scholarly journals Monoclonal antibodies as probes of the distribution of ZP-2, the major sulfated glycoprotein of the murine zona pellucida.

1984 ◽  
Vol 98 (3) ◽  
pp. 795-800 ◽  
Author(s):  
I J East ◽  
J Dean
Keyword(s):  
Extracellular Matrix ◽  
Monoclonal Antibodies ◽  
Zona Pellucida ◽  
Binding Sites ◽  
Antigenic Site ◽  
Matrix Proteins ◽  
Mouse Tissue ◽  
Cell Embryo ◽  
Embryo Stage ◽  
Mouse Egg

Three sulfated glycoproteins (ZP-1, ZP-2, and ZP-3) make up the zona pellucida, an extracellular glycocalyx that surrounds mouse oocytes. We have produced five monoclonal antibodies specific to the zona. All five immunoprecipitated ZP-2, and in addition, two of the antibodies immunoprecipitated ZP-3. This suggests the presence of either a common antigenic site or one made up in part by each of the two glycoproteins. The monoclonal antibodies bound to approximately 1.3 X 10(8) binding sites per ovulated mouse egg which represents 2% of the total number of ZP-2 molecules present in the zona. ZP-2 appeared to be present throughout the zona and indirect immunofluorescence revealed a fibrous pattern with no evidence of localization. Furthermore, this pattern of distribution, which was identical for all five monoclones, remained constant after fertilization at the two-cell embryo stage. Laser photobleaching demonstrated that ZP-2 is stably integrated in the extracellular matrix of the zona pellucida. No mouse tissue other than the ovary contained ZP-2 and ZP-2 is antigenically distinct from other previously described extracellular matrix proteins.

scholarly journals Inhibition of acanthamoeba actomyosin-II ATPase activity and mechanochemical function by specific monoclonal antibodies.

1984 ◽  
Vol 99 (3) ◽  
pp. 1024-1033 ◽  
Author(s):  
D P Kiehart ◽  
T D Pollard
Keyword(s):  
Monoclonal Antibodies ◽  
Atpase Activity ◽  
Conformational Changes ◽  
Binding Sites ◽  
Polyclonal Antibodies ◽  
Myosin Ii ◽  
Antigenic Site ◽  
Actin Binding ◽  
Filamentous Form ◽  
Antibody Effects

Monoclonal and polyclonal antibodies that bind to myosin-II were tested for their ability to inhibit myosin ATPase activity, actomyosin ATPase activity, and contraction of cytoplasmic extracts. Numerous antibodies specifically inhibit the actin activated Mg++-ATPase activity of myosin-II in a dose-dependent fashion, but none blocked the ATPase activity of myosin alone. Control antibodies that do not bind to myosin-II and several specific antibodies that do bind have no effect on the actomyosin-II ATPase activity. In most cases, the saturation of a single antigenic site on the myosin-II heavy chain is sufficient for maximal inhibition of function. Numerous monoclonal antibodies also block the contraction of gelled extracts of Acanthamoeba cytoplasm. No polyclonal antibodies tested inhibited ATPase activity or gel contraction. As expected, most antibodies that block actin-activated ATPase activity also block gel contraction. Exceptions were three antibodies M2.2, -15, and -17, that appear to uncouple the ATPase activity from gel contraction: they block gel contraction without influencing ATPase activity. The mechanisms of inhibition of myosin function depends on the location of the antibody-binding sites. Those inhibitory antibodies that bind to the myosin-II heads presumably block actin binding or essential conformational changes in the myosin heads. A subset of the antibodies that bind to the proximal end of the myosin-II tail inhibit actomyosin-II ATPase activity and gel contraction. Although this part of the molecule is presumably some distance from the ATP and actin-binding sites, these antibody effects suggest that structural domains in this region are directly involved with or coupled to catalysis and energy transduction. A subset of the antibodies that bind to the tip of the myosin-II tail appear to inhibit ATPase activity and contraction through their inhibition of filament formation. They provide strong evidence for a substantial enhancement of the ATPase activity of myosin molecules in filamentous form and suggest that the myosin filaments may be required for cell motility.

