Biomedical subjects

Q Hamid

Publications and source records attributed to Q Hamid.

At least 109 records · Page 6Linked to original sources

PubMed1997

Immunohistochemical characterization of inflammatory and proliferative events during chronic rejection in rat lung allografts.

BACKGROUND: Chronic rejection is assumed to be the principle cause of airway injury leading to obliterative bronchiolitis (OB) after lung transplantation (Tx). To better understand the contribution of chronic rejection in the development of OB in allografted lungs, we examined the histopathological changes and cytokine expression in inadequately immunosuppressed rat lung allografts. METHODS: Three groups of rats were studied: group I, control nontransplanted Lewis (Lew) rats (n=5); group II, syngeneic Lew-to-Lew isografts (n=25); and group III, Brown Norway-to-Lew allografts (n=25). Groups II and III received two single doses of cyclosporine on postoperative days 2-3. Transplanted animals were killed (n=5) at monthly intervals from 2 months to 6 months after Tx. Resected lungs were stained with hematoxylin and eosin, Masson's trichrome, and Van Gieson's elastin, and immunostained with antisera to interleukin (IL)-1beta, IL-8, and basic fibroblast growth factor (bFGF). The intensity of immunostaining was graded from 0 to 4 (0=no staining, 4=strong staining). RESULTS: In groups I and II, normal airways and vessels were observed. Minimal intensity and distribution of immunostaining for all markers were detected in groups I and II. Group III allografts demonstrated acute grade II-III vascular rejection with mild bronchiolar injury and inflammation at 2 months after Tx. At 6 months after Tx, all allografts demonstrated severe and diffuse chronic vascular rejection. Late airway changes consistent with OB were detected in four of five allografts, however, these lesions were expressed infrequently. Immunohistochemical findings revealed moderate to strong expression for IL-8 and bFGF over the airway epithelium, acute and chronic inflammatory cells, and fibroblasts in allografts at 2 months after Tx. Despite focal development of OB at 6 months, intensity and distribution of immunostaining significantly decreased for all three cytokine markers. CONCLUSIONS: Inadequate immunosuppression of rat lung allografts leads primarily to chronic vascular rejection but fails to induce severe and diffuse development of OB. In this animal model, cytokines IL-1beta, IL-8, and bFGF are likely to play an important role in the early inflammatory phase but not during the late proliferative events of chronic rejection.

Animals↗

PubMed1997

Upregulation of alpha GM-CSF-receptor in nonatopic asthma but not in atopic asthma.

BACKGROUND: Intrinsic asthma is characterized by an increased number of activated eosinophils and macrophages and an increased expression of the hematopoietic growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF) in the bronchial mucosa. OBJECTIVE: This study was carried out to investigate the expression of alpha GM-CSF receptor (alpha GM-CSFr) messenger RNA and protein in the bronchial mucosa of patients with intrinsic or atopic asthma and of control subjects and to correlate the expression of alpha GM-CSFr to the number of EG2+ cells (eosinophils) and CD68+ cells (macrophages) and pulmonary function. METHODS: Nineteen patients with stable asthma (9 with atopic and 10 with intrinsic asthma) and 22 normal control subjects (12 atopic and 10 nonatopic subjects) were recruited, and FEV1 (percent predicted) and PC20 were measured before bronchoscopy. Endobronchial biopsy specimens were obtained and examined for membrane-bound alpha GM-CSFr by using in situ hybridization and immunocytochemistry. RESULTS: alpha GM-CSFr mRNA- and protein-positive cells were identified in biopsy specimens from all four groups studied. There was no significant difference in the number of cells expressing alpha GM-CSFr mRNA and protein in patients with atopic asthma compared with atopic and nonatopic control subjects. However, the numbers of alpha GM-CSFr mRNA- and protein-positive cells were significantly higher in nonatopic patients with asthma compared with atopic patients with asthma and atopic and nonatopic control subjects (p < 0.001). In the patients with intrinsic asthma, the number of alpha GM-CSFr mRNA-positive cells per millimeter of basement membrane correlated with numbers of CD68+ cells (r2 = 0.87, p < 0.001) but not with EG2+ cells, and colocalization studies demonstrated that 80% of the cells expressing alpha GMCSFr mRNA were CD68+. The expression of GM-CSF was also significantly increased in patients with intrinsic asthma compared with those with atopic asthma and control subjects (p < 0.05). In addition, in intrinsic asthma, there was a correlation between alpha GM-CSFr mRNA and FEV1 (r2 = 0.61, p < 0.05). CONCLUSION: These results demonstrate that elevated numbers of cells expressing alpha GM-CSFr can be detected in nonatopic asthma but not in atopic asthma and suggest that this increased expression is predominantly macrophage-associated and may play an important pathophysiologic role in intrinsic asthma.

