Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ADHESIONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources

Effects of the very late adhesion molecule 4 antagonist WAY103 on human peripheral blood eosinophil vascular cell adhesion molecule 1-dependent functions.

BACKGROUND: Eosinophil infiltration to the lung in allergic inflammation can be initiated by the tethering of circulating cells through very late adhesion molecule 4 (VLA-4; alpha4beta1, CD49d/CD29) to vascular cell adhesion molecule 1 (VCAM-1) expressed on pulmonary vascular endothelium. Small-molecule VLA-4 antagonists have been proposed as a therapeutic mechanism to prevent eosinophil infiltration in asthma; however, they might affect other eosinophil functions. OBJECTIVE: The small-molecule VLA-4 antagonist (2S)-3-(4-Dimethylcarbamoyloxyphenyl)-2-{[(4R)-5,5-dimethyl-3-(1-methyl-1H-pyrazole-4 sulfonyl)thiazolidine-4-carbonyl]amino}propionic acid (WAY103) was assessed for its effects on eosinophil VLA-4-dependent functions, including adhesion, migration, respiratory burst, and degranulation. METHODS: Human peripheral blood eosinophils were preincubated with WAY103, anti-alpha4, and/or anti-beta2 integrin mAbs and then assessed for adhesion to recombinant VCAM-1, intercellular adhesion molecule 1, and endothelial cell monolayers. Transmigration was measured by using human pulmonary microvascular endothelial cell monolayers and Transwell filters. Superoxide anion generation was determined by means of cytochrome C reduction and degranulation by means of eosinophil-derived neurotoxin release. RESULTS: WAY103 inhibition of eosinophil adhesion to recombinant VCAM-1 was dose dependent (63% inhibition with 100 nM WAY103, P < .04) and comparable with inhibition caused by anti-alpha4 mAb (60.1% inhibition). Although pretreatment with WAY103 also decreased eosinophil adhesion to TNF-alpha plus IL-4-activated human pulmonary microvascular endothelial cell monolayers, it did not prevent eosinophil transendothelial migration in response to RANTES. Finally, WAY103 inhibited VCAM-1-stimulated superoxide generation but enhanced cytokine-activated eosinophil-derived neurotoxin degranulation. CONCLUSION: Although small-molecule VLA-4 antagonists, such as WAY103, might reduce eosinophil adhesion, this approach might not be sufficient to eliminate this cell from in vivo allergic airway inflammatory participation and could even promote specific cell activation.

Adolescent↗

Expression of leucocyte-endothelial adhesion molecules is limited to intercellular adhesion molecule-1 (ICAM-1) in the lung of pneumoconiotic patients: role of tumour necrosis factor-alpha (TNF-alpha).

Coal workers' pneumoconiosis (CWP) is characterized by a chronic inflammatory lung reaction associated with macrophage accumulation in alveolar spaces. In this study, we investigated in CWP the implication of adhesion molecules such as E-selectin, ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1) and the role of TNF-alpha which is one of the cytokines inducing their expression. Adhesion molecule expression was analysed by immunohistochemistry on lung biopsies from patients with CWP and from healthy subjects. In parallel, soluble adhesion molecules were detected in bronchoalveolar lavage fluids (BALF) from patients by specific ELISA. The involvement of TNF in the induction of these adhesion molecules was measured (i) by immunohistochemistry on sections from lung fragments, and (ii) by evaluating in vitro the expression of adhesion molecules on endothelial cells and on alveolar epithelial cells in the presence of alveolar macrophage supernatants. In control subjects, a weak staining of ICAM-1 was detected only in alveolar walls, while E-selectin and VCAM-1 were undetectable. In pneumoconiotic patients, ICAM-1 was expressed at a high level by endothelium, by alveolar and bronchial epithelial cells and by alveolar macrophages. E-selectin and VCAM-1 expression remained undetectable. Measurement of soluble adhesion molecule showed that only the concentration of sICAM-1 was significantly increased in BALF from patients with CWP compared with controls. The involvement of TNF in this ICAM-1 expression was shown by the in vitro effect of alveolar macrophage supernatants on adhesion molecule expression by endothelial cells and epithelial cells (this effect was neutralized by anti-TNF antibodies) and by the increased production of TNF in the lung of pneumoconiotic patients. These data provide evidence for the involvement of ICAM-1, induced at least in part by alveolar macrophage-derived TNF, in the development of the inflammatory reaction in CWP.

