Leukocyte integrin very late antigen-4/vascular cell adhesion molecule-1 adhesion pathway in splanchnic artery occlusion shock

Two MAIPA (monoclonal antibody [MAb] immobilization of platelet antigen) assays were performed to determine (a) autoantibodies to platelet glycoproteins (GP) and (b) serum antibodies recognizing mouse MAbs used in the assay. In MAIPA I, control platelets were incubated simultaneously with human serum and a mouse MAb to a platelet glycoprotein (GP IIb-IIIa, Ib-IX, Ia-IIa, IV and p24). In MAIPA II, the control platelets were incubated first with the human serum and then, after washing, with the selected mouse MAb. A series of 25 patients with autoimmune thrombocytopenic purpura (ATP) associated or not with other autoimmune states were examined. Autoantibodies (both MAIPA I and MAIPA II positive) or anti-mouse Abs (MAIPA I positive and MAIPA II negative) were frequent in both groups of patients. Statistically significant differences existed in the incidence of anti-mouse Abs between patients (56.5%) and healthy donors (10%). This suggests that their production may be related to thrombocytopenias associated with autoimmune disease. We speculate that the presence of anti-mouse antibodies could reflect an abnormality in the immunological modulation of the idiotypic network.     

Interference of nonsteroidal antiinflammatory drugs with very late activation antigen 4/vascular cells adhesion molecule 1-mediated lymphocyte-endothelial cell adhesion

OBJECTIVE: To study the effect of nonsteroidal antiinflammatory drugs (NSAIDs) on the adhesion of peripheral blood lymphocytes (PBL) to activated human umbilical vein endothelial cells (HUVEC) under conditions that resemble blood flow. METHODS: Assays of adhesion of PBL to HUVEC or recombinant vascular cell adhesion molecule 1 (rVCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin were performed under continuous rotation at 37 degrees C. The phenotype of PBL subpopulations attached was characterized by flow cytometry. Lymphocytes were pretreated with different doses (5-100 microg/ml) of aceclofenac, diclofenac, indomethacin, or piroxicam or with inhibitory monoclonal antibodies (MAb) prior to the adhesion assays. The effect of NSAIDs on lymphocyte adhesion molecules was assessed by flow cytometry. To determine whether NSAIDs interfere with the affinity state of very late activation antigen 4 (VLA-4) integrin, we studied the effect of these drugs on the appearance of a beta1 activation-dependent epitope recognized by the HUTS21 MAb both on human T lymphoblasts and on synovial fluid lymphocytes (SFL). RESULTS: In the flow-resembling model, PBL-HUVEC adhesion was mainly mediated by the VLA-4/ VCAM-1 adhesion pathway. The major PBL subset attached was the CD3+, CD45RO+ memory T cell, with CD49d(high) expression. Aceclofenac, diclofenac, and indomethacin, but not piroxicam, were able to inhibit PBL adhesion to HUVEC or rVCAM-1. However, the quantitative expression of VLA-4 was not affected by treatment of PBL with any of the NSAIDs studied. On T lymphoblasts and SFL, mostly CD45RO+ cells, the expression of the beta1 activation-dependent epitope detected by HUTS21 MAb was significantly decreased by aceclofenac, diclofenac, and indomethacin. CONCLUSION: Some NSAIDs are able to inhibit the adhesion of PBL to HUVEC under conditions that resemble blood flow by interfering with the conformational change in VLA-4 that increases its affinity for VCAM-1.     

Rickettsia conorii infection enhances vascular cell adhesion molecule-1- and intercellular adhesion molecule-1-dependent mononuclear cell adherence to endothelial cells

Leukocyte adherence to the endothelium is an essential component of the inflammatory response during rickettsial infection. In vitro, Rickettsia conorii infection of endothelial cells enhances the expression of adhesive molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in a time- and dose-dependent manner. Rickettsial lipopolysaccharide does not seem to be involved, because polymyxin B does not reduce their expression. The intracellular presence of the organism and de novo host protein synthesis are required for expression of cell adhesive molecules, since rickettsial inactivation by formol and pretreatment of cells with cycloheximide inhibits an increase in expression. The contribution of interleukin-1alpha (IL-1alpha) to this endothelial adhesive phenotype was shown by inhibitory experiments 8 and 24 h after infection with IL-1 receptor antagonist and IL-1alpha blocking antibodies. Enhanced adherence of mononuclear cells to infected endothelial cells involved VCAM-1- and ICAM-1-dependent mechanisms at the late phase of the inflammatory response. This endothelial adhesive phenotype may constitute a key pathophysiologic mechanism in R. conorii-induced vascular injury.     