Adult↗

PubMed1997

Expression of IL-16 in allergen-induced late-phase nasal responses and relation to topical glucocorticosteroid treatment.

Allergen-induced late nasal responses (LNRs) are associated with a cellular infiltrate in which CD4+ cells are prominent. These cells have been shown to be the major cellular source of Th2-type cytokines. Mechanisms responsible for the local accumulation of CD4+ cells in the nasal mucosa after allergen exposure are unclear. IL-16 is a potent chemoattractant for CD4+ cells in vitro and may play a significant role in recruiting CD4+ cells in LNRs. We investigated the expression of IL-16 messenger RNA and immunoreactivity in nasal biopsy specimens from 17 subjects with allergic rhinitis. A biopsy specimen of the nasal inferior turbinate was obtained before and 24 hours after local nasal provocation with grass pollen extract after 6 weeks of treatment with either topical fluticasone propionate (n = 9) or placebo (n = 8) nasal spray twice daily. IL-16 mRNA-positive cells and IL-16-immunoreactive cells were identified in both the epithelium and the subepithelial tissue at baseline. Within the placebo-treated group, the numbers of epithelial and subepithelial IL-16 mRNA-positive cells and IL-16-immunoreactive cells were significantly increased 24 hours after challenge compared with baseline (p < 0.001). Topical glucocorticoid therapy resulted in a decrease in allergen-induced epithelial immunoreactive cells and subepithelial IL-16 mRNA-positive cells. The numbers of CD4+ cells increased after antigen challenge compared with baseline (p < 0.05), and this increase was inhibited by glucocorticoid treatment. There were significant correlations between epithelial and subepithelial IL-16 immunoreactivity and CD4+ cell infiltration after antigen challenge. The upregulation of IL-16 expression in allergic nasal mucosa after antigen challenge may have critical implications in the accumulation of CD4+ cells in response to antigen exposure. Steroid-mediated inhibition of IL-16 may be partly responsible for the decrease in local CD4+ cells after topical glucocorticoid therapy.

Administration, Topical↗

PubMed1997

Inflammation of small airways in asthma.

This study was designed to examine the inflammatory process in the central and peripheral airways of surgically resected lungs from asthmatic and nonasthmatic subjects. Lung specimens were inflated with cryoprotective, rapidly frozen, and systematically sampled. Cryosections prepared from frozen tissue blocks were fixed in acetone/methanol and immunostained with monoclonal antibodies by using the alkaline phosphatase-anti-alkaline phosphatase technique to detect CD3 (T cells), major basic protein (total eosinophils), EG2 (activated eosinophils), anti-tryptase (mast cells), anti-elastase (neutrophils), and CD68 (macrophages). All airways from patients with asthma demonstrated a significant increase in the numbers of T cells and total and activated eosinophils compared with airways from nonasthmatic subjects (p < 0.001). In the patients with asthma, the numbers of activated eosinophils but not T cells were significantly greater in airways with an internal perimeter less than 2 mm compared with those with an internal perimeter greater than 2 mm (p < 0.05). There were also significantly higher numbers of major basic protein-positive eosinophils, when expressed as a fraction of the alveolar wall tissue, in patients with asthma compared with control subjects (p < 0.05). In asthmatic airways with an internal perimeter of more than 2 mm, there was a greater number of activated eosinophils in the tissue between the epithelium and the smooth muscle compared with the tissue between the smooth muscle layer and lung parenchyma (p < 0.05). In contrast, there was a greater number of total eosinophils in the outer airway layer compared with the inner airway layer (p < 0.05). These results show that there is a similar but more severe inflammatory process present in the peripheral compared with the central airways of patients with asthma, which is consistent with the fact that the smaller airways are a major site of obstruction in asthma.

Adult↗

PubMed1997

RANTES in human allergen-induced rhinitis: cellular source and relation to tissue eosinophilia.