scholarly journals Neutralization of Human Papillomavirus with Monoclonal Antibodies Reveals Different Mechanisms of Inhibition

2007 ◽  
Vol 81 (16) ◽  
pp. 8784-8792 ◽  
Author(s):  
Patricia M. Day ◽  
Cynthia D. Thompson ◽  
Christopher B. Buck ◽  
Yuk-Ying S. Pang ◽  
Douglas R. Lowy ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Monoclonal Antibodies ◽  
Human Papillomavirus ◽  
Cell Surface ◽  
Binding Sites ◽  
Neutralizing Antibodies ◽  
Hpv Infection ◽  
Heparan Sulfate Proteoglycans ◽  
Hacat Cells ◽  
Block Association

ABSTRACT The mechanisms of human papillomavirus (HPV) neutralization by antibodies are incompletely understood. We have used HPV16 pseudovirus infection of HaCaT cells to analyze how several neutralizing monoclonal antibodies (MAbs) generated against HPV16 L1 interfere with the process of keratinocyte infection. HPV16 capsids normally bind to both the cell surface and extracellular matrix (ECM) of HaCaT cells. Surprisingly, two strongly neutralizing MAbs, V5 and E70, did not prevent attachment of capsids to the cell surface. However, they did block association with the ECM and prevented internalization of cell surface-bound capsids. In contrast, MAb U4 prevented binding to the cell surface but not to the ECM. The epitope recognized by U4 was inaccessible when virions were bound to the cell surface but became accessible after endocytosis, presumably coinciding with receptor detachment. Treatment of capsids with heparin, which is known to interfere with binding to cell surface heparan sulfate proteoglycans (HSPGs), also resulted in HPV16 localization to the ECM. These results suggest that the U4 epitope on the intercapsomeric C-terminal arm is likely to encompass the critical HSPG interaction residues for HPV16, while the V5 and E70 epitopes at the apex of the capsomer overlap the ECM-binding sites. We conclude that neutralizing antibodies can inhibit HPV infection by multiple distinct mechanisms, and understanding these mechanisms can add insight to the HPV entry processes.

Mediation of endothelial injury following neutrophil adherence to extracellular matrix

1993 ◽  
Vol 264 (4) ◽  
pp. L401-L405 ◽  
Author(s):  
R. A. Kaslovsky ◽  
L. Lai ◽  
K. Parker ◽  
A. B. Malik
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Monoclonal Antibodies ◽  
Endothelial Permeability ◽  
Endothelial Injury ◽  
Matrix Proteins ◽  
Extracellular Matrix Components ◽  
The Matrix ◽  
Neutrophil Adherence ◽  
Permeability Increase

Since polymorphonuclear leukocytes (PMN) rapidly migrate across the endothelial barrier and attach to extracellular matrix components, we tested the hypothesis that adhesion of PMN to matrix proteins can mediate endothelial injury following PMN activation. Studies were made using gelatin- and fibronectin-coated polycarbonate microporous filters (10 microns thick) on which confluent monolayers of bovine pulmonary microvessel endothelial cells were grown. PMN were layered either directly onto endothelial cells (at a ratio of 10:1) (“upright system”) or onto gelatin- and fibronectin-coated filters with the endothelial monolayer grown on the underside of the filter without contact between PMN and endothelial cells (“inverted system”). PMN were activated with phorbol 12-myristate 13-acetate (PMA; 5 x 10(-9) M) in both systems. PMN activation increased endothelial permeability to 125I-labeled albumin in upright as well as inverted systems. Pretreatment of PMN with anti-CD18 monoclonal antibodies IB4 or R15.7, which inhibited PMN adherence to matrix constituents as well as to endothelial cells, prevented the permeability increase in both configurations. This effect of anti-CD18 monoclonal antibodies (mAbs) was not ascribed to a reduction in PMN activation, since PMA-induced superoxide generation was unaffected. We conclude that activation of PMN adherent to extracellular matrix proteins increases endothelial permeability to albumin and that this response is dependent on PMN adhesion to the matrix. The results support the concept that PMN-mediated increase in endothelial permeability is the result of “targeted” release of PMN products independent of whether the PMN are adherent to the extracellular matrix or the endothelium.

