Contact activation via ICAM-1 induces changes in airway epithelial permeability in vitro

The role of ICAM-1 in contact activation of the bronchial epithelial cells is elucidated. Direct contact between epithelial cells and leukocytes is required to change transepithelial electrical resistance (TER) of the epithelium. Migration of human neutrophils across the layers of cultured human airway epithelial cells (Calu-3) or primary cow tracheal epithelial cells was induced by an fMLP gradient. Migrating neutrophils decreased TER and increased permeability to albumin. Monoclonal antibodies to ICAM-1 reduced neutrophil migration, thus reducing the changes in TER and changes in the epithelial permeability to albumin. By confocal microscopy, ERK1/2 was found to be locally activated in the epithelial cells at the sites of migration and cross-linking of ICAM-1. Blockade of ERK1/2 by PD98059 decreased the changes in TER which were induced by ICAM-1 cross-linking. Contact activation of the bronchial epithelial cells, involving ICAM-1 via local activation of ERK1/2, is an important mechanism of alteration of the bronchial epithelial permeability.     

In vitro regulation of beta1 and beta3 integrin subunits in endometrial epithelial cells from normal endometrium

OBJECTIVE: To evaluate the effect of prostaglandin E2 (PGE2) and interleukin-1beta (IL-1beta) on integrin expression. DESIGN Cultures of endometrial epithelial cells from normal endometrium. SETTING: All endometrial specimens were obtained from the Obstetrics and gynecology Department of the Catholic University, Rome, Italy. PATIENTS: Four patients were normal menstrual cycles undergoing operative laparoscopy for non-endometrial problems. INTERVENTION: Endometrial samples were collected by uterine courettings. MAIN OUTCOME MEASURE: Immunocytochemistry for beta1 and beta3 integrin subunits. RESULTS: PGE2 clearly enhances both beta1 and beta3 integrin subunit expression. IL-1beta seem to slightly increase only beta3 subunit expression. CONCLUSIONS: In light of the critical role played by eicosanoids in endometrial differentiation, we suggest that PGE2 is also involved in local paracrine regulation of integrin expression.     

Topical ocular levocabastine reduces ICAM-1 expression on epithelial cells both in vivo and in vitro

Background Levocabastine is a selective topical H₁ antagonist, effective in the treatment of seasonal allergic rhinitis and conjunctivitis. Objective We evaluated the possible effects of levocabastine eye drops on early (EPR) and late phase (LPR) inflammatory changes induced by allergen-specific conjunctival challenge (ASCC). We focused our attention on the possible effect of levocubastine on expression of the intracellular adhesion molecule-1 (ICAM-1) on epithelial cells. Such a phenomenon is likely to play an important role in allergic inflammation. Methods The study was a double-blind, placebo-controlled, randomized trial, performed in cross-over, outside the pollen season. Ten out-patients suffcring from allergic rhinoconjunctivitis due to Parietaria Judaica (wall parietary) were enrolled. Patients randomly received levocabastine eye drops (0.5 mg/mL) or placebo eyedrops, one drop in the left eye (right eye as control), 30 min before ASCC. Clinical evaluation (hyperaemia, burning-itching, lacrimation and eyelid swelling) and cytological assessment (number of neutrophils, eosinophils and lymphocytes, and ICAM-1 expression on conjunctival epithelium) were evaluated at baseline, 30min and 6h after ASCC. In parallel, we evaluated the in vitro effect of levocabastine at concentrations ranging from 2 × 10^?9 M to 2 × 10^?5M on ICAM-l expression and shedding by a continuously cultured differentiated epithelial cell line (WK). Results Levocabastine reduced symptom scores during EPR (15min and 30min, P < 0.002), inflammatory cell infiltration duritig FPR (P < 0.002 for neutrophils, eosinophils and lymphocytes) and ICAM-1 expression on epithelium both during EPR (P < 0.002) and LPR (P < 0.02). LPR symptom scores and inflammatory cell infiltration were only slightly modified by levocabastine treatment. In vitro levocabastine at 2 ± 10^?5 M concentration was able to down-regulate basal ICAM-1 expression, although it exerted no effect on ICAM-1 expression by interferon-γ (IFNγ)-stimulated WK cells and on soluble ICAM-1 release by epithelium. Conclusion Levocabastine exerts anti-allcrgJc activity, in that it reduces in vivo inflammatory cell infiltration due to ASCC, and also adhesion molecule expression on conjunctival epithelium. The latter phenomenon may be due, at least in part, to a direct effect of levocabastine on epithelial cells.     