Human allergen-induced rhinitis is associated with recruitment and activation of CD4+ T lymphocytes and eosinophils. RANTES is a novel CC chemokine that is a potent chemoattractant for both memory T cells and eosinophils. We therefore investigated RANTES in the nasal mucosa after local allergen provocation. Nasal lavage was performed, and biopsies from the inferior nasal turbinate were taken from 14 atopic, seasonal rhinitic patients and seven normal subjects for as long as 6 h after challenge with a grass pollen extract and after a control (allergen diluent) challenge. In five of seven rhinitics tested, radioimmunoassay of nasal fluid demonstrated increases in RANTES at 2 to 4 h (p < 0.05). Nasal allergen challenge provoked significant increases in RANTES mRNA (p = 0.0015) and protein (p = 0.01) containing cells in the nasal submucosa at 6 h. No changes were observed in normal subjects. Increases in RANTES mRNA+ cells correlated with the associated increases in eosinophils (r = 0.78, p = 0.001). Colocalization studies revealed that the majority of RANTES mRNA+ cells were macrophages (51%) followed by eosinophils (15%), T lymphocytes (11%), and mast cells (3%). Our results demonstrate that allergen-induced rhinitis is associated with release of RANTES and upregulation of RANTES mRNA and protein+ cells, predominantly macrophages, in the nasal mucosa. RANTES synthesis, release, or receptor antagonism may represent a potential target for antiallergy treatment.

Adult↗

PubMed1997

IFN-gamma and IL-12 are increased in active compared with inactive tuberculosis.

Cytokine-mediated immune responses to Mycobacterium tuberculosis infection are important determinants of M. tuberculosis disease development and pathology. However, the distinction between changes in cytokine profile attributable to M. tuberculosis infection and those associated with active pulmonary tuberculosis is unclear. We have compared T cells and their subsets, macrophages, and cytokine messenger RNA (mRNA) profile in the bronchoalveolar lavage (BAL) of patients with active pulmonary tuberculosis with inactive tuberculosis subjects. Ten patients with microbiologically confirmed active pulmonary tuberculosis and 25 subjects with inactive tuberculosis were recruited. Bronchoscopy with BAL was undertaken in all cases and BAL cytospins were examined using the techniques of immunocytochemistry and in situ hybridization. There was a significant increase in the percentage of BAL cells that were CD8+ T cells in active tuberculosis compared with inactive tuberculosis (mean +/- SEM: 7.2 +/- 0.9 versus 2.1 +/- 0.4, p < 0.001), but not CD3+ or CD4+ T cells nor macrophages. There were significant increases in the percentage of BAL cells expressing mRNA for interferon-gamma (IFN-gamma) and interleukin-12 (IL-12) in active versus inactive pulmonary tuberculosis subjects (8.0 +/- 0.6 versus 3.7 +/- 0.4 and 28.4 +/- 2.3 versus 10.2 +/- 1.0, p < 0.001, respectively). There were no significant differences between the active and inactive groups in the number of cells expressing mRNA for IL-2, tumor necrosis factor-alpha (TNF-alpha), IL-4, and IL-5. In conclusion, active pulmonary tuberculosis is associated with increased numbers of CD8+ cells and marked increases in the expression of IL-12 and IFN-gamma mRNA in the BAL, both of which may be useful markers of disease activity.

Bronchoalveolar Lavage Fluid↗

PubMed1997

Expression of IL-12 and IL-13 mRNA in asthma and their modulation in response to steroid therapy.

Interleukin-12 (IL-12) and IL-13 are two recently characterized cytokines which play an important role in the induction of T helper cell type 1 (Th1-) and Th2-like cells, respectively. Using the technique of in situ hybridization, we have investigated the expression of these cytokines in bronchial biopsies from nine allergic asthmatics and nine normal control subjects. To determine the effect of steroid therapy on the expression of IL-12 and IL-13 in asthma, the numbers of cells expressing these cytokine mRNA before and after a 1-wk course of oral prednisone in six steroid-sensitive (SS) and five steroid-resistant (SR) moderately severe asthmatics were also examined. There was an increased number of IL-13, and a decreased number of IL-12 mRNA positive cells in asthmatic subjects compared with normal control subjects (p < 0.001). After steroid treatment, the increase in FEV1 values observed in SS asthmatics was accompanied by a significant decrease in cells expressing IL-13 mRNA (p < 0.05) and an increase in the numbers of cells expressing IL-12 mRNA (p < 0.05). In contrast, steroid therapy in SR asthmatics was not associated with significant changes in IL-12 and IL-13 mRNA expression. Thus, allergic asthma is associated with a downregulation of IL-12 mRNA expression and an upregulation of IL-13 mRNA expression. These results suggest an in vivo role for IL-12 and IL-13 in modulating allergic responses and support the notion that the clinical effects of glucocorticoids are at least partially mediated through the modulation of cytokine production.