Aged↗

Novel cytokine-independent induction of endothelial adhesion molecules regulated by platelet/endothelial cell adhesion molecule (CD31).

Tumor necrosis factor-alpha, interleukin-1, and endotoxin stimulate the expression of vascular endothelial cell (EC) adhesion molecules. Here we describe a novel pathway of adhesion molecule induction that is independent of exogenous factors, but which is dependent on integrin signaling and cell-cell interactions. Cells plated onto gelatin, fibronectin, collagen or fibrinogen, or anti-integrin antibodies, expressed increased amounts of E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1. In contrast, ECs failed to express E-selectin when plated on poly-L-lysine or when plated on fibrinogen in the presence of attachment-inhibiting, cyclic Arg-Gly-Asp peptides. The duration and magnitude of adhesion molecule expression was dependent on EC density. Induction of E-selectin on ECs plated at confluent density was transient and returned to basal levels by 15 h after plating when only 7 +/- 2% (n = 5) of cells were positive. In contrast, cells plated at low density displayed a 17-fold greater expression of E-selectin than did high density ECs with 57 +/- 4% (n = 5) positive for E-selectin expression 15 h after plating, and significant expression still evident 72 h after plating. The confluency-dependent inhibition of expression of E-selectin was at least partly mediated through the cell junctional protein, platelet/endothelial cell adhesion molecule-1 (PECAM-1). Antibodies against PECAM-1, but not against VE-cadherin, increased E-selectin expression on confluent ECs. Co- culture of subconfluent ECs with PECAM-1- coated beads or with L cells transfected with full-length PECAM-1 or with a cytoplasmic truncation PECAM-1 mutant, inhibited E-selectin expression. In contrast, untransfected L cells or L cells transfected with an adhesion-defective domain 2 deletion PECAM-1 mutant failed to regulate E-selectin expression. In an in vitro model of wounding the wound front displayed an increase in the number of E-selectin-expressing cells, and also an increase in the intensity of expression of E-selectin positive cells compared to the nonwounded monolayer. Thus we propose that the EC junction, and in particular, the junctional molecule PECAM-1, is a powerful regulator of endothelial adhesiveness.

Blood Platelets↗

CD44 antibody stimulates adhesion of peripheral blood T cells to keratinocytes through the leukocyte function-associated antigen-1/intercellular adhesion molecule-1 pathway.

Close contact between T lymphocytes and keratinocytes is an important feature of many inflammatory skin diseases. In vitro studies showed that stimulation of keratinocytes with interferon-gamma or tumor necrosis factor-alpha and of T cells with phorbol esters results in a leukocyte function-associated antigen (LFA)-1/intercellular adhesion molecule (ICAM)-1-mediated adhesion. The present study was performed to investigate the role of the CD44 molecule in keratinocyte/T-cell binding. The CD44 class of lymphocyte adhesion receptors is involved in lymphocyte binding to high endothelial venules and to extracellular matrix compounds and is therefore important in lymphocyte recirculation and homing. Moreover, CD44 can act as a co-stimulating signal in T-cell activation and promotes homotypic adhesion of in vitro cultured CD3-stimulated T cells. Using a cell adhesion assay a sixfold increase in T-cell/keratinocyte adhesion was found after pre-incubating the T cells with anti-CD44. This increased adhesion was found to require an intact cytoskeleton, to be energy and magnesium dependent, and could be completely inhibited by anti-LFA-1 and anti-ICAM-1. Pretreatment of T cells with hyaluronic acid, a ligand for CD44 and an extracellular matrix compound in the dermis and epidermis, did not affect T-cell/keratinocyte adhesion.

Antibodies, Monoclonal↗

Candida albicans expresses a focal adhesion kinase-like protein that undergoes increased tyrosine phosphorylation upon yeast cell adhesion to vitronectin and the EA.hy 926 human endothelial cell line.

