Biomedical subjects

S Ying

Publications and source records attributed to S Ying.

At least 19 recordsLinked to original sources

PubMed2005

Fel d 1-derived T cell peptide therapy induces recruitment of CD4+ CD25+; CD4+ interferon-gamma+ T helper type 1 cells to sites of allergen-induced late-phase skin reactions in cat-allergic subjects.

BACKGROUND: Specific immunotherapy with whole allergen extracts is associated with local accumulation of IFN-gamma+ and CD25+ cells indicating recruitment of activated T-helper type 1 (Th1) and/or T regulatory cells. We have studied allergen-induced, late-phase skin biopsies before and after T cell peptide therapy for evidence of alterations in the pattern of local recruitment of Th1, T-helper type 2 (Th2) and T regulatory cells. OBJECTIVE: To evaluate the effect of T cell peptide therapy on the allergen-induced cutaneous late-phase reaction. METHODS: Increasing doses of synthetic Fel d 1-derived peptides were administered (by intradermal injection) to eight cat-allergic asthmatics at 14-day intervals. Twenty-four-hour skin biopsies were taken from whole cat allergen- and diluent-injected sites, before and after treatment and studied by immunohistochemistry and in situ hybridization. RESULTS: Fel-d 1 peptides decreased airway hyper-responsiveness (P = 0.02) and inhibited the late-phase cutaneous reaction (LPCR) to whole cat allergen (P = 0.03). This was associated with significant increases (post- vs. pre-treatment) in the number of cutaneous CD4+/IFN-gamma+ (P = 0.03) and CD4+/CD25+ cells (P = 0.04), but not in CD4+/IL-10+ or CD4+/CTLA-4+ cells. CONCLUSIONS: Treatment with allergen-derived T cell peptides results in allergen-dependent recruitment to the skin of Th1, rather than T regulatory cells, to cutaneous late-phase reaction sites.

Animals↗

PubMed2004

Interactions between eotaxin, histamine and mast cells in early microvascular events associated with eosinophil recruitment to the site of allergic skin reactions in humans.

BACKGROUND: The mechanism whereby allergen induces eotaxin expression at the site of allergic inflammation is incompletely understood. Structural cells, including endothelial cells, are a major source of eotaxin. OBJECTIVE: We have investigated, in vivo and in vitro, the relationship between mast cell activation and the expression of eotaxin (eotaxin 1) by endothelial cells. METHODS: The effects of intradermal allergen challenge and histamine injection on eotaxin mRNA and protein generation were studied in atopic subjects using immunofluorescence, immunohistochemistry and in situ hybridization. Histamine-induced expression of eotaxin mRNA and protein by endothelial cells was also measured, as was histamine-induced eosinophil adhesion to cultured endothelial cells. RESULTS: A rapid increase in degranulating cutaneous mast cells, together with a concomitant increase in eosinophils, was observed 60 min after allergen challenge. This was accompanied by the appearance of immunoreactive eotaxin that peaked at 1 h around blood vessels and at 3 h within the tissue. Intradermal histamine injection produced an increase in the number of eotaxin+ cells in the tissues, which was maximal at the 3-h time-point. In vitro, endothelial cells produced eotaxin mRNA and protein product in a dose- and time-dependent fashion following incubation with histamine, an effect that was blocked by levocetirizine. Pre-incubation of endothelial cells with histamine also induced a significant increase in eosinophil adherence, an effect that was inhibited with an anti-eotaxin blocking monoclonal antibody. CONCLUSION: The antigen-induced expression of eotaxin by endothelial cells and the adherence and subsequent migration of eosinophils from the microvasculature to the tissues are rapid events partially under the control of histamine released from degranulating mast cells.

Adult↗

PubMed2003

Nodulus infarction mimicking acute peripheral vestibulopathy.

The authors report two patients with cerebellar infarctions in the territory of the medial branch of the posterior inferior cerebellar artery who had vertigo, spontaneous ipsilesional nystagmus, and contralesional truncal lateropulsion. Although one of the two patients had slight dysmetria, overall signs closely mimicked those of acute peripheral vestibulopathy. The authors suggest that interruption of nodulouvular inhibitory projections to vestibular nuclei may account for the vestibular signs.