Contact Activation via ICAM-1 Induces Changes in Airway Epithelial Permeability in vitro

The role of ICAM-1 in contact activation of the bronchial epithelial cells is elucidated. Direct contact between epithelial cells and leukocytes is required to change transepithelial electrical resistance (TER) of the epithelium. Migration of human neutrophils across the layers of cultured human airway epithelial cells (Calu-3) or primary cow tracheal epithelial cells was induced by an fMLP gradient. Migrating neutrophils decreased TER and increased permeability to albumin. Monoclonal antibodies to ICAM-1 reduced neutrophil migration, thus reducing the changes in TER and changes in the epithelial permeability to albumin. By confocal microscopy, ERK1/2 was found to be locally activated in the epithelial cells at the sites of migration and cross-linking of ICAM-1. Blockade of ERK1/2 by PD98059 decreased the changes in TER which were induced by ICAM-1 cross-linking. Contact activation of the bronchial epithelial cells, involving ICAM-1 via local activation of ERK1/2, is an important mechanism of alteration of the bronchial epithelial permeability.     

Altered intracellular expression of the chemokines MIP-1alpha,MIP-1beta and IL-8 by peripheral blood CD4+ and CD8+ T cells in mild allergic asthma

BACKGROUND: The ability of chemokines to regulate Th1 and Th2 responses suggests a role in the pathogenesis of atopic disorders such as allergic asthma where Th2 response dominance has been observed. Although the impact of allergic asthma on local chemokine production in the lung has been the subject of investigation, little is know about the influence of disease progression on peripheral chemokine production. We now report use of whole blood culture and flow cytometry to assess the influence of mild allergic asthma on peripheral T-cell chemokine expression. METHODS: Study participants included patients with mild allergic asthma (n = 7) and nonasthmatic controls (n = 7). Following in vitro stimulation of peripheral venous blood with phorbol 12-myristate acetate (PMA) and ionomycin, flow cytometry was used to estimate the percentage of CD4+ and CD8+ T cells producing a number of chemokines, including macrophage inflammatory proteins MIP-1alpha and MIP-1beta, RANTES (regulated on activation, T-cell expressed and secreted), monocytic chemotactic protein-1 (MCP)-1, and interleukin (IL)-8, or the cytokines interferon (IFN)-gamma and IL-4. Serum levels of MIP-1alpha, MIP-1beta, RANTES, MCP-1, IL-8, IFN-gamma and IL-4 were also assessed by quantitative ELISA. RESULTS: Intracellular expression of MIP-1beta by CD4+ and CD8+ T cells from allergic asthmatics was significantly reduced in comparison to that observed for nonasthmatics (median = 2.29% (1.75-3.50) vs 4.57% (3.38-6.64), P = 0.05; 14.20% (13.18-17.88) vs 44.10% (30.38-48.70), P = 0.01). Similarly, intracellular expression of MIP-1alpha by CD8+ T cells from allergic asthmatics was also significantly lower (3.67% (1.17-5.42) vs 17.10% (4.97-20.43), P = 0.05). Conversely, IL-8 expression by both CD4+ and CD8+ T cells from allergic asthmatics demonstrated significant enhancement (9.93% (7.77-11.28) vs 4.14% (3.61-7.11), P = 0.05; 8.40% (6.97-10.04) vs 4.98% (3.37-6.08), P = 0.05). Examination of intracellular IFN-gamma and IL-4 revealed no significant difference in the expression of either cytokine by CD4+ T-cells from allergic asthmatics and nonasthmatics. In contrast, expression of IFN-gamma was significantly reduced in CD8+ T-cells from allergic asthmatics (24.60% (21.08-32.50) vs 48.40% (41.50-55.28), P = 0.01). CONCLUSIONS: The occurrence in mild allergic asthma of peripheral T-cell chemokine expression suggestive of a diminished Th1 response, coinciding with marginal change in cytokine profiles indicative of a Th2 response bias, confirms the importance of chemokine involvement in the etiology of allergic asthma. The ability to use whole blood culture to estimate chemokine expression in T cell subsets may ultimately provide a practical means to evaluate disease status and to monitor early intervention therapies which target chemokines.     

