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E C Butcher

Publications and source records attributed to E C Butcher.

At least 19 recordsLinked to original sources
PubMed1992

Comparison of L-selectin and E-selectin ligand specificities: the L-selectin can bind the E-selectin ligands sialyl Le(x) and sialyl Le(a).

The L- and E-selectins are leukocyte and endothelial cell surface molecules which mediate leukocyte-endothelial cell adhesion by interacting with carbohydrate ligands. In the present study we find that L-selectin, like E-selectin, can interact with synthetic neoglycoproteins containing Sialyl Le(x) (Neu5Ac alpha 2-3Gal beta 1-4[Fuc alpha 1-3]GlcNAc beta-R), or Sialyl Le(a) (Neu5Ac-alpha 2-3Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta-R). Additionally, both the E-selectin and L-selectin can bind the peripheral lymph node addressin, a high endothelial venule ligand for L-selectin. Despite overlapping interactions, the L- and E-selectins discriminate between their native ligands. The peripheral lymph node addressin is a preferential ligand for L-selectin; and furthermore, L-selectin expressing cells do not interact detectably with the cutaneous lymphocyte antigen, a native glycoprotein ligand for E-selectin found on a subset of lymphocytes associated with the skin.

Animals↗
PubMed1992

Antibody against the Leu-CAM beta-chain (CD18) promotes both LFA-1- and CR3-dependent adhesion events.

The Leukocytic cell-adhesion molecule (beta 2 integrin) family of adhesion molecules play a key role in the intercellular adhesive interactions necessary for normal immune cell function. In this study, we report an antibody that recognizes an epitope on the Leukocytic cell-adhesion molecule common beta-chain (CD18) and promotes both lymphocyte function-associated Ag-1- and CR3-dependent adhesion events. The antibody recognizes a temperature-sensitive epitope that is not dependent on the presence of divalent cations. It is proposed that antibody binding promotes a conformational change in both lymphocyte function-associated Ag-1 and CR3, which may mimic a natural activation mechanism, resulting in increased cellular adhesion.

Antibodies, Monoclonal↗
PubMed1992

H-CAM expression in the human nervous system: evidence for a role in diverse glial interactions.

H-CAM (CD44/Hermes antigen) is an 85-95 kDa widely-distributed cell surface adhesion molecule that participates in diverse cellular interactions. It is an important cell surface receptor of hyaluronate, and has been implicated in the binding of circulating lymphocytes of endothelial cells in the process of lymphocyte homing. Here we define the immunohistological distribution of H-CAM in the human nervous system as a means of assessing its possible participation in nervous system ontogeny and function. H-CAM is widely expressed in human CNS white matter by subsets of glial cells, and within the neuropil of several grey matter structures. Neurons appear uniformly negative. H-CAM+ cells and processes are first detected at 20 weeks gestation in a diffuse subependymal pattern, and staining of the anchoring processes but not the cortical extensions of radial glia is seen by 24 weeks. Beginning at 26 weeks, H-CAM+ astrocytes also demarcate fascicles of axons in developing white matter tracts, becoming diffusely distributed in all CNS white matter by full term gestation. In the mature CNS, fibrous and subpial astrocytes, glial outlines within the glomeruli of the cerebellar granule cell layer, Bergmann glia, and extraneuronal grey matter matrix in certain locations are H-CAM+. In reactive gliosis occurring in foetal and developed brains, H-CAM is strongly and uniformly expressed by GFAP+ astroglial cells. In the PNS, dorsal roots express substantially higher levels of H-CAM than ventral roots, and there is an accompanying inverse staining pattern displayed by weakly immunoreactive posterior horns and positive anterior horns. Also, there is an abrupt cessation of H-CAM expression at the junction of the central and peripheral segments of cranial nerves. These findings indicate the dynamic regulation of H-CAM expression in the developing human nervous system, and suggest the hyaluronate-binding activity and potentially other cell-cell or cell-matrix adhesive functions of H-CAM may play an important role in development of the nervous system.

Aged↗
PubMed1992

Role of integrin alpha 4 beta 7/alpha 4 beta P in lymphocyte adherence to fibronectin and VCAM-1 and in homotypic cell clustering.