Aged↗

PubMed2003

Cyclosporin A, apoptosis of BAL T-cells and expression of Bcl-2 in asthmatics.

The late asthmatic reaction is characterised by elevated numbers of interleukin-4/interleukin-5/CD4-positive T-helper cells type 2 in bronchoalveolar lavage fluid (BALF). Cyclosporin A (CsA) is known to inhibit T-cell proliferation, induce apoptosis of CD4-positive T-cells and downregulate cytokine gene expression. It was assessed whether CsA-induced inhibition of the late asthmatic reaction was associated with apoptosis of BALF T-lymphocytes and other cell types, as well as expression of the antiapoptotic protein B-cell leukaemia/lymphoma 2 gene product (Bcl-2). BALF cells were obtained from asthmatics at baseline and 24 h after allergen-inhalation challenge following prior administration of CsA (n=13) or placebo (n=11). The number of apoptotic CD3-positive T-lymphocytes increased in the CsA but not the placebo group. The numbers of Bcl-2-positive cells were significantly reduced in the CsA but not the placebo group. The majority of Bcl-2-positive cells were CD3-positive T-lymphocytes. The beneficial effect of cyclosporin A in asthma may be related to its inhibitory effect on the late asthmatic reaction via induction of T-cell apoptosis and decreased B-cell leukaemia/lymphoma 2 gene product levels.

Apoptosis↗

PubMed2002

Elevated expression of interleukin-9 mRNA in the bronchial mucosa of atopic asthmatics and allergen-induced cutaneous late-phase reaction: relationships to eosinophils, mast cells and T lymphocytes.

BACKGROUND: Interleukin-9 is a T cell-derived Th2-type cytokine that has been linked to airway hyper-responsiveness, mucus hypersecretion and mast cell infiltration in animal models. We recently demonstrated the potential for IL-9 to act in human eosinophil development and survival. OBJECTIVES: The aims of this study were: (i) to compare IL-9 mRNA expression in bronchial biopsies between atopic asthmatics and normal controls, (ii) to investigate kinetic expression of IL-9 mRNA in skin biopsies after allergen challenge; and (iii) to relate IL-9 expression to infiltration of eosinophils, mast cell and T lymphocytes in local tissue. METHODS: Bronchial biopsies were obtained from atopic asthmatics (n = 12) and normal non-asthmatics (n = 12) at baseline. Skin biopsies were obtained from atopic subjects (n = 11) at 1, 3, 6, 24, 48 and 72 h after allergen challenge. Diluent challenge sites at 24 h were used as controls. IL-9 mRNA was identified using the technique of in situ hybridization. The numbers of eosinophils, mast cells and T cells were evaluated by immunohistochemistry. RESULTS: The numbers of IL-9 mRNA(+) cells present in the bronchial mucosa were significantly greater in atopic asthmatics than those in normal controls (P = 0.003). The numbers of eosinophils, but not mast cells, were also significantly higher in asthmatics (P < 0.005). The numbers of IL-9 mRNA(+) cells present in the airway of asthmatics significantly correlated with the numbers of eosinophils (r = 0.623, P = 0.03), but not mast cells or T cells. Compared with diluent challenge, the numbers of IL-9 mRNA(+) cells were significantly elevated at all allergen-challenged sites in the skin, with maximal signals at 48 h (P < 0.005). At 72 h, the numbers of IL-9 mRNA(+) cells significantly correlated with the numbers of eosinophils (r = 0.707, P = 0.015). CONCLUSION: Elevated expression of IL-9 in allergic inflammation may contribute to local eosinophil infiltration and survival in asthma and other allergic atopic diseases.

Adult↗

PubMed2002

Chronic eosinophilic leukaemia presenting with erythroderma, mild eosinophilia and hyper-IgE: clinical, immunological and cytogenetic features and therapeutic approach. A case report.

