CD31/PECAM-1-driven chemokine-independent transmigration of human T lymphocytes

We assessed the relative contribution of CD31/PECAM-1 (platelet-endothelial cell adhesion molecule-1) to T lymphocyte transmigration by the use of transfected murine fibroblasts stably expressing either the human CD31/PECAM-1 or the intercellular adhesion molecule-1 (CD54/ICAM-1). Unlike CD54/ICAM-1, CD31/PECAM-1 supported migration of activated T cells in the absence of chemokines: most of the migrating lymphocytes were CD31⁺ and displayed a phenotype corresponding to the naive subpopulation (LFA-1^dull and CD45RA⁺). Migration of activated T lymphocytes through CD54/ICAM-1⁺ transfected monolayers could be induced by creating a chemotactic gradient with the chemokine monocyte chemotactic protein-1, and the migrating cells mainly displayed a memory phenotype (LFA-1^brightCD45RO⁺) under these conditions. Furthermore, we found that in transfected cells CD54/ICAM-1 is uniformly distributed along the apical surface of the cells, while CD31/PECAM-1 is concentrated at the intercellular junctions, suggesting the existence of a haptotactic gradient (i.e. a gradient of substrate- or cell-bound molecules) responsible for T cell migration. This was also confirmed by the finding that monolayers of murine fibroblasts transfected with a CD31/PECAM-1 mutant lacking the cytoplasmic domain (CD31/PECAM-1-Δcyto), which has a reduced tendency to localize at cell-cell contact areas, supported efficient adhesion but were unable to induce migration of activated T cells unless a chemotactic gradient was created. We propose that in lymphocytes, homophilic CD31/PECAM-1 adhesion may be primarily involved in transmigration of naive T cells and that its role is complementary to that of CD54/ICAM-1.     

Vascular endothelial growth factor, platelet endothelial cell adhesion molecule-1 and vascular cell adhesion molecule-1 in the follicular fluid of patients undergoing IVF.

BACKGROUND: The aim of our study was to measure concentrations of vascular endothelial growth factor (VEGF), platelet endothelial cell adhesion molecule-1 (PECAM-1) CD31 and vascular cell adhesion molecules (VCAM-1) in the follicular fluid of women treated with assisted reproduction technology to determine whether these proteins might be outcome markers. METHODS: Follicular fluid was collected from 75 patients < or =40 years undergoing oocyte retrieval procedures at our tertiary hospital during 1997 and 1998: 50 with tubal disease, 12 with endometriosis, and 13 whose partners had been diagnosed with severe oligoasthenoteratozoospermia. This retrospective analysis considered age and information about treatment and outcome for all these women who had undergone fewer than three assisted reproduction attempts. RESULTS: Nineteen women became pregnant (defined by human chorionic gonadotrophin concentrations and embryonic cardiac activity 1 month after follicular aspiration); 56 did not. Women did not differ significantly in their follicular fluid concentrations of VEGF, sCD31 and VCAM-1 according to cause of infertility, or assisted reproduction outcome, or age. Follicular fluid concentrations of VEGF were significantly correlated with the number of gonadotrophin ampoules administered (P < 0.012), and follicular fluid concentrations of sVCAM-1 with the fertilization rate (P < 0.01). Follicular fluid concentrations of VEGF and sVCAM-1 were also correlated (P < 0.007). CONCLUSIONS: Our results do not suggest that VEGF, CD31, or sVCAM-1 in follicular fluid predict assisted reproduction outcome, especially among patients < or =40 years old. The correlation of a high fertilization rate and sVCAM-1 in follicular fluid suggests that sVCAM-1 might be a marker of fertilization.     