Adult↗

PubMed1997

Membrane-bound and soluble alpha IL-5 receptor mRNA in the bronchial mucosa of atopic and nonatopic asthmatics.

Eosinophilic inflammation and interleukin-5 (IL-5) expression are characteristic features of the bronchial mucosa in asthma. We have investigated the differential expression of membrane and soluble isoforms of alpha IL-5 receptor (alpha IL-5Rm and alpha IL-5Rs) mRNA in asthmatics and in normal control subjects and examined the correlation between alpha IL-5Rm and alpha IL-5Rs expression and the FEV1 and airway hyperresponsiveness. Nineteen subjects with stable asthma (atopic = 9; intrinsic = 10) and 22 control subjects (atopic = 12; nonatopic = 10) were recruited. Endobronchial biopsies were obtained and processed for in situ hybridization and double-staining techniques. There was a significant increase in the number of cells per millimeter basement membrane expressing mRNA for total, membrane-bound, and soluble alpha IL-5R in asthmatics when compared with that in nonasthmatic control subjects (p < 0.001); 93% of the cells positive for alpha IL-5R mRNA were EG2+ve eosinophils. There was no significant difference in the expression of alpha IL-5Rm and alpha IL-5Rs between the atopic and nonatopic asthmatics. The expression of alpha IL-5Rm and alpha IL-5Rs was also nonsignificantly different between the atopic and nonatopic control subjects. However, in the asthmatic subjects, the number of positive cells expressing mRNA for alpha IL-5Rm inversely correlated with FEV1(r2 = 0.89, p < 0.001), whereas the expression of alpha IL-5Rs mRNA directly correlated with FEV1 (r2 = 0.52, p < 0.001). There were no significant correlations between alpha IL-5R isoforms and the methacholine PC20. These results suggest that alpha IL-5R upregulation and differential regulation of alternatively spliced alpha IL-5R mRNA transcripts may influence the eosinophil response and the accompanying changes in airflow limitation in both atopic and nonatopic variants of chronic asthma.

Adult↗

PubMed1997

Inducible nitric oxide synthase mRNA and immunoreactivity in the lungs of rats eight hours after antigen challenge.

We have previously shown that inducible nitric oxide (iNO)-synthase immunoreactivity is expressed in bronchial epithelium and increased in asthma which suggests a possible role for NO in airway hyperresponsiveness. We tested the hypothesis that exposure of a sensitized animal to antigen could account for the increased expression of iNO-synthase in the airways. We examined the expression of iNO-synthase mRNA and immunoreactivity in the lungs of ovalbumin (OA) sensitized Brown Norway (BN) rats 8 h after antigen challenge by in situ hybridization and immunocytochemistry. Sensitized and unchallenged or bovine serum albumin (BSA) challenged rats, or unsensitized and OA challenged rats served as controls. With the use of an iNO-synthase probe we found a higher expression of iNO-synthase mRNA in BN rat airways after antigen challenge with OA but not after antigen challenge with BSA or in other controls. Most of the expression was in the epithelium of the airways with few cells positive in the subepithelial inflammatory infiltrate or in lung lavage. Very strong iNO-synthase immunoreactivity was observed in the airway epithelium of sensitized and OA challenged rats. No significant immunoreactivity was observed in the inflammatory infiltrate of the airways or in lung parenchyma. In conclusion, iNO-synthase increases in the airways of sensitized rats after exposure to antigen, the major source being from airway epithelial cells. NO may have a role in the development of the late airway response and bronchial hyperresponsiveness.

Animals↗

PubMed1997

IL-13 mRNA and immunoreactivity in allergen-induced rhinitis: comparison with IL-4 expression and modulation by topical glucocorticoid therapy.