A 23-year-old, white male metallurgist presented with pruritic erythematous maculo-papules over the trunk and upper limbs and 6 months later developed erythroderma, eosinophilia and multi-organ dysfunction. A diagnosis of chronic eosinophilic leukaemia was made on the basis of myeloproliferative involvement of both peripheral blood and bone marrow, associated with eosinophilic differentiation and a t(5;12)(q33;p13) translocation. The initial therapeutic approach was interferon alfa-2b plus cytosine arabinoside, for 13 months, followed by hydroxyurea plus vincristine. There was improvement of skin lesions, disappearance of eosinophilia and decrease of serum immunoglobulin E, towards normal values.

Adult↗

PubMed2001

Interleukin-10 levels increase in cutaneous biopsies of patients undergoing wasp venom immunotherapy.

We have studied the influence of wasp venom immunotherapy (VIT) on cellular recruitment and cytokine mRNA expression during allergen-induced cutaneous late-phase responses (LPR). Nine subjects with a history of wasp sting anaphylaxis, and specific IgE in their sera underwent wasp VIT. Skin biopsies were taken 24 h after intradermal diluent and allergen before and after 3 months VIT. Pre-immunotherapy, there were significant allergen-induced increases in EG2(+) eosinophils, elastase(+) neutrophils, CD68(+) macrophages and IL-10 protein(+) cells, and increased expression of mRNA for IL-4, IL-13, IFN-gamma, IL-12, IL-10, TGF-beta, RANTES and eotaxin. When these allergen-induced changes in cytokine mRNA and cellular profiles were compared with those obtained after 3 months VIT there was a significant reduction in IL-4 mRNA (p=0.012) and increase in IL-10 protein(+) cells (p=0.004) with a trend to an increase in IL-10 mRNA (p=0.054). There were also significant reductions in eosinophils (p<0.004) and the size of the cutaneous LPR (p<0.01) but no change in mRNA to IFN-gamma, IL-13 or IL-12. Therefore, VIT is associated with a significant increase in cells positive for IL-10 protein but not IL-12 or IFN-gamma. These results suggest that induction of IL-10 may be important in VIT and occur independently of the switch to a Th1 phenotype. IL-10 generation may down-regulate IL-4 expression and eosinophil recruitment.

Adult↗

PubMed2001

Toxic epidermal necrolysis: 10 years experience of a burns centre in Hong Kong.

Toxic epidermal necrolysis syndrome is characterized by extensive skin rash with blisters and exfoliation similar to that of major burns. Current evidence suggests that toxic epidermal necrolysis syndrome is most likely due to cell-mediated immune response triggered by certain drugs. Recognition of the clinical situation which is similar to major burn has resulted in general agreement that these patients are best treated in a burns unit, where critical support and meticulous wound care can be carried out by experienced personnel. This represents a major step forward in the management of this condition. The 10 year experience of managing seven patients with severe toxic epidermal necrolysis in a tertiary burns centre in Hong Kong is presented and the controversies over classification and management of the disease are also discussed.

Adolescent↗

PubMed2001

Macrophage inflammatory protein-1alpha and C-C chemokine receptor-1 in allergen-induced skin late-phase reactions: relationship to macrophages, neutrophils, basophils, eosinophils and T lymphocytes.

BACKGROUND: Macrophage inflammatory protein (MIP)-1alpha binds to C-C chemokine receptor (CCR)-1 with high affinity. CCR-1 is expressed on neutrophils, eosinophils, monocytes, T lymphocytes and basophils; cells characteristic of atopic allergic inflammation. In vitro, MIP-1alpha is chemotactic for monocytes, T cells and basophils and is also a potent histamine-releasing factor for basophils and mast cells. Although increased levels of MIP-1alpha were shown in atopic allergic disorders, the kinetics of expression of these CC chemokines in vivo is largely unknown. OBJECTIVE: To investigate the kinetics of expression of MIP-1alpha and receptor CCR-1 and the relationships between the expression and infiltration of inflammatory cells in allergen-induced cutaneous late-phase reactions in atopic subjects. METHODS: Cryostat sections, obtained from skin biopsies from 10 human atopic subjects at 6, 24, 48, 72 h and 7 days after allergen challenge, were processed for immunohistochemistry and in situ hybridization using 35S-labelled riboprobes. RESULTS: The peak expression of allergen-induced mRNA for MIP-1alpha and CCR-1 was 6 h. This was maintained at 24 h, and gradually returned to base line at 7 days. At 6 h, the number of cells expressing MIP-1alpha mRNA significantly correlated with elastase+ neutrophils and BB-1+ basophils. At 24 h, the MIP-1alpha mRNA+ cells significantly correlated with CD68+ macrophages. There were significant inverse correlations between the numbers of MIP-1alpha mRNA cells and the numbers of Tryptase+ mast cells at 6 and 24 h after allergen challenge. CONCLUSION: Allergen-induced cutaneous late-phase reactions in humans were associated with increased expression of MIP-1alpha and CCR-1. This may be relevant to the infiltration of neutrophils, eosinophils, basophils and macrophages.