c-Myc or cyclin D1 mimics estrogen effects on cyclin E-Cdk2 activation and cell cycle reentry

Estrogen-induced progression through G1 phase of the cell cycle is preceded by increased expression of the G1-phase regulatory proteins c-Myc and cyclin D1. To investigate the potential contribution of these proteins to estrogen action, we derived clonal MCF-7 breast cancer cell lines in which c-Myc or cyclin D1 was expressed under the control of the metal-inducible metallothionein promoter. Inducible expression of either c-Myc or cyclin D1 was sufficient for S-phase entry in cells previously arrested in G1 phase by pretreatment with ICI 182780, a potent estrogen antagonist. c-Myc expression was not accompanied by increased cyclin D1 expression or Cdk4 activation, nor was cyclin D1 induction accompanied by increases in c-Myc. Expression of c-Myc or cyclin D1 was sufficient to activate cyclin E-Cdk2 by promoting the formation of high-molecular-weight complexes lacking the cyclin-dependent kinase inhibitor p21, as has been described, following estrogen treatment. Interestingly, this was accompanied by an association between active cyclin E-Cdk2 complexes and hyperphosphorylated p130, identifying a previously undefined role for p130 in estrogen action. These data provide evidence for distinct c-Myc and cyclin D1 pathways in estrogen-induced mitogenesis which converge on or prior to the formation of active cyclin E-Cdk2-p130 complexes and loss of inactive cyclin E-Cdk2-p21 complexes, indicating a physiologically relevant role for the cyclin E binding motifs shared by p130 and p21.     

Rat neutrophils express alpha4 and beta1 integrins and bind to vascular cell adhesion molecule-1 (VCAM-1) and mucosal addressin cell adhesion molecule-1 (MAdCAM-1)

The alpha4 integrins, which are constitutively expressed on all human leukocyte subtypes except neutrophils, interact with vascular cell adhesion molecule-1 (VCAM-1) and mucosal addressin cell adhesion molecule (MAdCAM-1) on endothelium to mediate selective recruitment of leukocyte subpopulations, other than neutrophils, to sites of inflammation. However, here we report that a different paradigm of leukocyte recruitment may exist in the rat. Flow cytometric analysis of rat neutrophils using a panel of monoclonal antibodies which recognize rat alpha4 and beta1 integrins showed consistent, low levels of expression. Although alpha4 was expressed at lower levels on neutrophils than all other rat leukocytes, this level of expression was sufficient to mediate significant levels of alpha4- and beta1-dependent neutrophil adhesion to rat and human VCAM-1, and alpha4-dependent, but beta1-independent, adhesion to human MAdCAM-1. These data suggest that rat neutrophils, unlike other species, may use alpha4 integrins to traffic to sites of inflammation in vivo.     

Circulating vascular cell adhesion molecule-1 in pre-eclampsia, gestational hypertension, and normal pregnancy: evidence of selective dysregulation of vascular cell adhesion molecule-1 homeostasis in pre-eclampsia

The potential of DNase I to increase cystic fibrosis sputum elastase activity and lung damage was evaluated. Sputum from CF patients induced little lung hemorrhage when instilled intranasally in C57BL/6 mice. However, sputum treated in vitro by the addition of 1 mg/ml bovine DNase I showed increased neutrophil elastase activity (7.97 +/- 1.56 versus 3.91 +/- 0.62 microM, p < 0.01) and induced marked lung hemorrhage in mice (bronchoalveolar lavage fluid hemoglobin = 192.8 +/- 40.7 versus 44.5 +/- 12.0 microg/ml, p < 0.01). These effects were not observed with DNase I alone in phosphate buffer and were suppressed by the human neutrophil elastase inhibitor methoxysuccinyl-alanyl-alanyl-prolyl-valine-chloromethylketone (MeOSAAPV-CMK). In vivo administration of 2.5 mg aerosolized recombinant human DNase I to patients with CF resulted in a 2.2-fold increase of sputum elastase activity within 1 h of treatment. Elastase levels returned to pre-rhDNase therapy levels 24 h after aerosol treatment. Sputum collected 1 h after rhDNase on 4 separate days from two of six patients in which elastase levels were highest, induced lung hemorrhage when instilled intranasally in mice. We conclude that DNase I therapy of patients with cystic fibrosis can acutely increase the elastase activity of sputum and also its potential to induce hemorrhage in the murine lung.     