Transendothelial migration and trafficking of leukocytes in LFA-1-deficient mice

The leukocyte integrin LFA-1 plays an important role in leukocyte trafficking and the immune response. Using LFA-1-deficient mice, we demonstrate that LFA-1 regulates the trafficking of lymphocytes to peripheral lymph nodes, and, to a lesser degree, to mesenteric lymphnodes and acute inflammatory sites. LFA-1, either because of its role in initial adhesion and/or the passage of leukocytes across endothelial cells, plays a vital role in T lymphocyte and neutrophil transendothelial migration. Neutrophils and activated T lymphocytes from LFA-1-deficient mice were unable to cross endothelial cell monolayers in response to a chemokine gradient, whereas wild-type (WT) T lymphocytes and neutrophils were capable of migration. By contrast, LFA-1-deficient T lymphocytes displayed normal chemotaxis to the same chemokine. Our studies with LFA-1-deficient monocytes indicate that LFA-1 acts in concert with complement receptor 3 to mediate transendothelial migration of these cells, as anti-CD18 monoclonal antibodies (mAb) blocked both WT and LFA-1-deficient monocyte transendothelial migration, whereas anti-CD11b mAb preferentially blocked transendothelial migration of LFA-1-deficient monocytes. Finally, whereas anti-CD31 mAb blocked WT monocyte and neutrophil transendothelial cell migration they did not block LFA-1-deficient monocyte and neutrophil transendothelial migration.     

Platelet-endothelial cell adhesion molecule-1 (PECAM-1/CD31) tyrosine phosphorylation state changes during vasculogenesis in the murine conceptus.

Vasculogenesis, the differentiation of mesodermal cells to angioblasts and the subsequent formation of blood islands and blood vessels by angioblasts in the conceptus, is a dynamic process modulated, in part, by cell-extracellular matrix and cell-cell interactions in the presence of a variety of growth factors and morphogens. In this report we demonstrate differential tyrosine phosphorylation of platelet-endothelial cell adhesion molecule-1 (PECAM-1) during the formation of blood islands and vessels from clusters of extraembryonic and embryonic angioblasts in the murine conceptus. In addition, we identify the phosphorylation of a particular tyrosine residue in the PECAM-1 cytoplasmic domain, Tyr686, which has the potential of mediating binding to Src homology 2 domain-containing proteins, affecting PECAM-1 cellular localization and endothelial cell migration.     

Sialomucin CD43 regulates T helper type 17 cell intercellular adhesion molecule 1 dependent adhesion,apical migration and transendothelial migration

T helper type 17 lymphocytes (Th17 cells) infiltrate the central nervous system (CNS), induce inflammation and demyelination and play a pivotal role in the pathogenesis of multiple sclerosis. Sialomucin CD43 is highly expressed in Th17 cells and mediates adhesion to endothelial selectin (E-selectin), an initiating step in Th17 cell recruitment to sites of inflammation. CD43^−/− mice have impaired Th17 cell recruitment to the CNS and are protected from experimental autoimmune encephalomyelitis (EAE), the mouse model of multiple sclerosis. However, E-selectin is dispensable for the development of EAE, in contrast to intercellular and vascular cell adhesion molecules (ICAM-1 and VCAM-1). We report that CD43^−/− mice have decreased demyelination and T-cell infiltration, but similar up-regulation of ICAM-1 and VCAM-1 in the spinal cord, compared with wild-type (WT) mice, at the initiation of EAE. CD43^−/− Th17 cells have impaired adhesion to ICAM-1 under flow conditions in vitro, despite having similar expression of LFA-1, the main T-cell ligand for ICAM-1, as WT Th17 cells. Regardless of the route of integrin activation, CD43^−/− Th17 cell firm arrest on ICAM-1 was comparable to that of WT Th17 cells, but CD43^−/− Th17 cells failed to optimally apically migrate on immobilized ICAM-1-coated coverslips and endothelial cells, and to transmigrate under shear flow conditions in an ICAM-1-dependent manner. Collectively, these findings unveil novel roles for CD43, facilitating adhesion of Th17 cells to ICAM-1 and modulating apical and transendothelial migration, as mechanisms potentially responsible for Th17 cell recruitment to sites of inflammation such as the CNS.     

Murine platelet endothelial cell adhesion molecule (PECAM-1)/CD31 modulates β2 integrins on lymphokine-activated killer cells

Lymphokine-activated killer (LAK) cells are able to colonize sites of tumor lesions in mouse and man. The molecular mechanisms of homing in on tumors are largely unknown. However, before LAK cells can reach the tumor, they must adhere to the vascular endothelia within the lesion and then extravasate. We developed a novel mAb, EA-3, which recognizes the murine homologue of the human adhesion molecule CD31. It is present on a subpopulation of murine LAK cells and all endothelial cells. CD31 was also involved in the adhesion of LAK cells to endothelium. Since CD31 can initiate integrin activation by inside-out signaling after binding to its ligand, EA-3 was used to minimic this in adhesion assays. It induces modifications in the β₂ integrin LFA-1, leading to increased binding capacities of the cells to endothelium. In contrast, β₁ integrins and RGD-binding integrins were not affected. These results suggest that expression of CD31 might confer adhesive advantages for LAK cells prone to tumor infiltration.     