Basophils↗

PubMed2001

Local expression of epsilon germline gene transcripts and RNA for the epsilon heavy chain of IgE in the bronchial mucosa in atopic and nonatopic asthma.

BACKGROUND: The demonstration of epsilon germline gene (Cepsilon) transcripts and mature mRNA for the epsilon heavy chain gene (Iepsilon) in the nasal mucosa suggested that IgE synthesis may occur in allergic rhinitis. OBJECTIVE: In view of our previous demonstration of increases in IL-4 mRNA(+) cells in asthmatic subjects, we assessed whether local IgE synthesis may also be a feature of bronchial asthma. METHODS: Fiberoptic bronchoscopic mucosa biopsy specimens were obtained from 9 atopic asthmatic subjects and 10 nonatopic normal (intrinsic) control subjects. To control for atopy, we also studied 9 nonatopic asthmatic subjects and 10 atopic nonasthmatic control subjects. Tissue was processed for immunohistochemistry for B cells (CD20) and in situ hybridization for Iepsilon and Cepsilon RNA(+) cells and IL-4 mRNA(+) cells. RESULTS: B-cell numbers in the bronchial mucosa were similar for asthmatic subjects compared with control subjects, whereas significantly higher numbers of Iepsilon RNA(+) (P =.02 and P =.04, respectively), Cepsilon RNA(+) (P =.01 and P =.03, respectively), and IL-4 mRNA(+) (P =.001 and P =.001, respectively) cells were observed in atopic asthmatic subjects and nonatopic asthmatic subjects, respectively, but not in atopic control subjects compared with nonatopic control subjects. In asthmatic subjects there were significant correlations between Iepsilon RNA(+) cells (r = 0.54, P =.02) and Cepsilon RNA(+) cells (r = 0.48, P =.05) when compared with the number of IL-4 mRNA(+) cells. CONCLUSION: Increases in Iepsilon and Cepsilon RNA(+) cells, but not B-cell numbers, in the bronchial mucosa provide evidence for local IgE synthesis in both atopic and nonatopic asthma. These changes appear to relate to asthma rather than atopy per se and, at least in part, may be under the regulation of IL-4.

Adult↗

PubMed2001

Late asthmatic reactions provoked by intradermal injection of T-cell peptide epitopes are not associated with bronchial mucosal infiltration of eosinophils or T(H)2-type cells or with elevated concentrations of histamine or eicosanoids in bronchoalveolar fluid.

BACKGROUND: Isolated late asthmatic reactions can be provoked by intradermal challenge of allergen-derived T-cell peptide epitopes. OBJECTIVE: The purpose of this study was to determine whether the isolated LAR is associated with the local accumulation of inflammatory cells, the expression of T(H)2 cytokines, and the production of pharmacologic mediators. METHODS: A randomized, placebo-controlled, crossover study design was used. The investigation involved bronchial and skin biopsies and bronchoalveolar lavage (BAL) fluids from 8 cat-allergic subjects who developed significant late asthmatic reactions 6 hours after intradermal injection of Fel d 1 chain 1-derived peptides (FC1Ps). RESULTS: Immunostaining of bronchial biopsy specimens showed no changes in the numbers of eosinophils, neutrophils, basophils, mast cells, CD3(+), CD4(+) or CD8(+) T cells, CD25(+) cells or macrophages, or cells mRNA(+) for IL-4, IL-5, or IL-13 when the FC1P day was compared with the diluent control day. There were also no significant differences in eosinophil numbers, either in BAL fluids or in peripheral blood after FC1P challenge. Furthermore, there were no significant alterations in the concentrations of histamine, histamine-releasing factors, or eicosanoids (LTC(4)/D(4)/E(4), PGD(2), PGE(2), TXB(2), PGF(2alpha)) in BAL fluids. FC1Ps induced a significant (P <.05) elevation in CD8(+) cells in the skin and an unexpected decrease in IL-5 in BAL fluids (P =.043). CONCLUSION: Part of the asthma process might involve T cell-dependent airway narrowing with no requirement for IgE, mast cells, or infiltrating inflammatory cells.

