANCE: Our data support the hypothesis that IL-25 contributes to elevated bFGF in asthmatic airways by acting on the endothelial cell IL-17RB receptor through PI3K-signalling pathways. Targeting the pathways might benefit therapy of airways remodelling.

T cells producing the anti-inflammatory cytokine IL-10 regulate allergen-specific Th2 responses in human airways.

BACKGROUND: Murine models suggest a critical functional role for the anti-inflammatory cytokine IL-10 in local regulation of allergic airways inflammation. There is little corresponding information on human airway cells. This study aimed to investigate whether local IL-10 production regulates responses by respiratory mucosal leucocytes isolated from nasal polyps. MATERIALS AND METHODS: Nasal polyp tissue was harvested from 24 patients sensitised to aeroallergens with chronic rhinitis and polyposis undergoing routine polypectomy. Cells were isolated by matrix proteolysis. Cytokine production by polyp cells was determined by cytometric bead array (CBA) and intracellular cytokine analysis. Surface marker expression by polyp cells was determined by flow cytometry. RESULTS: Allergen stimulation significantly enhanced production of IL-10, but not IL-5 or IFN-γ by nasal polyp cell suspensions. Under the same conditions, neutralisation of IL-10 significantly increased allergen-specific IL-5 and IFN-γ production by nasal polyp cells. Cell depletion experiments showed that T cells themselves were primarily responsible for IL-10 production or for inducing its production by other cells. Intracellular cytokine staining confirmed production of IL-10 in the absence of IL-2 production by T cells in response to allergen. CONCLUSION: T cells within the human respiratory mucosa produce IL-10, which is capable of inhibiting pro-inflammatory Th2 and Th1 cytokine production in an antigen-specific fashion.

Immunotherapy for allergic rhinitis.

Allergic rhinitis (AR) affects more than 20% of the population in the United Kingdom and western Europe and represents a major cause of morbidity that includes interference with usual daily activities and impairment of sleep quality. This guidance prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) is for the management of AR in patients that have failed to achieve adequate relief of symptoms despite treatment with intranasal corticosteroids and/or antihistamines. The guideline is based on evidence and is for use by both adult physicians and paediatricians practising allergy. During the development of these guidelines, all BSACI members were included in the consultation process using a web-based system. Their comments and suggestions were carefully considered by the SOCC. Where evidence was lacking, consensus was reached by the experts on the committee. Included in this guideline are indications and contraindications for immunotherapy, criteria for patient selection, the evidence for short- and long-term efficacy of subcutaneous and sublingual immunotherapy, and discussion on safety and the different modes of immunotherapy including, pre-seasonal and co-seasonal treatments. There are sections on children, allergen standardization, vaccines used in the United Kingdom, oral allergy syndrome, cost effectiveness of immunotherapy and practical considerations of undertaking immunotherapy including recommendations on who should undertake immunotherapy and dosing schedules. Finally, there is discussion on potential biomarkers of response to immunotherapy, the use of component-resolved diagnostics, novel approaches, alternative routes and potential areas for future research.

Harnessing engineered antibodies of the IgE class to combat malignancy: initial assessment of FcɛRI-mediated basophil activation by a tumour-specific IgE antibody to evaluate the risk of type I hypersensitivity.

BACKGROUND: IgE antibodies, sequestered into tissues and retained locally by the high-affinity IgE receptor, FcɛRI, on powerful effector cells such as mast cells, macrophages and eosinophils, may offer improvements in the therapy of solid tumours. The chimeric antibody, MOv18 IgE, against the human ovarian carcinoma antigen, folate receptor α (FRα), is more effective than its IgG1 counterpart in xenograft models of ovarian cancer. Although MOv18 IgE binds to a single epitope on FRα and cannot cross-link IgE receptors on basophils, there remains a risk that components in the circulation of ovarian cancer patients might cross-link FRα-MOv18-IgE-receptor-FcɛRI complexes on basophils to cause type I hypersensitivity. OBJECTIVE: To assess the propensity for MOv18 used in a therapeutic setting to cause FcɛRI-mediated type I hypersensitivity. METHODS: As validated readouts of the potential for MOv18 to cause FcɛRI-mediated type I hypersensitivity we measured release of a granule-stored mediator from a rat basophilic leukaemia cell line RBL SX-38 stably transfected with human tetrameric (αßγ2) FcɛRI, and induction of CD63 on blood basophils from patients with ovarian carcinoma and healthy controls ex vivo. RESULTS: Serum FRα levels were increased in ovarian cancer patients compared with healthy controls. MOv18 IgE alone, or in the presence of its antigen recombinant human FRα, or of healthy volunteer (n=14) or ovarian carcinoma patient (n=32) sera, did not induce RBL SX-38 cell degranulation. Exposure to FRα-expressing ovarian tumour cells at target-to-effector ratios expected within tumours induced degranulation. MOv18 IgE did not induce expression of CD63 in blood basophils from either healthy volunteers (n=6), or cancer patients, despite detectable levels of circulating FRα (n=5). CONCLUSION AND CLINICAL RELEVANCE: These encouraging data are compatible with the hypothesis that, when ovarian carcinoma patients are treated with MOv18, FcɛRI-mediated activation of effector cells occurs within the tumour mass but not in the circulation mandating, with due caution, further pre-clinical studies.