Circulating vascular cell adhesion molecule-1 (VCAM-1) in atherosclerotic NIDDM patients

Vascular cell adhesion molecule-1 (VCAM-1) has been shown to be highly expressed in atherosclerotic lesions. Although the soluble form of VCAM-1 (sVCAM-1) is detected in human sera, the relation between the degree of atherosclerosis and serum sVCAM-1 level has not been defined. In the present study, sVCAM-1 concentrations were measured in sera from 101 Japanese NIDDM patients. The mean +/- SD serum sVCAM-1 concentration in 26 patients with symptomatic atherosclerotic vascular diseases (789 +/- 187 ng/ml) was higher than that in 75 patients without the disease (664 +/- 175 ng/ml). Among the 101 NIDDM patients, 56 had atherosclerotic change of the carotid arteries, based on the evaluation by high-resolution B-mode ultrasonography. Their sVCAM-1 level was 759 +/- 201 ng/ml, higher than that in 45 patients without any detectable atherosclerosis of the carotid arteries (619 +/- 130 ng/ml). In addition, there was a positive correlation between sVCAM-1 concentration and thickness of the intimal plus medial complex (IMT) of the carotid arteries in the NIDDM patients (r = 0.41, P < 0.0001). Multivariate regression analysis revealed significant predictors of mean IMT value to be sVCAM-1 concentration (F = 62.88, P = 0.0001) and age (F = 9.59, P = 0.0026). By contrast, sVCAM-1 concentration was not increased in nondiabetic patients with atherosclerotic change of the carotid arteries (668 +/- 191 ng/ml; n = 36) compared with those without the atherosclerotic change (632 +/- 177 ng/ml; n = 28), and there was no correlation between sVCAM-1 level and IMT of the carotid arteries in the nondiabetic subjects. These results indicate that circulating sVCAM-1 may be a marker of atherosclerotic lesions in NIDDM patients with symptomatic and asymptomatic atherosclerosis.     

Eosinophil tethering to interleukin-4-activated endothelial cells requires both P-selectin and vascular cell adhesion molecule-1

We examined the mechanisms used by eosinophils to tether and accumulate on interleukin-4 (IL-4)-stimulated human umbilical vein endothelial cells (HUVECs) under flow conditions. As previously reported, HUVECs treated for 24 hours with 20 ng/mL IL-4 had increased expression of P-selectin and vascular cell adhesion molecule-1 (VCAM-1) but not E-selectin. We found that eosinophils tethered and rolled on IL-4-stimulated HUVECs at physiologic shear stresses. Eosinophil rolling was quickly followed by firm adhesion. Treatment with either an anti-P-selectin monoclonal antibody (MoAb) or an anti-VCAM-1 MoAb decreased both eosinophil tethering and accumulation at 2 dyn/cm2. VCAM-1 interacts with 4-integrins expressed on eosinophils. We found that an anti-4-integrin MoAb also blocked eosinophil tethering and accumulation at 2 dyn/cm2. None of these MoAbs alone had an impact on eosinophil accumulation at lower shear stresses, but when either an anti-VCAM-1 or an anti-4-integrin MoAb was used in combination with an anti-P-selectin MoAb, all eosinophil tethering and accumulation on IL-4-stimulated HUVECs were blocked. This was true at both high and low shear stresses. These data show that both P-selectin and VCAM-1 are required to tether eosinophils at high shear stresses, but at low shear stresses these adhesion proteins can act independently to recruit eosinophils to IL-4-stimulated HUVECs.     

Assessment of the role of leucocyte function-associated antigen-1 in homotypic adhesion of activated B lymphocytes

In this study we investigated how T-cell-dependent stimuli, via interleukin-4 (IL-4) or CD40 ligation, influence homotypic B-cell adhesion when compared with induction by the T-cell-independent stimulus lipopolysaccharide (LPS). Using primary murine B cells, we found that T-cell-dependent stimulation led to increased aggregation as compared to that induced by LPS. The adhesion was to a large extent dependent on the adhesion molecule, lymphocyte function-associated antigen-1 (LFA-1). We found that activation of B cells with the mitogenic stimuli induced an increased avidity of LFA-1 for its ligand, intercellular adhesion molecule-1 (ICAM-1). The increase was stable and different from that induced by phorbol esters. Although adhesion was reduced using B cells from LFA-1(-/-) mice, aggregation occurred in response to T-cell-dependent stimuli. Our data suggest that adhesion of B lymphocytes is regulated in different modes. One is induced by antigen and leads to a transient conformational change of the LFA-1 molecule. Another is induced by mitogenic stimuli and leads to stable avidity increase of LFA-1, possibly via activation of cytoskeletal anchorage. A third is LFA-1 independent, of low avidity and is induced by T-cell-dependent stimuli.     