Adult↗

PubMed2001

Synthesis of a nitrogen analogue of salacinol and its alpha-glucosidase inhibitory activity.

A nitrogen analogue 4 of the naturally occurring sulfonium ion salacinol (1), a potent alpha-glucosidase inhibitor isolated from the Ayruvedic medicine Salacia reticulata, was synthesized and its inhibitory activity against alpha-glucosidase tested. Substitution of the sulfur atom in 1 with a nitrogen reduced the activity considerably. The solid-state stereostructure of the related compound (5) was determined on the basis of single crystal X-ray measurement.

Animals↗

PubMed2000

Regulation of hemoglobin synthesis and proliferation of differentiating erythroid cells by heme-regulated eIF-2alpha kinase.

Protein synthesis in reticulocytes depends on the availability of heme. In heme deficiency, inhibition of protein synthesis correlates with the activation of heme-regulated eIF-2alpha kinase (HRI), which blocks the initiation of protein synthesis by phosphorylating eIF-2alpha. HRI is a hemoprotein with 2 distinct heme-binding domains. Heme negatively regulates HRI activity by binding directly to HRI. To further study the physiological function of HRI, the wild-type (Wt) HRI and dominant-negative inactive mutants of HRI were expressed by retrovirus-mediated transfer in both non-erythroid NIH 3T3 and mouse erythroleukemic (MEL) cells. Expression of Wt HRI in 3T3 cells resulted in the inhibition of protein synthesis, a loss of proliferation, and eventually cell death. Expression of the inactive HRI mutants had no apparent effect on the growth characteristics or morphology of NIH 3T3 cells. In contrast, expression of 3 dominant-negative inactive mutants of HRI in MEL cells resulted in increased hemoglobin production and increased proliferative capacity of these cells upon dimethyl-sulfoxide induction of erythroid differentiation. These results directly demonstrate the importance of HRI in the regulation of protein synthesis in immature erythroid cells and suggest a role of HRI in the regulation of the numbers of matured erythroid cells.

3T3 Cells↗

PubMed2000

Retinal degeneration in cone photoreceptor cell-ablated transgenic mice.

PURPOSE: To examine the effect of loss of cone photoreceptor cells on retinal degeneration. METHODS: We previously identified a cone photoreceptor cell-specific promoter of human cone transducin a-subunit (GNAT2) gene. In this report, a minigene, Trc-Tox176, that contains the GNAT2 promoter, an attenuated diphtheria toxin A-chain gene, and an enhancer element from human interphotoreceptor retinoid-binding protein (IRBP) was used to generate coneless transgenic mice. Transgenic mice were identified by PCR and the copy number of the transgene was determined by Southern hybridization, and examined by histology. RESULTS: The results of immunostaining with anti-mouse GNAT2 antibodies and reverse transcription-PCR (RT-PCR) analysis with mRNA from the retinas of transgenic mice showed that cone photoreceptor cells were ablated in one of four transgenic mouse lines. The ablation of cone cells began at postnatal day 8, at the same time as the expression of endogenous GNAT2. An age-related rod degeneration was also found in this cone-ablated mouse line, beginning at postnatal day 9, proceeding from the central retina to the peripheral retina. CONCLUSIONS: Cone photoreceptor cells may play an important role in the survival of rod photoreceptor cells during mouse retina development.