Immunohistochemical screening for beta6-integrin subunit expression in adenocarcinomas using a novel monoclonal antibody reveals strong up-regulation in pancreatic ductal adenocarcinomas in vivo and in vitro

AIMS: To analyse the expression of alphavbeta6, an epithelial integrin involved in wound healing and tumorigenesis, in various human carcinoma types. METHODS AND RESULTS: A new monoclonal antibody to the human beta6 subunit, 5C4, was used to locate alphavbeta6 in 157 cancers of gastroenteropancreatic and 21 of lung origin. The data were validated by analysis of alphavbeta6 extracted from histological sections. Alphavbeta6 integrin showed strongest expression in 34 pancreatic ductal adenocarcinomas (mean score 2.88 +/- 0.52), followed by 24 intestinal-type gastric carcinomas (1.45 +/- 1.06) and eight lung adenocarcinomas (1.37 +/- 1.1). Moderate expression was found in 31 diffuse-type gastric carcinomas (0.94 +/- 0.83), seven duodenal adenocarcinomas (0.8 +/- 1.34) and 26 colorectal adenocarcinomas (0.76 +/- 0.71). Little alphavbeta6 was seen in seven liver cell carcinomas and six neuroendocrine tumours. Well-differentiated carcinomas expressed more beta6 than poorly differentiated tumours. Peritumoral epithelial tissues where alphavbeta6-expressing tumours arose also expressed alphavbeta6. There was no correlation between expression of alphavbeta6 and its ligands tenascin and fibronectin in pancreatic and gastric carcinomas. Spheroid formation by pancreatic carcinoma cell lines led to alphavbeta6 up-regulation, but appeared independent of classical ligand binding to alphavbeta6. CONCLUSIONS: Our findings indicate that: (i) alphavbeta6 is overexpressed in pancreatic adenocarcinomas; (ii) alphavbeta6-positive carcinomas originate from alphavbeta6-expressing tissues; (iii) alphavbeta6 expression in tumours seems to be regulated independently from that of its ligands tenascin and fibronectin; and (iv) in-vitro overexpression of alphavbeta6 in pancreatic carcinoma cell lines accompanies spheroid formation.     

Emergence of α5β1 fibronectin- and αvβ3 vitronectin-receptor expression in melanocytic tumour progression

Cell adhesion is crucial in the process of tumour progression. As integrins are important receptor molecules involved in cell adhesion, we studied the distribution of the α1-6, αv, αIIb, β1, β3, and β4 integrin subunits in tissue sections of common naevocellular naevi ( n =22), dysplastic naevi (16), thin (24) and thick primary cutaneous melanomas (28), and melanoma metastases (25). We found correlated expression of α1/α2, of α4/α5/β3, and of α6/β4. Decrease of α6 and β4, and increase of α4 and αv were found to be correlated with melanoma progression. Furthermore, expression of α5 and β3 was detected only in primary melanoma and melanoma metastasis. Our findings indicate that during melanoma progression alterations in integrin expression occur, the most striking being emergence of α5β1 fibronectin and αvβ3 vitonectin receptor.     

Modulation of intercellular adhesion molecule 1 (ICAM-1) expression on the human mast-cell line (HMC)-1 by inflammatory mediators