Integrins are heterodimeric cell surface proteins that mediate both cell-cell and cell-extracellular matrix interactions. We and others recently identified cDNAs encoding a novel integrin beta subunit, beta 7, in lymphocytes. We have now detected beta 7 mRNA in mouse TK-1 T lymphoma cells, which are known to express the putative Peyer's patch homing receptor alpha 4 beta P. We used an anti-peptide antiserum and a novel mAb against the beta 7 subunit to show that TK-1 cells express beta 7 as the only subunit associated with alpha 4. We conclude that beta 7 and beta P are identical. We also show that activated peripheral blood T cells express alpha 4 beta 7. We studied the function of alpha 4 beta 7/alpha 4 beta P in TK-1 cells, which do not express very late antigen (VLA)-4 (alpha 4 beta 1). Cells adhered to intact fibronectin and to a fibronectin fragment containing the CS-1 region, but not to a fragment containing the RGD sequence. Adhesion to fibronectin was inhibited by antibodies to alpha 4, suggesting that alpha 4 beta 7 is a fibronectin receptor. We confirmed that alpha 4 beta 7 binds to the CS-1 region of fibronectin using affinity chromatography. TK-1 cell adhesion to the vascular cell adhesion molecule VCAM-1 was also inhibited by antibodies to alpha 4, implying that alpha 4 beta 7 also plays a role in the adherence of lymphocytes to endothelial cells. TK-1 cell binding to fibronectin and VCAM-1 is markedly increased by brief PMA stimulation. We also found that mAbs against alpha 4 and beta 7 induce homotypic clustering of TK-1 cells. Taken together these results suggest that alpha 4 beta 7/alpha 4 beta P recognizes some or all of the same widely distributed ligands recognized by VLA-4 (alpha 4 beta 1) and that the role of alpha 4 beta 7/alpha 4 beta P may not be restricted to lymphocyte homing.

Amino Acid Sequence↗
PubMed1992

Physiological and molecular mechanisms of lymphocyte homing.

The lymphoid system is functionally compartmentalized in vivo into discrete primary, secondary, and tertiary lymphoid organs. Primary lymphoid tissues--the bone marrow and thymus--are responsible for the production of mature "virgin" lymphocytes. Secondary lymphoid tissues--lymph nodes, the spleen, and gut-associated lymphoid tissues--are specialized for the accumulation and presentation of antigen to both virgin and memory lymphocyte subsets. The remainder of the body's tissues may be considered "tertiary" lymphoid tissues, in that they normally contain only a few lymphoid elements, but in the setting of inflammation can be induced to recruit unique subsets of primarily memory lymphocytes. Each lymphoid tissue is further subdivided into discrete microenvironments, each characterized by a distinct complement of lymphocyte subsets and stromal cells. Lymphocyte homing comprises the physiologic processes by which lymphocytes seek out and localize to particular tissues and to specific microenvironments therein. Homing mechanisms play a major role in the maintenance of these specialized microenvironments and are critical for the dispersal and targeting of naive and memory lymphocyte populations that are required for effective immune surveillance. Here, we provide a brief overview of mechanisms thought to control the homing of lymphocyte populations in vivo, focusing in particular on the adhesive interactions involved in lymphocyte-endothelial cell recognition and in the selective extravasation of lymphocyte populations into secondary and tertiary lymphoid tissues.

Animals↗
PubMed1992

L-selectin function is required for beta 2-integrin-mediated neutrophil adhesion at physiological shear rates in vivo.

In vivo interactions between neutrophils and endothelial cells (EC) follow a multistep process involving two distinct neutrophil adhesion receptors. L-selectin, constitutively functional on resting neutrophils, mediates an activation-independent primary interaction resulting in rolling along the venular wall. Subsequent activation of rolling neutrophils induces upregulation and functional activation of beta 2-integrins (CD11/CD18) leading to firm attachment. Based on previous findings we hypothesized that, under shear force, rolling may be essential for successful neutrophil-EC recognition. Here we report results of our studies of human neutrophil behavior in interleukin (IL)-1-activated rabbit mesentery venules, an interaction that requires both L-selectin and beta 2-integrins. Rolling of human neutrophils is L-selection mediated; it was strongly reduced by monoclonal antibody inhibition or enzymatic removal of L-selectin. Furthermore, activation induced L-selectin shedding and, in a dose- and time-dependent fashion, rendered neutrophils unable to recognize inflamed EC despite expression of active beta 2-integrins, which promoted adhesion in vitro. Neutrophils activated for 5 min or longer lost most of their ability to roll. However, 1-3 min after activation, rolling was reduced (not abolished), and cells that were still able to roll displayed a significant tendency for a CD18-dependent transition from rolling to sticking. The whole sequence of events, rolling, sticking, and transendothelial migration, could be observed if an extravascular chemotactic stimulus was applied by superfusing mesenteries with leukotriene B4. Under such conditions, sticking and emigration was blocked when rolling was inhibited by enzymatic removal of L-selectin. Our results indicate that primary neutrophil interaction with inflamed EC through the L-selectin is a prerequisite for neutrophil function at physiological shear rates in vivo.