The signaling pathways triggered by adherence of Candida albicans to the host cells or extracellular matrix are poorly understood. We provide here evidence in C. albicans yeasts of a p105 focal adhesion kinase (Fak)-like protein (that we termed CaFak), antigenically related to the vertebrate p125Fak, and its involvement in integrin-like-mediated fungus adhesion to vitronectin (VN) and EA.hy 926 human endothelial cell line. Biochemical analysis with different anti-chicken Fak antibodies identified CaFak as a 105-kDa protein and immunofluorescence and cytofluorimetric analysis on permeabilized cells specifically stain C. albicans yeasts; moreover, confocal microscopy evidences CaFak as a cytosolic protein that colocalizes on the membrane with the integrin-like VN receptors upon yeast adhesion to VN. The protein tyrosine kinase (PTK) inhibitors genistein and herbimycin A strongly inhibited C. albicans yeast adhesion to VN and EA.hy 926 endothelial cells. Moreover, engagement of alpha v beta 3 and alpha v beta 5 integrin-like on C. albicans either by specific monoclonal antibodies or upon adhesion to VN or EA.hy 926 endothelial cells stimulates CaFak tyrosine phosphorylation that is blocked by PTK inhibitor. A role for CaFak in C. albicans yeast adhesion was also supported by the failure of VN to stimulate its tyrosine phosphorylation in a C. albicans mutant showing normal levels of CaFak and VNR-like integrins but displaying reduced adhesiveness to VN and EA.hy 926 endothelial cells. Our results suggest that C. albicans Fak-like protein is involved in the control of yeast cell adhesion to VN and endothelial cells.

Antigens, Bacterial↗

Adhesion of memory lymphocytes to vascular cell adhesion molecule-1-transduced human vascular endothelial cells under simulated physiological flow conditions in vitro.

The accumulation of mononuclear leukocytes is an early and persistent finding in atherosclerotic plaques. These mononuclear leukocytes are mostly monocyte-derived, but up to 20% are lymphocytes, predominantly CD4+ CD45RO+ (memory) T cells. To evaluate the potential of adenovirus vectors for studies of mononuclear leukocyte recruitment in vitro, we studied the effects of adenovirus vectors per se on human umbilical vein endothelial cells (HUVECs), a well-characterized in vitro model of vascular endothelium. A recombinant adenovirus containing the seven-domain isoform of rabbit vascular cell adhesion molecule-1 (rVCAM-1) was constructed and used to study lymphocyte adhesion under defined laminar flow conditions in transduced HUVEC monolayers. No increase in basal HUVEC surface expression of the inducible endothelial adhesion molecules and markers of activation, E-selectin and VCAM-1, was noted across a broad range of multiplicity of infection. A modest dose-dependent increase in surface intercellular adhesion molecule-1 expression was detectable by flow cytometry at an MOI of > 30 plaque-forming units per cell. Under defined laminar flow from 1.5 to 0.5 dyne/cm2, the adenovirus vector carrying rVCAM-1 mediated stable adhesion of both a Jurkat T-cell line and primary human CD4+ CD45RO+ (memory) T cells. Monoclonal antibodies to alpha 4-integrin or rVCAM-1 abolished adhesion, whereas monoclonal antibodies to CD18 or P-selectin had no effect. We conclude that adenoviral gene transfer in useful for studies of VCAM-1-dependent leukocyte adhesion in vitro and that endothelial expression of VCAM-1 alone, in the absence of over endothelial cell activation, is sufficient under simulated physiological flow conditions to support adhesion of memory T cells, the predominant lymphocyte subset in atherosclerotic plaque.

Adenoviridae↗

The neural cell adhesion molecule antibody blocks cold water swim stress-induced analgesia and cell adhesion between lymphocytes and cultured dorsal root ganglion neurons.