The effect of inflammatory mediators on the expression of several surface adhesion molecules on the human mast-cell line (HMC)-1 was studied. By flow cytometry, it could be shown that among several surface adhesion molecules (ICAM-UCDS4, VLA-4/CD49d, Mac-UCD11b, LFA-1/CD11a, LFA-2/CD2, LFA-3/CDS8, VCAM-1), only the constitutively expressed immunoglobulin family member intercellular adhesion molecule-1 (ICAM-1) is modulated by proinflammatory cytokines on HMC-1 mast cells. Stimulation with tumor necrosis factor-a (TNF-α) and interferon-γ (IFN-γ) resulted, in addition to interleukin-(lL-)4, in selective upregulation of ICAM-1 expression. Costimulation of either IL-4 or IFN-γ with TNF-α further increased the ICAM-1 expression as compared to the stimuli alone. In contrast, stem-cell factor (SCF), granulocyte/macrophage colonystimulating factor (GM-CSF), IL-10, IL-8, monocyte chemotactic and activating factor (MCAF), and the complement split product C5a failed to modulate the expression of any adhesion molecule examined. The levels of cytoplasmic free calcium in HMC-1 mast cells were not altered by cross-linking surface ICAM-1, suggesting linkage of other intracellular signaling pathways. This cytokine-induced upregulation of ICAM-1 expression might reveal a putative regulatory mechanism of mast-cell interaction with effector cells bearing the counterparts of ICAM-1 (CD54), the molecules Mac-1 (CD11b/CD18) and leukosialin (CD43), and the principal ligand LFA-1 (CD11a/CD18).     

Expression of ICAM-1 in colon epithelial cells: an ultrastructural study performed on in vivo and in vitro models

Background Studies have suggested that in ulcerative colitis (UC), intercellular adhesion molecule-1 (ICAM-1) is involved in migration of leukocytes toward the colonic epithelium. A suitable in vitro model of chronic colonic inflammation does not exist, and the role of the epithelium is based on monolayers of cancer cells. Conflicting results exist on epithelial ICAM-1 expression, and the aim of this study was to compare the expression in various models of colonic epithelium.Materials and methods Colonic biopsies from four UC patients and four controls were examined by cryoimmuno-electron microscopy using ICAM-1-antibodies. In four other controls, the epithelium was isolated from colonic biopsies, embedded in collagen, and evaluated similarly. Isolated crypts and cultured cancer cells were stimulated with interferon- (IFN-) or tumor necrosis factor- (TNF-).Results ICAM-1 was not expressed in the biopsies. In contrast, HT29 cells and the collagen-embedded crypts expressed ICAM-1 on the apical membranes proximal to the junctional complexes when stimulated with IFN- or TNF- in a dose-related manner.Conclusions ICAM-1 is not expressed on colonic epithelium in vivo. However, both colonocytes and HT29 cells were capable of expressing ICAM-1 on their apical membranes in response to supraphysiologic cytokine concentrations. These observations question the justification of extrapolating observations from colon cancer cell lines to in vivo inflammatory conditions.     

Involvement of tumor cell integrin alpha v beta 3 in hematogenous metastasis of human melanoma cells

Early metastasis is the primary cause of death in melanoma patients. The adhesion receptor integrin αvβ3 contributes to tumor cell functions that are potentially involved in melanoma growth and metastasis. We tested whether integrin αvβ3 supports metastasis of human melanoma cells when injected into the bloodstream of immune deficient mice. Comparing variants of the same melanoma cell type that expressed either αvβ3, αIIbβ3 or no β3 integrin, we found that only αvβ3 strongly supported metastasis. Inhibition of tumor cell αvβ3 function reduced melanoma metastasis significantly and prolonged animal survival. To understand mechanisms that allow αvβ3, but not αIIbβ3 to support melanoma metastasis, we analyzed proteolytic and migratory activities of the melanoma cell variants. Melanoma cells expressing αvβ3, but not those expressing αIIbβ3 or no β3 integrin, produced the active form of metalloproteinase MMP-2 and expressed elevated mRNA levels of MT1-MMP and TIMP-2. This indicates an association between αvβ3 expression and protease processing. Furthermore, αvβ3 expression was required for efficient melanoma cell migration toward the matrix proteins fibronectin and vitronectin. The results suggest that expression of integrin αvβ3 promotes the metastatic phenotype in human melanoma by supporting specific adhesive, invasive and migratory properties of the tumor cells and that the related integrin αIIbβ3 cannot substitute for αvβ3 in this respect. This revised version was published online in July 2006 with corrections to the Cover Date.     