The allergen-induced late nasal response (LNR) is associated with high expression of interleukin-4 (IL-4) and IL-5 messenger RNA (mRNA) in the nasal mucosa, suggesting a role for Th2-type cytokines in the development of the LNR. Moreover, topical corticosteroid-mediated inhibition of the LNR is accompanied by inhibition of IL-4, but not IL-5, mRNA expression, IL-13 shares a number of functions with IL-4, including IgE switching and vascular cell adhesion molecule-1 (VCAM-1) upregulation. We investigated the expression of IL-13 mRNA and immunoreactivity in nasal biopsies from 10 normal subjects and 20 subjects with allergic rhinitis. IL-4 mRNA expression was examined in the same subjects. The allergic rhinitis patients were randomized to receive a 6-wk treatment with either topical fluticasone propionate (n = 10) or placebo (n = 10) nasal spray twice daily. A nasal biopsy was taken before treatment and 24 h after local nasal allergen provocation with a grass-pollen extract. Before treatment, there was no significant difference between the allergic rhinitis patients and controls in the expression of IL-13 mRNA and immunoreactivity. After allergen provocation, we observed a significant increase in IL-13 mRNA-positive and immunoreactive cells at 24 h only in subjects given placebo (P < 0.001). Inhibition of the LNR after corticosteroid treatment was associated with a marked decrease in allergen-induced IL-13 mRNA-positive (P < 0.001) and immunoreactive cells (P < 0.001). In subjects given placebo, 76.9 +/- 5.5% of IL-13 mRNA-positive cells observed after allergen were CD3+, whereas 11.2 +/- 2.7% coexpressed immunoreactivity for mast-cell tryptase. In these subjects, increases in cells expressing IL-13 mRNA were greater than for IL-4 mRNA (P = 0.001), and double in situ hybridization studies revealed that 100% of the IL-4 mRNA-positive cells coexpressed IL-13 mRNA, whereas 66.6 +/- 10.5% of IL-13 mRNA-positive cells coexpressed IL-4 transcripts after allergen challenge. The results of this study suggest that IL-13 expression is a prominent feature of the LNR, and that inhibition of the LNR following steroid therapy may be partly attributable to inhibition of IL-13 expression.

Administration, Intranasal↗

PubMed1997

Increased expression of interleukin-16 in bronchial mucosa of subjects with atopic asthma.

Asthma is characterized by the presence of activated CD4+ cells in the airways. We hypothesized that the newly characterized cytokine interleukin (IL)-16 is involved in the pathogenesis of asthma through its ability to selectively induce CD4+ cell recruitment within the inflamed bronchial wall. We investigated the expression of IL-16 in bronchial biopsies obtained from subjects with mild asthma (n = 10), atopic nonasthmatic individuals (n = 6), and normal control subjects (n = 10). Cryostat sections from 4% paraformaldehyde-fixed fiberoptic bronchial biopsies were immunostained using a specific antibody that recognizes human IL-16. IL-16 mRNA expression was determined by in situ hybridization. IL-16 immunoreactivity and mRNA were demonstrated mainly in bronchial epithelial cells in all subjects. IL-16 immunoreactivity and IL-16 mRNA expression within the epithelium were significantly higher in bronchial biopsies obtained from asthmatic subjects as compared to both atopic nonasthmatic and normal controls (P < 0.001). The numbers of subepithelial IL-16 immunoreactive cells and IL-16 mRNA-positive cells were also greater in the bronchial biopsies obtained from asthmatic subjects as compared to both atopic nonasthmatic and normal controls (P < 0.001). Epithelial expression of IL-16 immunoreactivity and mRNA correlated with the CD4+ cell infiltration (r2 = 0.70, P < 0.001). There were significant associations between epithelial and subepithelial IL-16 immunoreactivity and airway responsiveness to methacholine. This study demonstates that IL-16 is expressed in airway tissues, particularly in the epithelial cells, and that up-regulation of its expression is a feature of allergic asthma. These results suggest an in vivo role for IL-16 in the pathogenesis of asthma, possibly through the recruitment of CD4+ cells, and support the increasing evidence for the participation of epithelial cells in regulating inflammatory responses.

Adult↗

PubMed1997

Eosinophil-associated TGF-beta1 mRNA expression and airways fibrosis in bronchial asthma.

The histopathology of bronchial asthma is associated with structural changes within the airways, including subepithelial fibrosis, as well as chronic eosinophilic inflammation. The mechanisms responsible for this tissue remodeling, and in particular the role of inflammatory cells, remain to be established. Transforming growth factor-beta (TGF-beta) is a potent profibrotic cytokine which may contribute to the thickening of the reticular lamina by the deposition of collagen fibers. To investigate the molecular mechanisms underlying these structural changes, we have investigated the expression of TGF-beta1 mRNA and immunoreactivity within the bronchial mucosa of mild to severe asthmatic individuals and normal control subjects using the techniques of in situ hybridization and immunocytochemistry. As eosinophils are prominent within the asthmatic airway and are known to synthesize pro-inflammatory cytokines, the presence of TGF-beta1 mRNA and immunoreactive protein in eosinophils was also examined. Asthmatic individuals exhibited a greater expression of TGF-beta1 mRNA and immunoreactivity in the airways submucosa than normal control subjects (P < 0.05), and these increases were directly related to the severity of the disorder. The extent of airways fibrosis, as detected histochemically, was also increased in asthmatics compared with normal control subjects (P < 0.005). In asthmatic subjects, the presence of subepithelial fibrosis was associated with the severity of the disease and correlated with the decline in forced expiratory volume in 1 s (r2 = 0.78; P < 0.05). Within the asthmatic airways, EG2-positive eosinophils represented the major source of TGF-beta1 mRNA and immunoreactivity. These results provide evidence that TGF-beta1 may play a role in the fibrotic changes occurring within asthmatic airways and that activated eosinophils are a major source of this cytokine.