BACKGROUND: Opioid-containing immune cells migrate in a site-directed manner into inflamed tissue and adhere to sensory nerve fibers. These cells release opioid peptides in close proximity to these fibers, thereby avoiding localized degradation by peptidases, and delivering opioid peptides proximal to opioid receptors to provide antinociception. METHODS: The effects of the anti-neural-cell-adhesion molecule (anti-NCAM) were assessed on cold water swim stress-induced antinociception in Wistar rats with Freund's adjuvant-induced inflammation of one hindpaw. Algesiometry was assessed for both thermal and mechanical stimuli. Cell adhesion experiments examining the effects of beta-endorphin and antibodies to NCAM and intercellular cell adhesion molecule-1 and were performed on cultured dorsal root ganglion neurons and isolated lymphocytes. Lymphocyte binding was determined by fluorescence using calcein AM loaded into freshly isolated lymphocytes. RESULTS: The direct adhesion between lymphocytes and cultured sensory neurons was inhibited by anti-NCAM. This adhesion was also demonstrated to be opioid dependent, with lymphocyte adhesion to cultured sensory neurons reduced in the presence of 1 microM beta-endorphin, which was reversed by 100 microM naloxone. Moreover, anti-NCAM blocked cold-water-swim-induced analgesia in inflamed paws both to thermal and mechanical stimuli. However, anti-NCAM did not affect fentanyl-induced antinociception. CONCLUSIONS: This study provides insight into the role of cell adhesion molecules in lymphocyte adhesion to sensory neurons and a link to immune-derived antinociception.

Analgesia↗

[In vitro effect of all-trans retinoic acid on cell adhesion molecule expression and adhesion capacity of bone marrow stromal cells in patients received peripheral blood stem cell transplantation].

The aim of this study was to evaluate the effect of all-trans retinoic acid (ATRA) on cell adhesion molecule expression and adhesion capacity of bone marrow stromal cells (BMSC) in patients after conditioning treatment for peripheral blood stem cell transplantation (PBSCT). BMSC of 27 patients before and after conditioning treatment for PBSCT were cultured in vitro. After treated with ATRA at 0.01, 0.1, or 1 micromol/L, expression of intercellular adhesion molecule-1 (ICAM-1) protein and vascular adhesion molecule-1 (VCAM-1) protein were detected by flow cytometry, and soluble ICAM-1 (sICAM-1) protein was determined by using radioimmunoassay. Then BMSC was co-cultured with CD34+ cells, and adhesion rate of BMSC to CD34+ cells was measured. The results showed that after pretreatment with conditioning regimen for PBSCT, the expressions of ICAM-1 and VCAM-1 proteins in BMSC and the expression level of sICAM-1 protein in supernatant of BMSC culture were down-regulated, and the adhesion rate of BMSC to CD34+ cells was decreased, after administration of ATRA, the expression of ICAM-1 protein in BMSC, sICAM-1 protein in culture medium and adhesion rate of BMSC to CD34+ cells all increased significantly, but expression of VCAM-1 protein changed no significantly. It is concluded that the ATRA can partly restore adhesion function of BMSC injured by pretreatment for PBSCT and contribute to hematopoietic reconstitution.

Adolescent↗

Ligand-induced adhesion to activated endothelium and to vascular cell adhesion molecule-1 in lymphocytes transfected with the N-formyl peptide receptor.