Heterogenous glycosylation of ICAM-3 and lack of interaction with Mac-1 and p150,95

Intercellular adhesion molecule (ICAM)-1, ICAM-2, and ICAM-3 have been identified as counter-receptors for the leukocyte integrin lymphocyte function-associated antigen 1 (LFA-1). The other leukocyte integrins, Mac-1 and p150,95, also interact with ICAM-1. ICAM-1 and ICAM-3 are highly homologous, and an undefined ligand for Mac-1 is presnt on neutrophils where ICAM-3 is well expressed. In addition, glycosylation has been shown to affect the interaction of ICAM-1 with Mac-1. We therefore sought to characterize ICAM-3 heterogeneity and determine whether ICAM-3 was a ligand for either Mac-1 or p150,95. Despite extensive differences in N-linked glycosylation, ICAM-3 purified from lymphoid cells and from neutrophils supports adhesion of LFA-1-bearing cells equally well; however, neither supports adhesion of Mac-1 or p150,95-expressing chinese hamster ovary cell transfectants. Similarly, purified Mac-1 does not support adhesion of ICAM-2 or ICAM-3-expressing L cell transfectants. ICAM-3 on neutrophils does not participate in Mac-1-dependent homotypic aggregation. Thus, ICAM-3 is not a counter-receptor for either Mac-1 or p150,95.     

Colonic epithelial cells induce endothelial cell expression of ICAM-1 and VCAM-1 by a NF-kappaB-dependent mechanism.

Epithelial cells are positioned in close proximity to endothelial cells. A non-contact coculture system was used to investigate whether colonic epithelial cells activated with various cytokines are able to provide signals that can modulate ICAM-1 and VCAM-1 expression on endothelial cells. Coculture of human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (HMEC-1) with TNF-alpha/IFN-gamma-stimulated human colon epithelial cell lines led to a significant up-regulation of endothelial ICAM-1 and VCAM-1 expression. Increased ICAM-1 and VCAM-1 expression by endothelial cells was accompanied by an increase in endothelial cell NF-kappaB p65 and NF-kappaB-DNA-binding activity. Inhibition of endothelial NF-kappaB activation using the proteosome inhibitors MG-132 and BAY 11-7082 resulted in a significant decrease of ICAM-1 expression, indicating an important role for NF-kappaB in this response. This cross-talk may represent a biological mechanism for the gut epithelium to control the colonic inflammatory response and the subsequent immune cell recruitment during inflammation.     

Integrin modulation and signaling in leukocyte adhesion and migration

Summary:  The movement of leukocytes from the blood into peripheral tissues plays a key role in immunity as well as chronic inflammatory and autoimmune diseases. The shear force of blood flow presents special challenges to leukocytes as they establish adhesion on the vascular endothelium and migrate into the underlying tissues. Integrins are a family of cell adhesion and signaling molecules, whose function can be regulated to meet these challenges. The affinity of integrins for their vascular ligands can be stimulated in subseconds by chemoattractant signaling. This aids in inducing leukocyte adhesion under flow conditions. Further, linkage of these integrins to the actin cytoskeleton also helps to establish adhesion to the endothelium under flow conditions. In the case of α4β1 integrins, this linkage of the integrin to the cytoskeleton is mediated in part by the binding of paxillin to the α4 integrin subunit and the subsequent binding of paxillin to the cytoskeleton molecule talin. The movement of leukocytes along the vascular endothelium and in between endothelial cells requires the temporal and spatial regulation of small guanosine triphosphatases, such as Rac1. We describe mechanisms through which α4β1 integrin signaling regulates appropriate Rac activation to drive leukocyte migration.     

Bleomycin induces IL-8 and ICAM-1 expression in microvascular pulmonary endothelial cells

To investigate the pathomechanisms of bleomycin-induced early inflammation of lung parenchyma which is known to result in pulmonary fibrosis, we examined the in vitro effect of bleomycin (BLM) on primary human pulmonary microvascular endothelial cells (HMVEC-L).

After incubation of microvascular endothelial cells with BLM we detected an induced phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) by immunoblotting. Further, after BLM-exposure an increased concentration of interleukin-8 (IL-8) in culture supernatant and an increased expression of intercellular adhesion molecule-1 (ICAM-1, CD54) on the cell surface have been observed. Real-time PCR revealed up-regulated mRNA expression levels of both, IL-8 and ICAM-1 after treatment with BLM. Finally, pre-treatment with a selective p38 MAPK-inhibitor, SB 203580, potently reduced the BLM-induced up-regulation of IL-8 expression but did not show any effect on expression of ICAM-1.