Improved Adhesion and Proliferation of Human Endothelial Cells on Polyethylene Precoated with Monoclonal Antibodies Directed against Cell Membrane Antigens and Extracellular Matrix Proteins

1991 ◽  
Vol 66 (06) ◽  
pp. 715-724 ◽  
Author(s):  
Albert Dekker ◽  
André A Poot ◽  
Jan A van Mourik ◽  
Martin P A Workel ◽  
Tom Beugeling ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Monoclonal Antibodies ◽  
Endothelial Cell ◽  
Platelet Reactivity ◽  
Extracellular Matrix Proteins ◽  
Matrix Proteins ◽  
Specific Monoclonal Antibody ◽  
Human Endothelial Cells ◽  
Membrane Antigens

SummaryEndothelial cell seeding may improve the patency of synthetic vascular grafts provided that platelet reactivity of non-endothelialized sites is not increased. We have investigated if surface-adsorbed monoclonal antibodies directed against endothelial cell membrane proteins and against extracellular matrix proteins promote the adhesion and proliferation of cultured human endothelial cells, without causing platelet deposition at non-endothelialized sites. Adhesion of endothelial cells onto polyethylene coated with monoclonal antibodies directed against endothelial cell-specific membrane antigens, integrin receptors and glycoprotein CD31 was equal to or higher than adhesion onto fibronectin-coated polyethylene. Endothelial cells did not proliferate on these surface-adsorbed antibodies. However, pre-coating of polyethylene with mixtures of endothelial cell-specific monoclonal antibodies and monoclonal antibodies directed against fibronectin or von Willebrand factor, resulted in relatively high adhesion and optimal proliferation. Platelet reactivity of the polyethylene surface was found to significantly increase after adsorption of fibronectin, endothelial cell-specific monoclonal antibody or its Fc fragments. In contrast, adsorption of F(ab')2 fragments of endothelial cell-specific monoclonal antibody did not promote platelet deposition. Therefore, it is concluded that coating of vascular graft materials with mixtures of F(ab')2 fragments of monoclonal antibodies specifically directed against endothelial cells and against extracellular matrix proteins may be an effective way to both promote the growth of seeded endothelial cells and limit platelet-graft interaction.

scholarly journals Immunohistological characteristics of collagen, laminin and sialoadhesin in the rat submandibular salivary gland during ontogenesis

2003 ◽  
Vol 50 (4) ◽  
pp. 179-183
Author(s):  
Ivan Dozic ◽  
Miodrag Colic
Keyword(s):  
Extracellular Matrix ◽  
Monoclonal Antibodies ◽  
Salivary Gland ◽  
Postnatal Development ◽  
Basal Membrane ◽  
Myoepithelial Cells ◽  
Matrix Proteins ◽  
Submandibular Salivary Gland ◽  
Ductal Cells ◽  
Positive Reactivity

The aim of this study was to investigate the expression of collagen, laminin and sialoadhesin in the rat submandibular salivary gland during postnatal development (1st, 30th,and 60th day) by using various monoclonal antibodies (mAbs) RMC-23 (specific for collagen),a6?1 (specific for laminin) and ED3 (specific for sialoadhezin). These components of extracellular matrix were detected. RMC-23 mAb showed strong positivity to the basal membranes of the ductal system (intercalated, striated and excretory ducts) and of intersticium. Increased expression in the basal membrane of acini during development of glands was noted. Similar immunoreactivity was shown by?mAb but the intersticium showed a negative reaction to 1a6 this antibody. Positive reactivity of ?1a6 mAb of epithelial ductal cells, particularly of the neonatal animals, was found. In contrast to ? 1a6 and RMC23 mAbs, ED3 mAb was increasingly expressed in the myoepithelial cells during ontogenesis. Our findings regarding the immunoreactivity of collagens and laminins are in accordance with the findings of other autors. The very interesting finding of sialoadhesin in myoepithelial cells of the rat submandibular salivary gland, which is not described in literature and needs further investigation. Our results suggest that adhesion molecules and extracellular matrix proteins have an important biochemical role during postnatal development of the submandibular salivary gland.