Binding of FMLP to the neutrophil N-formyl peptide receptor (FPR) transmits signals through pertussis toxin-sensitive G proteins triggering Ca2+ flux, superoxide production, granule exocytosis, and neutrophil aggregation and adhesion involving the beta 2 (CD18) integrins. Expression of the FPR in mouse fibroblasts or human kidney cells has been shown to confer an N-formyl peptide-inducible Ca2+ flux in transfectants. Here we demonstrate that the transfected receptor can also support ligand-induced alterations in cellular adhesion. We established stable transfectants of mouse L1-2 pre-B cells with cDNA for human FPR (L1-2 FPR cells). The transfectants bind N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein with 1.4 x 10(5) sites per cell and a dissociation constant of 3.3 nM. Stimulation with FMLP induces a transient Ca2+ flux. FMLP also triggers adhesion of L1-2 FPR cells to TNF-alpha- or LPS-activated bEnd3 cells (mouse brain-derived endothelial cells) and to purified mouse VCAM-1. Binding is inhibited by Abs to VCAM-1 and to the alpha-chain of its lymphocyte receptor (the alpha 4 beta 1 integrin, VLA-4). Stimulation with FMLP does not induce a change in cell surface expression of alpha 4. Induced adhesion to VCAM-1 is rapid, detectable at the earliest times measurable (30 to 60 s after FMLP addition), and is inhibited by pertussis toxin. We conclude that FPR can mediate integrin activation not only in neutrophils but also in lymphocytes, and can trigger rapid adhesion via lymphocyte alpha 4 beta 1. The adhesion of lymphocytes is critical to their migration and targeting; our results suggest the possibility of manipulating adhesive responses through expression of chemoattractant receptors in lymphoid cells engineered for cellular therapy, allowing targeted adhesion and potentially migration in response to locally administered ligands.

Animals↗

T lymphocyte adhesion to human brain pericytes is mediated via very late antigen-4/vascular cell adhesion molecule-1 interactions.

T cell adhesion to the brain microvascular endothelium and subsequent migration into the brain parenchyma is one of the major events in the development of multiple sclerosis (MS). Interactions of the T cell integrin very late antigen-4 (VLA-4) with its receptor, vascular cell adhesion molecule-1 (VCAM-1) have been described to be of crucial importance for the development of MS. We investigated the expression of these adhesion molecules in MS brain tissue by immunohistochemical analysis, and studied their functional involvement in an in vitro T cell adhesion assay. A number of other adhesion molecules were studied for comparison. In cryosections of several MS brains, expression of VCAM-1 was demonstrated not only on the endothelium of vessels surrounding MS plaques, but also in perivascular positions, suggesting expression by pericytes. T cells adhered to both cell types in vitro. Both LFA-1/intercellular adhesion molecule-1 and VLA-4/VCAM-1 interactions were equally involved in the adhesion of T cells to TNF-alpha-stimulated endothelial cells. However, adhesion of T cells to TNF-alpha-stimulated pericytes was clearly dominated by VLA-4/VCAM-1 interactions. These results indicate that pericytes, next to endothelial cells, may play an important role in regulating T cell infiltration into the central nervous system.

Brain↗

Inflammatory cytokines up-regulate intercellular adhesion molecule-1 expression on primary cultured mouse hepatocytes and T-lymphocyte adhesion.

We investigated the effect of inflammatory cytokines on the intercellular adhesion molecule-1 expression on primary cultured murine hepatocytes. Tumor necrosis factor-alpha, interferon-gamma and interleukin-1 alpha up-regulated the intercellular adhesion molecule-1 expression on hepatocytes in a dose-dependent fashion; however, interleukin-6 did not. On the basis of kinetic analysis, the expression level reached a peak 24 hr after stimulation, and both cycloheximide and actinomycin D inhibited the expression. Furthermore, T lymphocytes bind more to interferon-gamma-stimulated hepatocytes than to unstimulated hepatocytes. The binding was dependent on the concentration of interferon-gamma. The binding was also up-regulated by stimulating T lymphocytes with phorbol myristate acetate. Tumor necrosis factor-alpha and interleukin-1 alpha demonstrated the same effect as interferon-gamma, whereas interleukin-6 did not increase T-lymphocyte adhesion to the hepatocytes. The adhesion induced by interferon-gamma or tumor necrosis factor-alpha was inhibited by antibody against either intercellular adhesion molecule-1 or lymphocyte function-associated antigen-1, a ligand for intercellular adhesion molecule-1, but was not inhibited by CD44 antibodies. These results demonstrate that inflammatory lymphokines enhance the T-lymphocyte adhesion to primary cultured hepatocytes by up-regulating the intercellular adhesion molecule-1 expression on the stimulated hepatocytes by activating the de novo pathway. This mechanism may play an important role in the pathogenesis of hepatitis.

Animals↗

Inhibition of cell adhesion by microspheres coated with recombinant soluble intercellular adhesion molecule-1.