Antibodies, Monoclonal↗
PubMed1991

The cutaneous lymphocyte antigen is a skin lymphocyte homing receptor for the vascular lectin endothelial cell-leukocyte adhesion molecule 1.

A skin-associated population of memory T lymphocytes, defined by expression of the cutaneous lymphocyte antigen (CLA), binds selectively and avidly to the vascular lectin endothelial cell-leukocyte adhesion molecule 1 (ELAM-1), an interaction that may be involved in targeting of CLA+ T cells to cutaneous sites of chronic inflammation. Here we present evidence that CLA itself is the (or a) lymphocyte homing receptor for ELAM-1. Antigen isolated with anti-CLA monoclonal antibody HECA-452 from human tonsillar lysates avidly binds ELAM-1 transfected mouse cells. Anti-CLA antibody blocks T lymphocyte binding to ELAM-1 transfectants. HECA-452 and ELAM-1 binding to lymphocytes or to isolated tonsillar HECA-452 antigen is abrogated by neuraminidase treatment implying a prominent role for sialic acid in CLA structure and function. The dominant form of CLA on T cells is immunologically distinct from the major neutrophil ELAM-1 ligand, the sialyl Lewis x (sLex) antigen (NeuAc alpha 2-3Gal beta 1-4[Fuc alpha 1-3]GlcNAc), which is absent, weakly expressed, or masked on T cells. However, neuraminidase treatment of CLA+ T cells, but not of CLA- T cells, reveals Lewis x (CD15) structures. In combination with the known requirement for terminal NeuAc alpha 2-3Gal and fucose residues attached to N-acetylglucosamine for ELAM-1 and HECA-452 binding, this finding suggests that CLA may comprise an additionally sialylated or otherwise modified form of sLex. The identification of a lymphocyte homing receptor for skin may permit novel approaches to the diagnosis and therapy of cutaneous and inflammatory disorders.

Animals↗
PubMed1991

The neutrophil selectin LECAM-1 presents carbohydrate ligands to the vascular selectins ELAM-1 and GMP-140.

LECAM-1 (leukocyte-endothelial cell adhesion molecule 1), the lymphocyte lectin ("selectin") homing receptor for peripheral lymph nodes (PLNs), participates in the earliest interactions of polymorphonuclear neutrophilic leukocytes (PMNs) with inflamed venules. Here, we present evidence that LECAM-1 mediates this function through a novel mechanism--presentation of oligosaccharide ligands to the inducible vascular selectins endothelial-leukocyte adhesion molecule (ELAM-1) and granule membrane protein 140 (GMP-140). PMN, but not lymphocyte, LECAM-1 is modified with the vascular selectin ligand sialyl Lewis x (sLex) and specifically binds ELAM-1-transfected cells. Although only a small fraction of total cell surface sLex, LECAM-1-associated sLex appears to play a prominent role in PMN interactions with cell-associated ELAM-1 and GMP-140, as anti-LECAM-1 monoclonal antibodies or selective removal of cell surface LECAM-1 inhibits PMN binding to vascular selectin transfectants by up to 70%. The enhanced function of LECAM-1-associated sLex may reflect the striking concentration, shown here, of LECAM-1 on PMN surface microvilli, the site of initial cellular contact.

Antibodies, Monoclonal↗
PubMed1991

Two-step model of leukocyte-endothelial cell interaction in inflammation: distinct roles for LECAM-1 and the leukocyte beta 2 integrins in vivo.

The lectin homing receptor LECAM-1 (LAM-1, Leu8) and the beta 2 integrins, particularly Mac-1 (CD11b/CD18), participate in leukocyte-endothelial cell interactions in inflammation. LECAM-1 is rapidly shed while Mac-1 expression is dramatically increased upon neutrophil activation, suggesting functionally distinct roles for these molecules. Using intravital video microscopy, we have compared the effect of antibodies against LECAM-1 and CD18 on leukocyte interactions with rabbit mesenteric venules. Anti-LECAM-1 monoclonal antibody and its Fab fragments inhibited initial reversible leukocyte rolling along the vascular wall. Anti-CD18 monoclonal antibody had no effect on rolling but prevented subsequent firm attachment of leukocytes to venular endothelium. These results support a two-step model of leukocyte-endothelial cell interactions: reversible rolling mediated in part by LECAM-1 facilitates leukocyte recruitment by the local microenvironment and precedes activation-dependent firm attachment involving beta 2 integrins.