Development of an in vitro Model for the Study of the Response of Equine Tendon Fibroblasts to Injury and Medication

1997 ◽  
Vol 10 (01) ◽  
pp. 6-11 ◽  
Author(s):  
R. F. Rosenbusch ◽  
L. C. Booth ◽  
L. A. Dahlgren
Keyword(s):  
Electron Microscopy ◽  
Extracellular Matrix ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Tendon Healing ◽  
Matrix Proteins ◽  
Isolated Cells ◽  
Superficial Digital Flexor Tendon ◽  
Vitro Model

SummaryEquine tendon fibroblasts were isolated from explants of superficial digital flexor tendon, subcultured and maintained in monolayers. The cells were characterized by light microscopy, electron microscopy and radiolabel studies for proteoglycan production. Two predominant cell morphologies were identified. The cells dedifferentiated toward a more spindle shape with repeated subcultures. Equine tendon fibroblasts were successfully cryopreserved and subsequently subcultured. The ability to produce proteoglycan was preserved.The isolated cells were identified as fibroblasts, based on their characteristic shape by light microscopy and ultrastructure and the active production of extracellular matrix proteins. Abundant rough endoplasmic reticulum and the production of extracellular matrix products demonstrated active protein production and export. Proteoglycans were measurable via liquid scintillation counting in both the cell-associated fraction and free in the supernatant. This model is currently being utilized to study the effects of polysulfated glycosaminoglycan on tendon healing. Future uses include studying the effects of other pharmaceuticals, such as hyaluronic acid, on tendon healing.A model was developed for in vitro investigations into tendon healing. Fibroblasts were isolated from equine superficial digital flexor tendons and maintained in monolayer culture. The tenocytes were characterized via light and electron microscopy. Proteoglycan production was measured, using radio-label techniques. The fibroblasts were cryopreserved and subsequently subcultured. The cells maintained their capacity for proteoglycan production, following repeated subculturing and cryopreservation.

Effect of Lipoprotein(a) and LDL on Plasminogen Binding to Extracellular Matrix and on Matrix-dependent Plasminogen Activation by Tissue Plasminogen Activator

1996 ◽  
Vol 75 (03) ◽  
pp. 497-502 ◽  
Author(s):  
Hadewijch L M Pekelharing ◽  
Henne A Kleinveld ◽  
Pieter F C.C.M Duif ◽  
Bonno N Bouma ◽  
Herman J M van Rijn
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Binding Sites ◽  
Umbilical Vein ◽  
Single Step ◽  
Plasminogen Activation ◽  
Structural Homology ◽  
Tissue Plasminogen ◽  
Umbilical Vein Endothelial Cells

SummaryLp(a) is an LDL-like lipoprotein plus an additional apolipoprotein apo(a). Based on the structural homology of apo(a) with plasminogen, it is hypothesized that Lp(a) interferes with fibrinolysis. Extracellular matrix (ECM) produced by human umbilical vein endothelial cells was used to study the effect of Lp(a) and LDL on plasminogen binding and activation. Both lipoproteins were isolated from the same plasma in a single step. Plasminogen bound to ECM via its lysine binding sites. Lp(a) as well as LDL were capable of competing with plasminogen binding. The degree of inhibition was dependent on the lipoprotein donor as well as the ECM donor. When Lp(a) and LDL obtained from one donor were compared, Lp(a) was always a much more potent competitor. The effect of both lipoproteins on plasminogen binding was reflected in their effect on plasminogen activation. It is speculated that Lp(a) interacts with ECM via its LDL-like lipoprotein moiety as well as via its apo(a) moiety.

Extracellular matrix proteins control the growth of cerebellar medulloblastoma cells

2004 ◽  
Vol 216 (03) ◽  
Author(s):  
U Schüller ◽  
W Hartmann ◽  
A Koch ◽  
K Schilling ◽  
OD Wiestler ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Extracellular Matrix Proteins ◽  
Matrix Proteins ◽  
Cerebellar Medulloblastoma
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