Animals↗

PubMed2000

Blood eosinophils from atopic donors express messenger RNA for the alpha, beta, and gamma subunits of the high-affinity IgE receptor (Fc epsilon RI) and intracellular, but not cell surface, alpha subunit protein.

BACKGROUND: Blood eosinophils from hypereosinophilic donors were previously reported to possess the functional high-affinity IgE receptor (Fc epsilon RI), so providing a potential mechanism to account for eosinophil degranulation in atopic allergic disease. Furthermore, tissue eosinophils from allergic tissue reactions were shown to be mRNA(+) for the alpha, beta, and gamma subunits of Fc epsilon RI and gave positive immunostaining with an anti-Fc epsilon RI-alpha antibody. Recent studies, however, revealed negative surface staining on peripheral blood eosinophils, but intracellular Fc epsilon RI-alpha protein was identified by Western blot analysis. OBJECTIVE: Our purpose was to examine on peripheral blood eosinophils from atopic subjects (1) surface expression and mRNA for Fc epsilon RI-alpha, (2) up-regulation of Fc epsilon RI-alpha by allergy-associated tissue factors, and (3) Fc epsilon RI-alpha-dependent release of eosinophil peroxidase (EPO). METHODS: We measured (1) Fc epsilon RI mRNA expression by in situ hybridization, (2) Fc epsilon RI-alpha by flow cytometry and immunocytochemistry (with use of nonpermeabilized and permeabilized cells), and (3) Fc epsilon RI-alpha-dependent release of EPO. RESULTS: Eosinophils from atopic donors had negligible surface expression of Fc epsilon RI-alpha, which was not enhanced by culture with IgE, IL-3, IL-4, IL-5, GM-CSF, or fibronectin or coculture with fibroblasts. Permeabilization, however, revealed appreciable intracellular staining for Fc epsilon RI-alpha. The majority of eosinophils were mRNA(+) for the alpha, beta, and gamma subunits of Fc epsilon RI. Small but significant (P =.03) increases in alpha chain mRNA expression were observed after coculture of eosinophils with fibroblasts but not with IgE, IL-4, or fibronectin. Cross-linking of Fc epsilon RI on the surface of eosinophils from atopic donors did not lead to detectable EPO release. CONCLUSION: Human blood eosinophils express negligible, nonfunctional membrane Fc epsilon RI-alpha but have intracellular Fc epsilon RI-alpha protein and mRNA expression for the alpha, beta, and gamma subunits.

Cell Membrane↗

PubMed2000

Basophils, eosinophils, and mast cells in atopic and nonatopic asthma and in late-phase allergic reactions in the lung and skin.

BACKGROUND: Previous studies used indirect methods to identify basophils in the bronchi in asthma, and the numbers were not compared with eosinophils and mast cells. Furthermore, differences in basophil numbers between atopic and nonatopic asthma at baseline and between late-phase skin and asthmatic reactions have not been previously documented. OBJECTIVE: The basophil granule-specific mAb BB1 was used to identify basophils in (1) bronchial biopsy specimens from atopic asthmatic subjects and nonatopic asthmatic subjects and control subjects, (2) biopsy specimens from atopic asthmatic subjects before and after inhalational allergen challenge, and (3) late-phase skin reactions. Basophil numbers were compared with EG2(+) eosinophils and tryptase(+) mast cells. METHODS: Cells were enumerated in bronchial and skin biopsy specimens by means of immunohistochemistry with the alkaline phosphatase-antialkaline phosphatase method. RESULTS: There were elevated numbers of basophils in baseline biopsy specimens in atopic asthmatic subjects compared with atopic control subjects or normal control subjects, although eosinophils and mast cells were 10-fold higher. There was an intermediate number of basophils in nonatopic asthmatic subjects. Basophils increased after allergen inhalation, but again basophils were less than 10% of eosinophils. In contrast, basophils in cutaneous late-phase reactions were approximately 40% of infiltrating eosinophils. The peak of basophil accumulation was at 24 hours, whereas maximal eosinophil infiltration occurred at 6 hours. One third of cutaneous basophils had morphologic appearances suggestive of degranulation. CONCLUSION: Numerous basophils infiltrated cutaneous late-phase reactions in atopic subjects. However, this cell was not prominent in bronchial biopsy specimens of asthmatic subjects, either at baseline or after allergen challenge.