Animals↗
PubMed1991

A carbohydrate domain common to both sialyl Le(a) and sialyl Le(X) is recognized by the endothelial cell leukocyte adhesion molecule ELAM-1.

The specificity of endothelial cell leukocyte adhesion molecule-1, ELAM-1, for binding to a panel of carbohydrate structures was determined by a sensitive cell binding assay with immobilized synthetic glycoconjugates. ELAM-1 cDNA transfectants were found to bind Sialyl Lea (sialylated lacto-N-fucopentaose II) or sialylated Lewis a antigen (NeuAc alpha 2-3Gal beta 1-3(Fuc alpha 1-4)GlcNAc), as well as or slightly better than Sialyl Lex (sialylated lacto-N-fucopentaose III) or sialylated Lewis X antigen (NeuAc alpha 2-3 Gal beta 1-4(Fuc alpha 1-3)GlcNAc). A monoclonal antibody, HECA-452, which has been identified recently as recognizing ELAM-1 ligands in addition to those containing Sialyl Lex, was also found to bind both Sialyl Lex and Sialyl Lea. Hard sphere exo-anomeric (HSEA) calculations were performed on these two hexasaccharides. The conformations indicate that Sialyl Lea and Sialyl Lex show a high degree of similarity in both the nonreducing and reducing termini. As Lea and Lex show much weaker reactivity, the determinants recognized by ELAM-1 and HECA-452 probably involve neuraminic acid and fucose residues which on one face of both Sialyl Lex and Sialyl Lea can be similarly positioned. The finding that Sialyl Lea is a potent ligand for ELAM-1 is important, as circulating Sialyl Lea and Sialyl Lex containing mucins which are elevated in the serum of many cancer patients may block leukocyte interactions with ELAM-1 and may contribute to the pathological immunodepression observed in these patients.

Animals↗
PubMed1991

Antibodies against human neutrophil LECAM-1 (LAM-1/Leu-8/DREG-56 antigen) and endothelial cell ELAM-1 inhibit a common CD18-independent adhesion pathway in vitro.

Neutrophil adhesion to interleukin-1 (IL-1)-stimulated human umbilical vein endothelial cells (HUVEC) involves the CD18 family of leukocyte integrins (lymphocyte function-associated antigen-1 [LFA-1], Mac-1, and p150,95) and LECAM-1 (DREG-56/LEU-8/LAM-1 antigen) on neutrophils and intercellular adhesion molecule-1 (ICAM-1) and endothelial leukocyte adhesion molecule-1 (ELAM-1) on the endothelium. In this study, we compare CD18-independent adhesion pathways mediated by neutrophil LECAM-1 and endothelial ELAM-1 and find that these two pathways overlap in a variety of assays: (1) anti-LECAM-1 and anti-ELAM-1 monoclonal antibody (MoAb) inhibit neutrophil binding to HUVEC, and the inhibitory effect is not additive; (2) anti-LECAM-1 MoAb, like anti-ELAM-1 MoAb, inhibits neutrophil binding to HUVEC stimulated for 3 hours with IL-1, but not to HUVEC stimulated for 8 hours, by which time ELAM-1 expression is downregulated; (3) anti-ELAM-1 MoAb has no effect on transendothelial migration, a CD18-dependent, LECAM-1-independent neutrophil function. Interestingly, anti-ELAM MoAb has a reduced but significant inhibitory effect on the adhesion of activated neutrophils that have shed their cell-surface LECAM-1. We also show that neutrophil binding to ELAM-1-transfected L cells is inhibited not only by anti-ELAM-1 but also by anti-LECAM-1 MoAb. These results suggest that LECAM-1 and ELAM-1 can operate in the same adhesion pathway, possibly as a receptor-counterreceptor pair. LECAM-1 and ELAM-1 are likely to interact with other ligands as well, perhaps through carbohydrate determinants that modify more than one glycoprotein.

Animals↗
PubMed1991

ELAM-1 is an adhesion molecule for skin-homing T cells.

Endothelial cell leukocyte adhesion molecule-1 (ELAM-1) has been described as an inducible endothelial cell-adhesion molecule for neutrophils, and is believed to have a key role in the extravasation of these cells at sites of acute inflammation. Here we report that ELAM-1-transfected COS cells also bind a unique skin-associated subset of circulating memory T cells defined by the expression of the cutaneous lymphocyte-associated antigen. T cells expressing this antigen bind at least as well as neutrophils to expressed ELAM-1, whereas other lymphocytes in the peripheral blood bind poorly, or not at all. Immunohistological survey of chronically inflamed tissue specimens revealed that vascular expression of ELAM-1 occurs at cutaneous sites in preference to noncutaneous sites. We conclude that at sites of chronic inflammation, ELAM-1 may function as a skin vascular addressin, a tissue-selective endothelial cell-adhesion molecule for skin-homing memory T lymphocytes.