Adult↗

PubMed1997

Eotaxin mRNA and protein expression in chronic sinusitis and allergen-induced nasal responses in seasonal allergic rhinitis.

Eotaxin is an eosinophil-specific chemokine associated with the recruitment of eosinophils to the site of allergic inflammation. The aims of this study were to determine the expression of eotaxin in nasal biopsies from allergic and nonallergic individuals with chronic severe sinusitis, and to examine whether the expression of this chemokine is upregulated following allergen challenge in the nasal mucosa of patients with allergic rhinitis. We also undertook to phenotype of inflammatory cells within the submucosa expressing eotaxin mRNA. Nasal turbinate tissue from 16 individuals with allergic or nonallergic chronic sinusitis and 10 normal controls were examined for the presence of eotaxin mRNA and immunoreactivity by in situ hybridization and immunocytochemistry. The numbers of cells expressing eotaxin mRNA were also determined after either allergen or diluent challenge in atopic subjects with a history of allergic rhinitis. There was a constitutive expression of eotaxin-immunoreactivity and the presence of eotaxin mRNA-positive cells in nasal biopsies from normal individuals. Compared with normal controls, the numbers of cells expressing eotaxin mRNA and protein were significantly increased in both allergic and nonallergic sinusitis (P < 0.001). Eotaxin mRNA was expressed by nasal epithelial cells and primarily colocalized to CD68-positive macrophages within the subepithelium. In subjects with allergic rhinitis, allergen challenge markedly increased the numbers of cells expressing eotaxin mRNA and immunoreactivity in the epithelial and subepithelial cell layers (P < 0.05). This could be largely attributed to a local increase in eotaxin production within the nasal tissues. The results of this study demonstrate the constitutive expression of eotaxin and show that the numbers of cells expressing eotaxin mRNA are increased within the epithelial and subepithelial layers of the nasal mucosa in individuals with chronic sinusitis. Furthermore, allergen challenge of the nasal mucosa in atopic subjects results in a local upregulation of eotaxin expression. These data suggest a potential role for this chemokine in the pathogenesis of allergic and nonallergic eosinophilic inflammation characterizing chronic sinusitis and allergic rhinitis.

Adult↗

PubMed1997

Cytokine mRNA gene expression in active and nonactive pulmonary sarcoidosis.

Sarcoidosis is a multisystem granulomatous disease associated with the expansion and activation of CD4+ T-lymphocytes and macrophages. To investigate the immunopathology of active and nonactive pulmonary sarcoidosis, we have examined the expression of cytokine gene transcripts in bronchoalveolar lavage cells from 15 patients with active pulmonary sarcoidosis, eight patients with non-active pulmonary sarcoidosis, and nine normal controls. Using in situ hybridization, the percentage of cells expressing messenger ribonucleic acid (mRNA) for interleukin (IL)-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12 and interferon-gamma (IFN-gamma) were compared in the groups studied. In individuals with active sarcoidosis, there were significantly greater proportions of cells expressing mRNA for IL-2, IL-10, IL-12 and IFN-gamma than in subjects with nonactive disease and normal controls (p < 0.01). There was no significant difference in the percentage of positive cells expressing IL-10 and IL-12 mRNA in the nonactive group compared to the normal controls (p > 0.05). No significant differences in the percentages of IL-3, IL-4 and IL-5 mRNA positive cells were observed between active and nonactive sarcoidosis patients and normal controls (p > 0.05). These results demonstrate that there is a preferential expression of T-helper type 1 cytokines in pulmonary sarcoidosis, and that cytokines related to macrophage activation are the most prominent. In addition, these data implicate an elevated expression of interleukin-2, -10 and -12 and interferon-gamma in active compared to nonactive sarcoidosis.

Adult↗

PubMed1997

Inhaled glucocorticoid therapy of childhood asthma is associated with reduced peripheral blood T cell activation and 'Th2-type' cytokine mRNA expression.