Circulating soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in patients with gastric cancer

The concentrations of the soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 45 patients with gastric cancer before treatment and their correlation with clinical, histological and routine laboratory parameters was examined. Data were collected on tumour stage at presentation, presence and sites of metastatic disease, tumour pathology, survival and results of routine laboratory tests. Serum concentrations of ICAM-1 and VCAM-1 were significantly elevated in the patients with gastric cancer in comparison with the group of healthy subjects (P < 0.00001 and P < 0.0001 respectively). Increased serum concentrations of VCAM-1 were associated with locally advanced and metastatic disease whereas ICAM-1 was significantly elevated both in local and in advanced/metastatic disease. Soluble E-cadherin and E-selectin concentrations did not show any significant elevation in gastric cancer patients. Concentrations of soluble adhesion molecules showed significant correlation with each other (except E-selectin and VCAM-1) and with alkaline phosphatase. Soluble ICAM-1 and VCAM-1 were significantly associated with an elevated total white cell count. Patients with elevated VCAM-1 had significantly poorer survival in comparison with patients with normal serum levels (P = 0.0361).     

Accessory cell function of keratinocytes for superantigens. Dependence on lymphocyte function-associated antigen-1/intercellular adhesion molecule-1 interaction

A growing body of evidence points to a role for epidermal keratinocytes as active participants in immunologic reactions. Inasmuch as certain T cell-mediated skin diseases, such as psoriasis and atopic dermatitis, are triggered by microbial infection, we asked whether multipassaged human keratinocytes could provide the costimulatory signals necessary to induce autologous T cell proliferation in response to bacterial-derived super-antigens. On exposure to IFN-gamma, keratinocytes are induced to express HLA-DR and HLA-DQ class II MHC Ag, and the lymphocyte function-associated Ag-1 counter-receptor intercellular adhesion molecule-1 (ICAM-1). This change in keratinocyte phenotype is accompanied by the ability of these cells to support T cell proliferation induced by two different bacterial-derived superantigens, staphylococcal enterotoxins A and B. Superantigen-driven proliferation in the presence of IFN-gamma-treated keratinocytes was significantly inhibited (70-90% reduction) by mAb against the LFA-1 alpha- or beta-chain or ICAM-1. Proliferation was not inhibited by mAb against the CD28 ligands BB-1 or B7, even though these keratinocytes express BB-1. In addition to previous defined roles for class II MHC Ag, stimulation of LFA-1 on the T cells by ICAM-1 on the keratinocytes also plays an important costimulatory role in this superantigen-mediated response. The accessory cell capability of keratinocytes was not unique to superantigen driven responses as PHA, as well as anti-CD3 mAb also induced vigorous T cell proliferation when IFN-gamma-treated keratinocytes were added. However, IFN-gamma-treated keratinocytes consistently failed to provoke an allogeneic response. These data demonstrate that 1) keratinocytes can serve as accessory cells for T cell proliferation using a variety of different stimuli, 2) the LFA-1/ICAM-1 interaction plays a major role in keratinocyte-mediated costimulation, and 3) previous reports in which IFN-gamma-treated keratinocytes failed to support T cell proliferation to nominal or alloantigens, may reflect impaired Ag presentation via class II MHC molecules, rather than lack of necessary costimulatory signals. These findings highlighting the accessory cell function of keratinocytes may have implications for our understanding of the pathogenesis of immunologic disorders of the skin.     

Functional association of platelet endothelial cell adhesion molecule-1 and phosphoinositide 3-kinase in human neutrophils