These results demonstrate that BLM induces the expression of pro-inflammatory molecules in the pulmonary microvascular endothelium, which thereby may actively contribute to the development of early inflammation and later fibrosis of the lung. Furthermore, investigating the effect of an inhibitor of p38 MAPK the data indicate the involvement of p38 MAPK-dependent as well as p38 MAPK-independent mechanisms in the effects of BLM on the pulmonary microvasculature.     

Keratinocyte growth factor (KGF) decreases ICAM-1 and VCAM-1 cell expression on bronchial epithelial cells

Activation of leucocytes during airway inflammatory reaction involves adhesion to bronchial epithelial cells (BEC), a process implicating specific interactions between glycoproteins with epithelial cell surface proteins, mainly intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). In this study, the effect of keratinocyte growth factor (KGF), a growth factor involved in pulmonary epithelium repair, was evaluated on adhesion molecule expression with BEAS-2B cells and BEC and granulocyte adherence to BEAS-2B. The modulation by KGF of membrane and mRNA expression of ICAM-1 and VCAM-1 was studied on confluent cells stimulated or not with tumour necrosis factor-alpha (TNF) (200 UI/ml) or TNF and interleukin (IL)-4 (50 UI/ml and 10 ng/ml). Levels of soluble-(s)ICAM-1 and sVCAM-1 were measured by ELISA. Although moderately, KGF significantly decreased membrane ICAM-1 expression in unstimulated BEAS-2B cells (24% inhibition at 100 ng/ml) or in TNF- or TNF + IL-4-stimulated cells (22.5 and 18.7% inhibition, respectively). Treatment with KGF tended to decrease VCAM-1 expression in TNF- and TNF + IL-4-stimulated BEAS-2B (P = n.s. and P < 0.05, 14 and 15% inhibition, respectively). In primary culture of BEC, adhesion molecule expression was also reduced. ICAM-1 and VCAM-1 mRNA expression were also inhibited by KGF. Levels of sICAM-1 and sVCAM-1 were not significantly increased in supernatants from KGF-treated cells (30% and 24% increase at 100 ng/ml, respectively) compared to controls. Moreover, KGF decreased by 31% the adherence of neutrophils to TNF-activated BEAS-2B. In conclusion, KGF decreases ICAM-1 and VCAM-1 expression and neutrophil adherence in BEC. These suggest its involvement in the resolution of the inflammatory reaction.     

GM-CSF, IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, ICAM-1 and VCAM-1 gene expression and cytokine production in human duodenal fibroblasts stimulated with lipopolysaccharide, IL-1 alpha and TNF-alpha.

The role of mucosal fibroblasts in intestinal inflammatory reactions is not known. In this study, we demonstrate that fibroblasts grown from histologically normal human duodenal biopsy tissues expressed mRNA genes for granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) when stimulated with lipopolysaccharide (LPS) or IL-1 alpha. The increased mRNA expression of GM-CSF, IL-1 alpha, IL-1 beta, IL-6 and IL-8 in response to IL-1 alpha and LPS stimulation was time- and dose-dependent. In contrast, IL-10 was weakly expressed when fibroblasts were stimulated with LPS, IL-1 alpha or tumour necrosis factor-alpha (TNF-alpha), but the expression was enhanced in the presence of cycloheximide combined with optimal concentrations of LPS, IL-1 alpha or TNF-alpha, IL-1 alpha was a more potent stimulator than LPS for GM-CSF, IL-6, IL-8 and IL-10 expression, but not for IL-1 alpha and IL-1 beta. Increased GM-CSF, IL-6 and IL-8 gene expression was associated with the production of cytokine proteins in culture supernatant, but IL-1 alpha and IL-1 beta remained undetectable. Dexamethasone suppressed both gene expression and protein production of GM-CSF, IL-6 and IL-8 when fibroblasts were exposed to IL-1 alpha. TNF-alpha stimulated the release of GM-CSF, IL-6 and IL-8 and, combined with IL-1 alpha, cytokine production was enhanced synergistically. Finally, both LPS and IL-1 alpha up-regulated ICAM-1 and VCAM-1 gene expression. These findings implicate duodenal fibroblasts in the initiation and/or regulation of intestinal inflammation.     