OBJECTIVE: To investigate the role of activated T cells and their cytokine products in the pathogenesis of childhood asthma. METHODS: PBMC were obtained from 17 symptomatic asthmatic children (age 7 to 15 yr) and 7 nonasthmatic controls matched for age and atopic status. Asthmatics were placed in 2 groups with initial prebronchodilator FEV1 <75% (Group I, n = 9) or >/=75% (Group II, n = 8) predicted. Expression of activation markers on peripheral blood T cells (asthmatics), and expression of cytokine mRNA (asthmatics and controls) were measured using flow cytometry and in situ hybridization respectively. Measurements were repeated in the asthmatics 3 to 6 months later following initiation or escalation of inhaled GC therapy for control of symptoms. RESULTS: The more severe (Group I) as compared with the milder (Group II) asthmatics showed evidence of increased peripheral blood T cell activation, with elevated percentages of CD4 cells expressing the activation markers CD25 and HLA-DR, and CD8 cells expressing CD25. Elevated percentages of CD4 cells also expressed CD45RO, consistent with ongoing cellular activation. The asthmatics had higher percentages of PBMC expressing mRNA encoding IL-5, IL-4, GM-CSF and IL-2, but not IFN-gamma, as compared with controls. The percentages of PBMC expressing IL-5 mRNA correlated with disease severity (% predicted FEV1). During follow up, patients in both groups required increased mean daily dosages of inhaled GC. In Group I this was associated with improvements in PEFR, FEV1 and night time wheeze and reduced percentages of CD4/CD25 and CD4/HLA-DR peripheral blood T cells. Reductions in the percentages of CD4/CD25 T cells correlated with improvements in baseline FEV1. Group II patients showed improvement in FEV1 and day time cough and wheeze but no significant changes in PEFR, other symptoms or peripheral blood T cell marker expression. Increased GC therapy of both groups taken together was associated with significant reductions in the percentages of PBMC expressing mRNA encoding IL-5, IL-4 and IL-2 and an increase in those expressing IFN-gamma mRNA. CONCLUSIONS: Compared with controls, children with symptomatic asthma have higher percentages of activated peripheral blood T cells synthesising cytokines believed to regulate bronchial mucosal eosinophilic inflammation. Clinical improvement with increased inhaled GC therapy is associated with reduced T cell activation and cytokine mRNA expression.

Administration, Inhalation↗

PubMed1997

IL-5 and IL-5 receptor in asthma.

Eosinophils, along with mast cells are key cells involved in the innate immune response against parasitic infection whereas the adaptive immune response is largely dependent on lymphocytes. In chronic parasitic disease and in chronic allergic disease, IL-5 is predominantly a T cell derived cytokine which is particularly important for the terminal differentiation, activation and survival of committed eosinophil precursors. The human IL-5 gene is located on chromosome 5 in a gene cluster that contains the evolutionary related IL-4 family of cytokine genes. The human IL-5 receptor complex is a heterodimer consisting of a unique alpha subunit (predominantly expressed on eosinophils) and a beta subunit which is shared between the receptors for IL-3 & GM-CSF (more widely expressed). The alpha subunit is required for ligand-specific binding whereas association with the beta subunit results in increased binding affinity. The alternative splicing of the alpha IL-5R gene which contains 14 exons can yield several alpha-IL-5R isoforms including a membrane-anchored isoform (alpha IL-5Rm) and a soluble isoform (alpha IL-5Rs). Cytokines such as IL-5 produce specific and non-specific cellular responses through specific cell membrane receptor mediated activation of intracellular signal transduction pathways which, to a large part, regulate gene expression. The major intracellular signal transduction mechanism is activation of non-receptor associated tyrosine kinases including JAK and MAP kinases which can then transduce signals via a novel family of transcriptional factors named signal transducers and activators of transcription (STATS). JAK2, STAT1, and STAT5 appear to be particularly important in IL-5 mediated eosinophil responses. Asthma is characterized by episodic airways obstruction, increased bronchial responsiveness, and airway inflammation. Several studies have shown an association between the number of activated T cells and eosinophils in the airways and abnormalities in FEV1, airway reactivity and clinical severity in asthma. It has now been well documented that IL-5 is highly expressed in the bronchial mucosa of atopic and intrinsic asthmatics and that the increased IL-5 mRNA present in airway tissues is predominantly T cell derived. Immunocytochemical staining of bronchial biopsy sections has confirmed that IL-5 mRNA transcripts are translated into protein in asthmatic subjects. Furthermore, the number of activated CD4 + T cells and IL-5 mRNA positive cells are increased in asthmatic airways following antigen challenge and studies that have examined IL-5 expression in asthmatic subjects before and after steroids have shown significantly decreased expression following oral corticosteroid treatment in steroid-sensitive asthma but not in steroid resistant and chronic severe steroid dependent asthma. The link between T cell derived IL-5 and eosinophil activation in asthmatic airways is further strengthened by the demonstration that there is an increased number of alpha IL-5R mRNA positive cells in the bronchial biopsies of atopic and non-atopic asthmatic subjects and that the eosinophil is the predominant site of this increased alpha IL-5R mRNA expression. We have also shown that the subset of activated eosinophils that expressed mRNA for membrane bound alpha IL-5r inversely correlated with FEV1, whereas the subset of activated eosinophils that expressed mRNA for soluble alpha IL-5r directly correlated with FEV1. Hence, not only does this data suggest that the presence of eosinophils expressing alpha IL-5R mRNA contribute towards the pathogenesis of bronchial asthma, but also that the eosinophil phenotype with respect to alpha IL-5R isoform expression is of central importance. Finally, there are several animal, and more recently in vitro lung explant, models of allergen induced eosinophilia, late airway responses (LARS), and bronchial hyperresponsiveness (BHR)--all of which support a link between IL-5 and airway eosinophilia and bronc