Animals↗
PubMed1991

The peripheral lymph node homing receptor, LECAM-1, is involved in CD18-independent adhesion of human neutrophils to endothelium.

The binding of polymorphonuclear granulocytes (PMN) to activated vascular endothelium is a crucial step in the recruitment of PMN to an inflammatory site. Studies employing cytokine-activated endothelium in culture have shown that PMN binding involves the CD18 family of leukocyte integrins, but also CD18-independent adhesion mechanism(s) on PMN that have not been defined. We unify here two previously disparate approaches to study cell adhesion events between endothelial cells and leukocytes. We show that antibodies to human LECAM-1, the peripheral lymph node homing receptor that is also expressed on PMN, partially inhibit the adhesion of human PMN not only to HEV in frozen sections of lymph node tissue, but also to cytokine-activated human umbilical vein endothelium in vitro. Inhibition with anti-LECAM-1 antibodies and anti-CD18 antibodies is additive. Furthermore, the anti-LECAM-1 antibodies inhibit the adhesion of CD18-deficient PMN to cytokine activated human endothelial cells. These findings indicate that LECAM-1 and CD18-mediated binding mechanisms are independent, and act coordinately or sequentially to mediate PMN attachment to cytokine activated endothelium.

CD18 Antigens↗
PubMed1991

Late treatment with anti-LFA-1 (CD11a) antibody prevents cerebral malaria in a mouse model.

CBA/Ca mice injected with Plasmodium berghei develop cerebral malaria (CM) characterized by ataxia and progressive paralysis leading to death 7-9 days after experimental infection. The development of cerebral symptoms is a function of the immune response in susceptible strains, and depends on cell-cell interactions involving T helper cells and mononuclear phagocytes. Here we ask whether antibodies to cell adhesion receptors of the immune system can influence the development of CM in this mouse model. When administrated on day 6 after infection, antibody to the leukocyte integrin leukocyte function-antigen-1 (LFA-1) but not antibodies to MAC-1, LECAM-1 (the MEL-14 antigen), alpha 4 integrin or ICAM-1 dramatically reduced the incidence of CM, leading to survival of most mice until the later onset of anemia. Anti-LFA-1 treatment did not result in a substantial decrease in the monocyte accumulation observed in cerebral vessels of susceptible mice. Its efficacy may be related to the broader roles of LFA-1 in cell-cell interactions important in the later pathogenic stages of the immune response to the parasite. Perturbation of immune cell function through interference with cell adhesion mechanisms may offer an important therapeutic tool in acute, life-threatening immune-mediated disorders.

Animals↗
PubMed1991

Dissection of murine lymphocyte-endothelial cell interaction mechanisms by SV-40-transformed mouse endothelial cell lines: novel mechanisms mediating basal binding, and alpha 4-integrin-dependent cytokine-induced adhesion.

Lymph node-derived endothelial cells were immortalized by infection with SV40 virus and subclones expressing the marker MECA 325 specific for high-endothelial venules (HEV) were selected. These transformed mouse endothelial (TME-) cell lines grow permanently without requirement for special growth factors. Staining of the selected clones with endothelium-specific antibodies and with anti-von Willebrand factor antiserum and uptake of acetylated low-density lipoprotein provide evidence for their endothelial origin. The vascular addressins identified by mAbs MECA 79 and MECA 367 on HEV are not detectable, indicating that the phenotype of the cells differs from that of HEV-type endothelium. The TME cells display a constitutive capacity to bind lymphocytes. An additional binding component is induced by treatment of the TME cells with TNF alpha. Antibodies against the homing receptor LECAM-1 (lectin-related leucocyte-endothelial cell adhesion molecule 1), alpha 4-integrins, vascular addressins, LFA-1, or ICAM-1 known to block lymphocyte interaction with particular types of HEV were unable to inhibit the basal adhesion to TME cells, indicating that a further binding mechanism in mice is displayed by this cell type. The adhesion component induced by TNF alpha is mediated by alpha 4-integrins since enhanced binding could be blocked by an antibody against mouse alpha 4 (lymphocyte-Peyer's patch adhesion molecule 1/2). TME cell lines therefore seem to be a useful model for the dissection and analysis of hitherto poorly characterized murine lymphocyte/endothelial cell interaction mechanisms.

Animals↗