Murine recombinant soluble intercellular adhesion molecule-1 (sICAM-1) was produced and characterized. When immobilized on plastic microtiter wells, sICAM-1 efficiently mediated LFA-1-dependent cell adhesion, indicating that the purified protein retained the ability to bind to LFA-1. However, sICAM-1 in solution, at concentrations up to 100 micrograms/ml, was incapable of inhibiting the phorbol ester-induced homotypic aggregation of lymphocytes, the adhesion of T cells to plastic immobilized sICAM-1, and CTL effector function, all of which are mediated by intercellular adhesion molecule-1:LFA-1 interaction. In contrast, uniform polystyrene microspheres coated with sICAM-1 bound specifically to LFA-1+ cells and efficiently inhibited the adhesion of T cells to immobilized sICAM-1. The sICAM-1-coated microspheres also inhibited CTL function, but the inhibition was only partial. These results suggest that although monomeric sICAM-1 cannot competitively inhibit cell adhesion mediated by intercellular adhesion molecule-1 and LFA-1, microspheres coated with sICAM-1 can inhibit such cell adhesion.

Animals↗

Cytokine-regulated expression of E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in human microvascular endothelial cells.

Endothelial cells (EC) recruit circulating leukocytes to sites of inflammation, partly by expression of endothelial-leukocyte adhesion molecules. Whereas the regulation of some adhesion molecules is well characterized in cultured HUVEC, similar data for microvascular human test systems are limited. We studied the cytokine-regulated expression of vascular cell adhesion molecules E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) in cultured human intestinal microvascular endothelial cells (HIMEC). E-selectin and VCAM-1 were induced, and ICAM-1 was enhanced, in a dose-dependent fashion after stimulation with IL-1beta, TNF-alpha, and LPS. Each adhesion molecule displayed characteristic time-related responses comparable to those obtained with HUVEC, and each molecule supported adhesion of leukocytes. Notable disparities between the two endothelial test systems were that 1) expression of total cellular E-selectin (but not surface membrane expression) was sustained after 72 h of IL-1beta stimulation in HIMEC, contrasting a rapid biphasic response in HUVEC; 2) LPS did not maintain prolonged expression of ICAM-1 and VCAM-1 in HIMEC; and 3) VCAM-1 protein was dose-dependently up-regulated by IL-4 in HUVEC, peaking after 8 h, while IL-4 had only a negligible effect on the expression of this protein in HIMEC. In conclusion, the regulation of these adhesion molecules appears to be somewhat different in HIMEC compared with HUVEC, and the differences from available data on skin-derived microvascular endothelial cell cultures are to some extent substantial. Our findings document the importance of using relevant endothelial cell culture systems for studies of leukocyte-endothelial cell interactions.

Base Sequence↗

CD99 (MIC2) regulates the LFA-1/ICAM-1-mediated adhesion of lymphocytes, and its gene encodes both positive and negative regulators of cellular adhesion.

Despite the fact that integrin-mediated lymphocyte adhesion is a crucial event for an appropriate immune response, little is known about the mechanisms that control the adhesion and deadhesion processes generated by the engagement of CD99 between various types of immune cells. Here we report that the CD99 gene encodes two distinct proteins with opposite functions in the LFA-1/intercellular adhesion molecule 1 (ICAM-1)-mediated cell adhesion process. The two forms of the CD99 protein are produced by alternative splicing of the CD99 gene transcript. The major form induced homotypic adhesion of the human B lymphoblastoid cell line IM-9, whereas the minor, truncated form inhibited the adhesion process. Activation of the major form of CD99 with anti-CD99 monoclonal antibodies induced rapid aggregation of IM-9 cells, which was blocked by the addition of mAbs to LFA-1 or intracellular adhesion molecule 1. Overexpression of the minor truncated form of CD99 markedly down-regulated the expression of LFA-1. The two forms of CD99 are differentially expressed in most human cells tested and are highly conserved in monkey. Taken together, these observations suggest that the two forms of CD99 function in vivo in both positive and negative regulation of LFA-1-mediated adhesion of lymphocytes during an immune response.

12E7 Antigen↗