Changes in expression of the cell adhesion molecule PECAM-1 (CD31) during differentiation of human leukemic cell lines

Abstract: PECAM-1, a member of the immunoglobulin gene superfamily, is widely distributed on cells of the vascular system, and mediates cellular interactions through both homotypic and heterotypic adhesive mechanisms. Previous studies have demonstrated that PECAM-1 is initially expressed at high levels on CD34⁺ multipotential progenitors in the bone marrow, but is subsequently downregulated in more committed precursors of all lineages. Interestingly, although PECAM-1 expression is high on circulating monocytes and neutrophils, little is known about the upregulation of PECAM-1 expression during terminal myelomonocytic differentiation. We have further characterized this process by examining PECAM-1 expression during chemically-induced differentiation of the U937, HL-60 and HEL cell lines. Quantitative Western blot analysis of cellular lysates indicated that PECAM-1 expression could be upregulated in U937 and HL-60 cells by phorbol esters or dimethyl sulfoxide. Northern blot analysis showed that PECAM-1 mRNA levels appeared to increase in parallel with that of PECAM-1 protein. We also observed a marked difference in the apparent molecular mass of PECAM-1 that was lineage-specific, both in differentiated leukemic cell lines and in their corresponding leukocyte population. Immunofluorescence localization indicated that the cellular distribution of PECAM-1 in U937 and HL-60 cells was similar to that of their normal circulating counterparts, and that the pattern of distribution again displayed lineage fidelity. The ability to induce the expression of PECAM-1 molecules having different glycosylation and surface expression patterns may prove useful for further elucidation of the role of PECAM-1 in hematopoiesis, as well as studies of the cell lineage-specific modulation of PECAM-1 function.     

Increased adhesion to vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 of eosinophils from patients with asthma

Adhesion of peripheral blood eosinophil and neutrophil granulocytes to the endothelial cell adherence receptors E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 has been measured. The study included patients with allergic rhinitis, patients with mild allergic and nonallergic asthma, and healthy individuals; 10 persons were in each group. In addition, assay of eosinophil and neutrophil cell surface expression of the receptor complex CD11b/CD18 was performed. Increased eosinophil adhesion to vascular cell adhesion molecule-1 (p < 0.05) and intercellular adhesion molecule-1 (p < 0.05) was demonstrated in the patients with a more labile asthma, that is, a peak expiratory flow rate variability of more than 10%, suggesting a relationship to the degree of ongoing inflammation in the airways of the patients. The increased eosinophil adhesion was most probably due to a functional upregulation of the CD11b/CD18 and very late activation antigen-4 receptors, because the number of receptors measured as cell surface expression was unaltered. The increased eosinophil adhesion in the patients with high peak expiratory flow rate variability appeared independent of atopy. The increased adhesion was not entirely specific to the eosinophils, because neutrophils from patients with a peak expiratory flow rate variability of more than 10% also demonstrated increased adhesion to intercellular adhesion molecule-1 (p < 0.05) when compared with neutrophils from the patients with low peak expiratory flow rate variability. In conclusion, the demonstrated priming of eosinophil adhesion to vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 might be one contributing mechanism behind the selective accumulation of eosinophils in the lung tissue of patients with asthma. (J ALLERGY CLIN IMMUNOL 1995;96:941-50.)     

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.     

Costimulation of naive human CD4 T cells through intercellular adhesion molecule-1 promotes differentiation to a memory phenotype that is not strictly the result of multiple rounds of cell division