Adrenal Cortex Hormones↗

PubMed1997

IL-4 and IL-13 expression in chronic sinusitis: relationship with cellular infiltrate and effect of topical corticosteroid treatment.

OBJECTIVE: Chronic sinusitis with allergy (ACS) and without allergy (NCS) are inflammatory diseases with considerable morbidity. The present study was undertaken to investigate, by in situ hybridization, the expression of IL-13 and IL-4 mRNA in sinus biopsy sections. METHOD: Specimens were obtained from subjects with NCS (n = 12), ACS (n = 13), ACS on steroid therapy (n = 11), and normal controls (n = 11). The composition of the inflammatory infiltrate was also examined in all cases. RESULTS: The number of cells expressing IL-4 and IL-13 transcripts was significantly higher in subjects with ACS compared to normal controls. In contrast, the numbers of IL-13 but not IL-4 mRNA-positive cells were increased in the NCS subjects compared to the normal controls. IL-4 and IL-13 mRNA expression was suppressed in ACS subjects on topical steroid therapy compared to untreated patients. There was no significant difference in the numbers of eosinophils between the ACS subjects treated with steroids and those who were not treated, but the steroid-treated patients demonstrated significantly higher numbers of CD8+ cells in the sinus mucosa. Increased numbers of CD8+ cells were also observed in subjects with NCS compared with ACS subjects and normal controls. CONCLUSIONS: These results demonstrate that increased IL-13 expression is an important feature of allergic and nonallergic patients with chronic sinusitis. Furthermore, our data indicate that IL-13 and IL-4 are under differential regulation in NCS subjects.

Adolescent↗

PubMed1996

Human monocyte chemoattractant protein (MCP)-4 is a novel CC chemokine with activities on monocytes, eosinophils, and basophils induced in allergic and nonallergic inflammation that signals through the CC chemokine receptors (CCR)-2 and -3.

The chemokines are a large family of cytokines that regulate the complex and precise recruitment of immune cells into inflammatory foci. To fully appreciate their role in the pathogenesis of human diseases, the entire spectrum of chemokines, their receptors, their cellular targets, and mechanisms of regulation need to be delineated. Using eotaxin as a probe, we isolated a cDNA for a novel human beta (or CC) chemokine that, based on its biological and structural features, we have named monocyte chemoattractant protein (MCP)-4. Purified recombinant MCP-4 protein was a potent chemoattractant for monocytes and eosinophils and stimulated histamine release from basophils. MCP-4 induced a calcium flux in HEK-293 cells transfected with the monocyte selective MCP-1 receptor (CCR-2B) and the eosinophil selective eotaxin receptor (CCR-3), but not in the more widely expressed CCR-1 or CCR-5. This novel chemokine is expressed in TNF-alpha and IL-1 activated epithelial and endothelial cells in vitro, and in the epithelial mucosa of patients with both Th2-type allergic and Th1-type nonallergic sinusitis. Furthermore, both IFN-gamma and IL-4, products of Th1 and Th2 cells, respectively, synergized with TNF-alpha and IL-1 in inducing MCP-4 mRNA accumulation. These properties of MCP-4 offer a molecular explanation for the observed accumulation of monocytes, eosinophils and basophils in both Th1- and Th2-type immune responses.

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