Simultaneous observations of aerosol-cloud-albedo interactions with three stacked unmanned aerial vehicles.

Aerosol impacts on climate change are still poorly understood, in part, because the few observations and methods for detecting their effects are not well established. For the first time, the enhancement in cloud albedo is directly measured on a cloud-by-cloud basis and linked to increasing aerosol concentrations by using multiple autonomous unmanned aerial vehicles to simultaneously observe the cloud microphysics, vertical aerosol distribution, and associated solar radiative fluxes. In the presence of long-range transport of dust and anthropogenic pollution, the trade cumuli have higher droplet concentrations and are on average brighter. Our observations suggest a higher sensitivity of radiative forcing by trade cumuli to increases in cloud droplet concentrations than previously reported owing to a constrained droplet radius such that increases in droplet concentrations also increase cloud liquid water content. This aerosol-cloud forcing efficiency is as much as -60 W m(-2) per 100% percent cloud fraction for a doubling of droplet concentrations and associated increase of liquid water content. Finally, we develop a strategy for detecting aerosol-cloud interactions based on a nondimensional scaling analysis that relates the contribution of single clouds to albedo measurements and illustrates the significance of characterizing cloud morphology in resolving radiometric measurements. This study demonstrates that aerosol-cloud-albedo interactions can be directly observed by simultaneous observations below, in, and above the clouds.

A novel technique to explore the functions of bronchial mucosal T cells in chronic obstructive pulmonary disease: application to cytotoxicity and cytokine immunoreactivity.

Bronchial mucosal CD8(+) cells are implicated in chronic obstructive pulmonary disease (COPD) pathogenesis, but there are few data on their functional properties. We have developed a novel technique to outgrow these cells from COPD patients in sufficient numbers to examine effector functions. Endobronchial biopsies from 15 COPD smokers and 12 ex-smokers, 11 control smokers and 10 non-smokers were cultured with anti-CD3/interleukin (IL)-2 ± IL-15. Outgrown CD3(+) T cells were characterized in terms of phenotype (expression of CD4, 8, 25, 28, 69 and 56), cytotoxicity and expression of COPD-related cytokines. Compared with IL-2 alone, additional IL-15 increased the yield and viability of biopsy-derived CD3(+) T cells (12-16-day culture without restimulation) without alteration of CD4(+) /CD8(+) ratios or expression of accessory/activation molecules. Biopsy-derived T cells, principally CD8(+)/CD56(+) cells, exhibited statistically significantly greater cytotoxic activity in current or ex-smokers with COPD compared with controls (P < 0·01). Elevated percentages of CD8(+) T cells expressed interferon (IFN)-γ, tumour necrosis factor (TNF)-α and IL-13 (P < 0·01) in current COPD smokers compared with all comparison groups. It is possible to perform functional studies on bronchial mucosal T cells in COPD. We demonstrate increased CD8(+)CD56(+) T cell cytotoxic activity and expression of remodelling cytokines in smokers who develop COPD.

Counter regulation of the high affinity IgE receptor, FcepsilonRI, on human airway dendritic cells by IL-4 and IL-10.

BACKGROUND: Immunoglobulin E is a signalling molecule within the environment of the respiratory tract, the high affinity receptor for which, FcepsilonRI, is expressed by dendritic cells (DC). Little is known, however, of the expression and function of FcepsilonRI on DC in the human respiratory tract. METHODS: CD1c(+) DC were purified from surgically resected nasal turbinates of 11 atopic and 12 nonatopic patients with chronic rhinosinusitis. Expression of FcepsilonRI was determined by flow cytometry. Cytokine production by DC was determined by cytometric bead array. RESULTS: Expression of FcepsilonRI was significantly elevated on respiratory tract dendritic cells (RTDC) from atopic as compared to nonatopic patients. Activation of RTDC through FcepsilonRI induced production of the pro-inflammatory cytokines IL-6 and TNF-alpha, and the anti-inflammatory cytokine IL-10. The production of IL-6 and TNF-alpha was elevated in atopic compared to nonatopic patients studied. Conversely IL-10 production was elevated in nonatopic patients. Concomitant activation of FcepsilonRI and stimulation of RTDC with IL-4 inhibited production of IL-10 by RTDC. Neutralization experiments with anti-IL-10 Ab enhanced whereas addition of exogenous IL-10 to RTDC inhibited FcepsilonRI-mediated inflammatory cytokine production. CONCLUSION: The function of FcepsilonRI on RTDC from patients with rhinosinusitis is susceptible to counter regulation by IL-4 and IL-10.