The process by which naive T cells become activated, differentiate into effector cells and ultimately generate long-lived memory cells is dependent upon a number of factors, including the costimulatory signals received by the T cell. To best understand the multiple events involved, it is important to understand the potential contributions by individual signalling proteins using both in vitro and in vivo studies. Here, the potential for costimulation through intercellular adhesion molecule-1 (ICAM-1; CD54), resident on the surface of naive human T cells, to influence differentiation was investigated. Costimulation of naive T cells through ICAM-1 resulted in expansive cell division, high interleukin-2 production, and protection from apoptosis. Prolonged culture led to outgrowth of a subpopulation of cells with a highly differentiated CD45RA- CD11a(hi) CD27- phenotype. In this respect, costimulation through ICAM-1 was similar to costimulation through CD28 and different from costimulation through leucocyte function-associated antigen-1. The CD45RA- CD11a(hi) CD27- cells responded to suboptimal stimulation through the T-cell receptor alone with a more robust proliferative response compared with naive cells from the same subject. These cells also secreted higher levels of T helper type 1 cytokines in response to lower levels of stimulation than their naive counterparts. The surface phenotype and more sensitive response characteristics suggest the creation of a memory T-cell subpopulation as a result of costimulation through ICAM-1. Finally, generation of this memory population was the result of specific costimulatory signals, and not merely because of a high number of cell divisions. These data reveal a new role for resident ICAM-1 to influence the differentiation of naive T cells.     

LAIR-1/LAIR-2(CD305/CD306)推定配体分布的研究

目的：研究LAIR-1（CD305）及LAIR-2（CD306）推定配体在多种细胞系上的分布，为鉴定LAIR-1／LAIR-2推定配体提供了实验依据。方法：建立稳定表达LAIR-1-Fc和LAIR-2-Fc融合蛋白的细胞系。以纯化的融合蛋白进行活细胞免疫荧光染色，用流式细胞仪检测LAIR-1及LAIR-2推定配体在多种细胞系膜表面的表达，并比较LAIR-1和LAIR-2推定配体的分布及可能结合的位点。结果：LAIR-1推定配体及LAIR-2推定配体均在人羊膜来源的上皮细胞系WISH上高表达，在人黑色素瘤细胞系C32、人胚肾上皮细胞系293T及人脐静脉内皮细胞系ECV304上有一定程度的表达。LAIR-1-Fc和LAIR-2-Fc融合蛋白与推定配体的结合，可分别被可同时识别LAIR-2和LAIR-1的单克隆抗体（mAb）FMU-LAIR-2．2和FMU-LAIR-2．1阻断。结论：LAIR-1推定配体及LAIR-2推定配体的分布基本一致，主要表达于WISH、C32、293T和ECV304细胞系。LAIR-1和LAIR-2可能拥有共同的配体。     

Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression and function on cultured human glomerular epithelial cells.

Glomerular epithelial cells are involved in extracapillary inflammation (crescents) but the mechanisms of this extracapillary accumulation of macrophages, epithelial cells and occasional lymphocytes are unknown. Human glomerular parietal epithelial cells express ICAM-1 and VCAM-1 on immunohistological stains of renal biopsies. We studied the expression of these cell adhesion molecules on cultured human glomerular epithelial cells (HGEC), their regulation by pro-inflammatory cytokines, and their role in mediating the adhesion of concanavalin A (Con A)-activated peripheral blood mononuclear cells. Human glomerular epithelial cells in culture constitutively express ICAM-1 and VCAM-1. The expression of ICAM-1 was not significantly altered by tumour necrosis factor-alpha (TNF-alpha) (P = 0.32), IL-1 beta (P = 0.24), interferon-gamma (IFN-gamma) (P = 0.66) or IL-4 (P = 0.85). VCAM-1 expression was increased by all four cytokines, but only significantly so by IL-4 (P = 0.0001). Con A-stimulated, monocyte-depleted peripheral blood lymphocytes bound to human glomerular epithelial cells, median 28.9% (range 14.5-37.9%). This adherence was significantly inhibited by anti-ICAM-1 (P = 0.03) and anti-LFA-1 (P = 0.02), but not by anti-VCAM-1 (P = 0.13) or by antibody to von Willebrand factor (P = NS). The interaction between ICAM-1 on HGEC and LFA-1 on mononuclear cells may be important in the pathogenesis of extracapillary inflammation in glomerulonephritis.     