In this paper we show that the engagement of the platelet-endothelial cell adhesion molecule-1 (PECAM-1/CD31) up-regulates the adhesion of human neutrophils to the EA.hy926 endothelial cell line through a phosphoinositide 3-kinase (PI3K)-dependent pathway. Indeed, LY294002 and wortmannin prevented the effect of PECAM-1/CD31 cross-linking on cell adhesion, at concentrations known to inhibit PI3K without affecting other kinases. Both compounds blocked neutrophil binding to murine fibroblasts transfected with human ICAM-1, to purified ICAM-1 protein, or to fibronectin, suggesting that PECAM-1/CD31-mediated up-regulation of beta2 and beta1 integrin-mediated adhesion is PI3K-sensitive. We also provide evidence for the association of PECAM-1/CD31 to PI3K, because PI3K was detectable in neutrophil lysates after PECAM-1/CD31 cross-linking and immunoprecipitation. PECAM-1/CD31-dependent recruitment of PI3K was suggested by the finding that the serine/threonine kinase p70 S6 kinase (S6K), a signaling protein downstream of PI3K, is activated in neutrophils upon PECAM-1/CD31 cross-linking, based on the appearance of serine phosphorylation in S6K immunoprecipitates. In turn, S6K is not directly involved in the up-regulation of integrin function because rapamycin, which can inhibit S6K independent of PI3K, did not block PECAM-1/CD31-induced adhesion of neutrophils to beta1 and beta2 integrin substrates. In conclusion, PECAM-1/CD31 appears to be one of the molecules functionally coupled to PI3K, suggesting that this enzyme may represent a common pathway of integrin and adhesiveness regulation in leukocytes.     

Endothelial selectins and vascular cell adhesion molecule-1 promote hematopoietic progenitor homing to bone marrow

The adhesive mechanisms allowing hematopoietic progenitor cells (HPC) homing to the bone marrow (BM) after BM transplantation are poorly understood. We investigated the role of endothelial selectins and vascular cell adhesion molecule-1 (VCAM-1) in this process. Lethally irradiated recipient mice deficient in both P-and E-selectins (P/E-/-), reconstituted with minimal numbers (相似文献   

Antibodies to proteinase 3 mediate expression of vascular cell adhesion molecule-1 (VCAM-1)

Although much is known about the characteristics of employees who smoke cigarettes, very little is known about workers who use smokeless tobacco. The current study was designed to understand the characteristics of smokeless tobacco users in relation to their performance at work and compare them with smokers and former tobacco users. Data were collected via interviews and questionnaires from a random sample of employees working at Pacific Lumber Company (N = 146), the largest single-site lumber mill in California. A total of 63 smokeless tobacco users (21 of whom also smoked cigarettes), 43 cigarette smokers, and 40 employees who had successfully quit using tobacco (34 of whom previously used cigarettes only) provided information about their health behavior, quality of work life, and performance at work. Analyses revealed that smokeless tobacco users reported less healthful sleep patterns, drank alcohol more often, were intoxicated more often, reported less job satisfaction and organizational commitment, and reported that both chewers and smokers do not work as hard and take more breaks than do tobacco-free employees (quitters). Specific differences among chewers-only, smokers-only, smokers-and-chewers, and quitters are presented. Results suggest the organizational value of developing worksite cessation programs for smokeless tobacco users.     

Expression of vascular cell adhesion molecule-1 by vascular endothelial cells in immune and nonimmune inflammatory reactions in the skin

Expression of VCAM-1 was compared with that of E-selectin in cytokine-induced lesions and in delayed-type hypersensitivity reactions to tuberculin purified protein derivative (PPD) in pig skin. Lumenally expressed Ags were quantified by measuring localization in skin of i.v. injected (111)In-mAb 10.2C7 (anti-vascular cell adhesion molecule-1 (anti-VCAM-1), (125)I-mAb 1.2B6 (anti-E-selectin), and (99m)Tc-MOPC21 (control IgG1). Anti-VCAM-1 mAb uptake was greater following intradermal (i.d.) injection of TNF-alpha than following injection of IL-1, while the two cytokines induced similar uptake of anti-E-selectin. In immunologically naive pigs there was no detectable increase in anti-VCAM-1 after i.d. injection of PPD, although anti-E-selectin uptake was increased at 3 and 6 h. In contrast, i.d. injection of PPD in sensitized pigs led to increased uptake of both anti-VCAM-1 and anti-E-selectin at 6, 8, 24, and 48 h, each of which was significantly greater than the uptake of control IgG1 into the same lesions (each p < 0.01). Anti-TNF-alpha mAb abolished the increased uptake of anti-VCAM-1 3 and 8 h following i.d. injection of PPD in sensitized pigs and significantly inhibited uptake at 24 h (p = 0.0025), but did not significantly reduce uptake of anti-E-selectin. We conclude that in this delayed-type hypersensitivity model 1) E-selectin expression by endothelial cells follows sequential Ag nonspecific and immune-specific phases, 2) increased VCAM-1 expression by endothelial cells is only seen in sensitized animals, and 3) expression of VCAM-1 appears to be relatively more dependent on TNF-alpha than E-selectin. Differential expression of E-selectin and VCAM-1 may influence the leukocytic infiltrate during the course of nonspecific and immune-specific inflammatory reactions.