Terfenadine exerts antiallergic activity reducing ICAM-1 expression on nasal epithelial cells in patients with pollen allergy

Background: Rhinoconjunetivitis caused by pollen allergy is characterized by typical signs and symptoms and mucosal infiltration by inflammatory cells during the pollen season. It has recently been demonstrated that the adhesion molecule system is deeply involved in cell-to-cell interaction during the inflammatory response which follows allergic reactions. Objective: The aim of the present study (placebo-controlled, double-blind, randomized) was the evaluation of the antiallergic activity of Terfenadine in the model of the allergic rhinitis due to natural pollen exposure. Methods: Two groups of patients with pollen allergy were enrolled in this study. Ten patients were treated with Terfenadine (120mg/die) for 7 days and 10 with placebo. Evaluation criteria were: (a) clinical: signs and symptoms (recorded daily in a dian card by patients): (b) cytological: inflammatory cell count (neutrophils, eosinophils, metachromatic cells) from nasal lavage at T0 and T7; (c) immunocytochemical: ICAM-1/CD54 expression on nasal epithelial cells at T0 and T7; and (d) mediators dosage (ECP-MPO) on nasal lavage at T0 and T7. Results: As opposed to the placebo group, patients treated with Terfenadine showed a significant improvement of both symptoms (P< 0.022) and signs P< 0.001), a significant reduction of inflammatory cells infiltrate (P< 0.005), of ECP levels (P < 0.002) and ICAM-I expression on nasal epithelial cells (P < 0.005). Conlusions: In conclusion, these data demonstrate that Terfenadine exerts antiallergic activity since it is able to reduce inflammatory cell infiltrate and downregulates ICAM-1 expression.     

眼部蠕形螨寄居患者结膜上皮ICAM-1和HLA-DR的表达和意义

目的:探讨眼部蠕形螨寄居患者结膜上皮ICAM-1和HLA-DR的表达和意义。方法:选择痤疮、脂溢性皮炎以及类固醇皮炎眼部蠕形螨检查为阳性的患者共58例为蠕形螨寄居组,另选50例无面部疾病眼部蠕形螨检查阴性的健康成人,作为正常对照组。用流式细胞术联合印迹细胞学检测细胞表面分子的方法检测结膜上皮细胞ICAM-1和HLA-DR的表达阳性率及荧光强度。结果:与正常对照组相比,蠕形螨寄居组患者结膜上皮细胞中ICAM-1和HLA-DR的阳性率和荧光强度均明显提高,差异具有统计学意义(P<0.05)。结论:眼部蠕形螨寄居患者结膜上皮中ICAM-1和HLA-DR的表达增强。     

Quantification and localization of HLA-DR and intercellular adhesion molecule-1 (ICAM-1) molecules on bronchial epithelial cells of asthmatics using confocal microscopy.

Earlier studies have shown that 17 alpha-hydroxylase (P450c17), steroid 21-hydroxylase (P450c21) and side-chain cleavage enzyme (P450scc) are the main autoantigens recognized by sera from patients with Addison's disease associated with autoimmune polyglandular syndrome type I (APS I). In this study we tried to identify the autoantigenic epitopes on P450c17 and compared the identified sequences with corresponding regions in two other adrenal autoantigens, P450scc and P450c21. A series of P450c17 cDNA fragments was expressed in Escherichia coli and the recognition of the corresponding protein fragments by patient sera was tested by immunoblotting. Four distinct epitope regions (ER) were found: ER1 (amino acids 122-148), ER2 (280-304), ER3 (396-432) and ER4 (466-508). B cell epitope prediction analysis showed that the four identified ERs were all located in regions of high predicted antigenicity. Homology search revealed that ER3 and ER4 but not ER1 and ER2 were related to similar sequences on P450c21. No significant homologies with P450scc in these regions were found. Although all three P450 cytochromes are genuine autoantigens this finding suggests that the autoantibody reaction against P450c17 and P450c21 can partly be a result of immunological cross-reactivity.