Up-regulation of intercellular adhesion molecule-1 (ICAM-1), endothelial leucocyte adhesion molecule-1 (ELAM-1) and class II MHC molecules on pulmonary artery endothelial cells by antibodies against U1-ribonucleoprotein

In order to elucidate the pathogenic role(s) of autoantibodies in connective tissue disease (CTD), we examined whether autoantibodies against U1-ribonucleoprotein (RNP) and double-stranded (ds) DNA can up-regulate ICAM-1, ELAM-1 and class I and II MHC molecule expression on pulmonary artery endothelial cells (HPAEC). ICAM-1, ELAM-1 and class II MHC molecule expression on HPAEC cultured in the presence of anti-U1-RNP-containing and anti-dsDNA-containing IgG from CTD patients was up-regulated significantly in comparison with that on HPAEC cultured with IgG from normal healthy volunteers. Affinity chromatographic enrichment and depletion of the anti-U1-RNP antibody content of anti-U1-RNP-containing IgG confirmed that the anti-U1-RNP antibody did up-regulate ICAM-1, ELAM-1 and class II MHC molecule expression. The finding that an IgG F(ab')2-purified anti-U1-RNP antibody also up-regulated expression of these molecules may indicate that mechanisms other than Fc receptor-mediated stimulation are involved. These in vitro findings suggest that autoantibodies against U1-RNP and dsDNA play important roles in the immunopathological processes leading to the proliferative pulmonary arterial vasculopathy observed in CTD patients with pulmonary hypertension by up-regulating adhesion and class II MHC molecule expression on endothelial cells.     

神经调节因子Neuregulin-1(Nrg1)调节U87-MG细胞的黏附分子L1表达及促迁移作用

目的研究神经调节因子Neuregulin-1(Nrg1)对人胶质母细胞瘤U87-MG细胞中细胞黏附分子L1表达及细胞迁移的影响。方法给予U87-MG细胞重组Nrg1α(rNrg1α,2.5 nmol/L)24和48 h,RT-PCR观察L1 mRNA表达;给予细胞rNrg1α或rNrg1β(2.5 nmol/L)48 h,Western blot检测L1蛋白水平。用Nrg1 siRNA处理细胞,Western blot观察L1蛋白水平,用细胞划伤实验观察细胞迁移。结果 Nrg1α可促进L1 mRNA表达;与0 nmol/L组相比,Nrg1α及Nrg1β(2.5 nmol/L)均可显著增加L1蛋白水平(P<0.01,P<0.05)。与对照siRNA相比,Nrg1 siRNA明显降低Nrg1表达,并伴有L1表达下降。Nrg1 siRNA处理细胞划伤16 h,划伤边缘细胞Nrg1α、Nrg1β及L1荧光信号降低,细胞迁移减弱。结论 Nrg1可调节U87-MG细胞L1表达,其参与细胞迁移可能与提高L1表达有关。     

Correlation between recent thymic emigrants and CD31+ (PECAM-1) CD4+ T cells in normal individuals during aging and in lymphopenic children

CD31(+)CD45RA(+)RO(-) lymphocytes contain high numbers of T cell receptor circle (TREC)-bearing T cells; however, the correlation between CD31(+)CD4(+) lymphocytes and TREC during aging and under lymphopenic conditions has not yet been sufficiently investigated. We analyzed TREC, telomere length and telomerase activity within sorted CD31(+) and CD31(-) CD4(+) lymphocytes in healthy individuals from birth to old age. Sorted CD31(+)CD45RA(+)RO(-) naive CD4(+) lymphocytes contained high TREC numbers, whereas CD31(+)CD45RA(-)RO(+) cells (comprising < or =5% of CD4(+) cells during aging) did not contain TREC. CD31(+) overall CD4(+) cells remained TREC rich despite an age-related tenfold reduction from neonatal (100 : 1000) to old age (10 : 1000). Besides a high TREC content, CD31(+)CD45RA(+)RO(-)CD4(+) cells exhibited significantly longer telomeres and higher telomerase activity than CD31(-)CD45RA(+)RO(-)CD4(+) cells, suggesting that CD31(+)CD45RA(+)RO(-)CD4(+) cells represent a distinct population of naive T cells with particularly low replicative history. To analyze the value of CD31 in lymphopenic conditions, we investigated six children after allogeneic hematopoietic stem cell transplantation (HSCT). Reemerging overall CD4(+) as well as naive CD45RA(+)RO(-)CD4(+) cells predominantly expressed CD31 and correlated well with the recurrence of TREC 5-12 months after HSCT. Irrespective of limitations in the elderly, CD31 is an appropriate marker to monitor TREC-rich lymphocytes essentially in lymphopenic children after HSCT.     