Adult↗

PubMed2000

Expression of eotaxin in induced sputum of atopic and nonatopic asthmatics.

BACKGROUND: The chemokine eotaxin has been implicated in airway eosinophilia in atopic asthma. We have compared airway eosinophils and eotaxin expression in induced sputum from well-matched atopic and nonatopic asthmatics. METHODS: Eosinophil numbers, eosinophil cationic protein (ECP), and the expression of eotaxin were examined in induced sputum from atopic asthmatics (AA = 11), nonatopic asthmatics (NAA = 11), and atopic (AC = 12) and normal (NC = 10) controls. Slides were prepared for differential cell counts by Romanowsky stain, and ECP levels were measured by RIA. Eotaxin expression was detected by in situ hybridization, with 35S-labelled riboprobes and immunocytochemistry. RESULTS: The numbers of eosinophils and ECP concentration were increased in the sputum of AA and NAA compared with AC and NC (P < 0.05). The numbers of eotaxin mRNA+ and immunoreactive cells were increased in NAA, but not AA, when compared with controls (P < 0.05). Eotaxin immunoreactive cells in NAA were significantly higher than in AA (P < 0.05). Eotaxin was expressed predominantly by macrophages, eosinophils, and epithelial cells. In NAA, but not AA, the numbers of eotaxin mRNA+ cells were correlated with histamine PC20 (r = -0.81, P < 0.01) and eosinophil numbers in sputum (r = 0.7, P < 0.05). CONCLUSIONS: Eotaxin production by macrophages, eosinophils, and epithelial cells may play a more pronounced role in airway eosinophilia in nonatopic than in atopic asthma.

Adult↗

PubMed2000

Macrophage subpopulations and macrophage-derived cytokines in sputum of atopic and nonatopic asthmatic subjects and atopic and normal control subjects.

BACKGROUND: Previous studies have shown a prominent macrophage signal in the bronchial mucosa from nonatopic (intrinsic) compared with atopic (extrinsic) asthmatic subjects. This observation might have represented an expansion of a proinflammatory macrophage population or a homeostatic mechanism to decrease T(H)2-type inflammation. OBJECTIVE: The aim of the study was to investigate the numbers of macrophages and macrophage subpopulations and the expression of IL-10 and IL-12 in sputum from asthmatic and control subjects. METHODS: Eight atopic asthmatic (AA) subjects, 10 nonatopic asthmatic (NAA) subjects, 6 atopic control (AC) subjects, and 7 normal control (NC) subjects underwent sputum induction. Macrophages were enumerated by using Romanowsky stain and immunocytochemistry (CD68). RFD1 (interdigitating cell marker) and RFD7 (mature phagocyte marker) mAbs were used for immunocytochemical phenotyping, whereas IL-10 and IL-12 messenger (m)RNA was examined with in situ hybridization by using (35)S-labeled riboprobes. The phenotype of cells expressing IL-10 or IL-12 mRNA was examined by simultaneous in situ hybridization and immunostaining. RESULTS: No differences in the numbers of CD68(+) macrophages and RFD1(+), RFD7(+), and RFD1(+)/RFD7(+) subpopulations were found between AA, NAA, AC, and NC subjects. However, the numbers of IL-10 and IL-12 mRNA(+) cells were increased in AA subjects compared with NAA, AC, and NC subjects (P <.05). No other differences were found among the groups. Most of the IL-10 and IL-12 mRNA(+) cells in sputum from asthmatic subjects were macrophages (>80%), with less than 10% of mRNA colocalizing to epithelial cells. CONCLUSIONS: Sputum macrophage numbers, unlike tissue macrophages, as previously reported, were not elevated in NAA subjects. Increased IL-10 and IL-12 expression in atopic asthma may indicate the existence of a homeostatic mechanism to decrease lung inflammation. The lack of such cytokines in intrinsic asthma may predispose to bronchial inflammation in these subjects.

Asthma↗