Roles of alpha(4) integrins/VCAM-1 and LFA-1/ICAM-1 in the binding and transendothelial migration of T lymphocytes and T lymphoblasts across high endothelial venules

Several cell adhesion molecules that mediate the binding of lymphocytes to high endothelial venules (HEV) from flowing blood have been identified but the regulation of lymphocyte migration across the HEV wall into the lymph node (LN) is far from understood. In this study we have used an in vitro model of lymphocyte migration across HEV, and analysed the roles of two integrins in the binding and transendothelial migration of T lymphocytes and T lymphoblasts. The adhesion of T lymphocytes to high endothelial cells (HEC) cultured from rat LN HEV differed from that of T lymphoblasts since the percentage of T lymphoblasts that adhered and transmigrated was higher and was not increased by IFN-gamma pretreatment of HEC. Antibodies to alpha(4) integrins, VCAM-1 or LFA-1 maximally inhibited T lymphocyte adhesion by 40-50%, whereas antibodies to ICAM-1 were less effective (<20% inhibition). The effects of alpha(4) integrin and LFA-1 antibodies were additive, giving >90% inhibition. T lymphocytes which adhered in the presence of LFA-1 antibody showed reduced levels of transmigration and, in the presence of alpha(4) integrin antibody, slightly increased transmigration. Antibodies to alpha(4) integrins, VCAM-1, LFA-1 or ICAM-1 had little effect on T lymphoblast adhesion (maxima of 10-30% inhibition) and T lymphoblasts transmigrated normally in the presence of either alpha(4) integrin or LFA-1 antibodies. However, the effects of alpha(4) integrin and LFA-1 antibodies on T lymphoblast adhesion were synergistic, giving >90% inhibition of adhesion. These results suggest that the majority of T lymphoblasts use either alpha(4) integrins or LFA-1 to bind and transmigrate HEV, and the roles of these integrins on activated T cells are overlapping and redundant. In contrast, either integrin supports half-maximal binding of unactivated T lymphocytes to the surface of HEV and LFA-1 makes a larger contribution than alpha(4) integrins to transendothelial migration.     

Decreased expression of intercellular adhesion molecule-1 (ICAM-1) and urokinase-type plasminogen activator receptor (uPAR) is associated with tumor cell spreading in vivo

The development of an effective antitumor immune response to control tumor growth is influenced by the tumor cell itself and/or by the tumor microenvironment. Tumor invasion and tumor cell spreading require a finely tuned regulation of the formation and loosening of adhesive contacts of tumor cells with the extracellular matrix (ECM). In our laboratory, a rat tumor cell line derived from a spontaneous rat sarcoma revealed, by flow cytometry, a high frequency of intercellular adhesion molecule-1 (ICAM-1, 70.1 ± 8.7%) and urokinase-type plaminogen activator receptor (uPAR, 51.2 ± 5.2%) positive cells, while a weak expression of MHC class II (IA, 2.2±0.2% and IE, 17.4±3.7%) and B7 (12.1±2.2%) antigens was detected. In our tumor experimental model, after implantation of tumor cells, visible tumor masses were present at days 5–7 with a relatively fast tumor growth until day 15 (progressive phase) followed by a suppression of the tumor growth (regressive phase). Here we present data that correlates a significant decrease in the frequency of ICAM-1 and uPAR expressing tumor cells with the appearance of tumor cells in sites distant from that of the primary tumor. In addition we describe the development of a cellular immune response which controls the tumor progression and is associated with an increase in the expression of major histocompatibility complex (MHC) class II IA antigen during tumor development. The histological examination at tumor progressive and regressive time points revealed the relevant presence of polymorphonuclear neutrophils (PMNs) evidencing colliquative necrosis in tumor growth areas. Taken together, these results support the idea that the balance between adhesive interactions, proteolytic activity and tumorigenicity may lead to a tumor invasive phenotype. This revised version was published online in July 2006 with corrections to the Cover Date.     

OX-LDL诱导内皮细胞条件培养液对内皮细胞VCAM-1和 ICAM-1的影响

目的探讨受损内皮细胞的自分泌和旁分泌对内皮细胞自身的影响。方法利用正常内皮细胞条件培养液和用氧化型低密度脂蛋白(OX-LDL)诱导内皮细胞的条件培养液分别作用于正常内皮细胞和受损内皮细胞,用酶联免疫细胞化学法检测血管内皮细胞黏附分子-1(VCAM-1)和细胞间黏附分子-1(ICAM-1)表达的变化。结果正常内皮细胞的条件培养液和OX-LDL诱导的内皮细胞条件培养液对正常内皮细胞VCAM-1和ICAM-1的表达作用不明显(P>0.05),而对受损内皮细胞VCAM-1和ICAM-1的表达具有明显的下调作用(P<0.01)。结论正常和受到氧化损伤的内皮细胞的自分泌和旁分泌作用对正常内皮细胞黏附分子没有影响,而对受损内皮细胞黏附分子有下调作用,说明内皮细胞可通过下调黏附分子的表达来实现自身的抗损伤作用。     

Kupffer cell-mediated cytotoxicity against hepatoma cells occurs through production of nitric oxide and adhesion via ICAM-1/CD18

Rat Kupffer cell (KC)-mediated cytotoxicity against both thesyngeneic hepatoma cell line AH70 and hepatocytes was evaluatedby changes in mitochondrial function, and the possible roleof ICAM-1/CD18 in the interaction between the cells was studied.Rhodamine 123 fluorescence, a marker of the mitochondrial membranepotential, decreased in AH70 cells after co-culture with KC,while that in hepatocytes was unchanged by co-culture. Thisdecrease was blocked by anti-ICAM-1, anti-CD18 and the Inhibitionof nitric oxide synthesis. Cytometric studies demonstrated thatICAM-1 expression on AH70 cells increased after addition ofIFN-, IL-1ß, tumor necrosis factor (TNF)- or KC, whilein hepatocytes ICAM-1 was not increased. Anti-ICAM-1 pretreatmentinhibited the increase in ICAM-1 expression and the decreasein rhodamine 123 fluorescence on AH70 cells after co-culturewith KC. CD18 on KC was increased only after co-culture withAH70. TNF- but not IFN- was detected in the supernatant of co-culturebetween KC and AH70 cells, and this production was partiallyinhibited by anti-ICAM-1 and anti-CD18. The activity of Induciblenitric oxide synthase in Kupffer cells and the levels of nitritesand nitrates in the co-culture supernatant increased over time,and this increase was attenuated either by addition of NO synthesisinhibitors, anti-ICAM-1 or anti-CD18. These results indicatethat the rat KC causes mitochondrial dysfunction in cancer cellsvia the production of NO and cell-to-cell adhesion via ICAM-1/CD18has an Important role in this cytotoxic process.     

Activated leukocyte cell adhesion molecule (ALCAM) is a marker of recurrence and promotes cell migration,invasion, and metastasis in early‐stage endometrioid endometrial cancer

Endometrial cancer is the most common gynaecological cancer in western countries, being the most common subtype of endometrioid tumours. Most patients are diagnosed at an early stage and present an excellent prognosis. However, a number of those continue to suffer recurrence, without means of identification by risk classification systems. Thus, finding a reliable marker to predict recurrence becomes an important unmet clinical issue. ALCAM is a cell–cell adhesion molecule and member of the immunoglobulin superfamily that has been associated with the genesis of many cancers. Here, we first determined the value of ALCAM as a marker of recurrence in endometrioid endometrial cancer by conducting a retrospective multicentre study of 174 primary tumours. In early‐stage patients (N = 134), recurrence‐free survival was poorer in patients with ALCAM‐positive compared to ALCAM‐negative tumours (HR 4.237; 95% CI 1.01–17.76). This difference was more significant in patients with early‐stage moderately–poorly differentiated tumours (HR 9.259; 95% CI 2.12–53.47). In multivariate analysis, ALCAM positivity was an independent prognostic factor in early‐stage disease (HR 6.027; 95% CI 1.41–25.74). Then we demonstrated in vitro a role for ALCAM in cell migration and invasion by using a loss‐of‐function model in two endometrial cancer cell lines. ALCAM depletion resulted in a reduced primary tumour size and reduced metastatic local spread in an orthotopic murine model. Gene expression analysis of ALCAM‐depleted cell lines pointed to motility, invasiveness, cellular assembly, and organization as the most deregulated functions. Finally, we assessed some of the downstream effector genes that are involved in ALCAM‐mediated cell migration; specifically FLNB, TXNRD1, and LAMC2 were validated at the mRNA and protein level. In conclusion, our results highlight the potential of ALCAM as a recurrent biomarker in early‐stage endometrioid endometrial cancer and point to ALCAM as an important molecule in endometrial cancer dissemination by regulating cell migration, invasion, and metastasis. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.