scholarly journals Mapping of domains in human laminin using monoclonal antibodies: localization of the neurite-promoting site.

1986 ◽  
Vol 103 (6) ◽  
pp. 2457-2465 ◽  
Author(s):  
E Engvall ◽  
G E Davis ◽  
K Dickerson ◽  
E Ruoslahti ◽  
S Varon ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Basement Membranes ◽  
Globular Domain ◽  
Heparin Binding ◽  
Human Amnion ◽  
Choriocarcinoma Cells ◽  
Single Polypeptide ◽  
Active Fragments ◽  
Blocking Antibodies ◽  
4E10 Antibody

Monoclonal antibodies were made against a truncated form of human laminin isolated from placenta. 12 antibodies were isolated and characterized. All antibodies stained basement membranes in placenta and immunoprecipitated laminin from media of cultured choriocarcinoma cells. Three antibodies, 3E5, 4C7, and 4E10, partially blocked the neurite-promoting activity of laminin. Addition of a second antibody, goat anti-mouse IgG, caused more complete blocking of the activity. Two of the blocking antibodies, 4C7 and 4E10, reacted with epitopes within the globular domain at the end of the long arm of laminin, and the third one, 3E5, reacted at the end of the rod-like portion of the long arm adjacent to the globular domain, as shown by electron microscopy after rotary shadowing. Five nonblocking antibodies used in the same test reacted with epitopes in other domains of the molecule. Blocking antibodies 3E5 and 4E10 could be used in immunoblotting and both antibodies reacted with the same polypeptides in pepsin fragments of human laminin, the predominant polypeptides being approximately 400 kD. When a crude extract of human amnion was used as a source of intact laminin, the 4E10 antibody detected a single polypeptide of approximately 400 kD. A nonblocking antibody, 2E8, which reacted at the center of the laminin cross, reacted predominantly with a 200-kD polypeptide in human laminin fragments and exclusively with a 200-kD polypeptide in amnion extract and in rat laminin. Our results with human laminin match the results by Edgar, D., R. Timpl, and H. Thoenen, 1984, EMBO (Eur. Mol. Biol. Organ.) J., 3:1463-1468, in which the neurite-promoting activity of mouse laminin resides at the end of the long arm, which is also the site for heparin binding. However, since the active fragments of human laminin did not bind to heparin, the neurite-promoting site should be different from the heparin-binding site. Our results further suggest that the neurite-promoting site may be contained in or close to the 400-kD component of laminin.

scholarly journals Selective immunoreactivities of kidney basement membranes to monoclonal antibodies against laminin: localization of the end of the long arm and the short arms to discrete microdomains.

1989 ◽  
Vol 109 (6) ◽  
pp. 3477-3491 ◽  
Author(s):  
D R Abrahamson ◽  
M H Irwin ◽  
P L St John ◽  
E W Perry ◽  
M A Accavitti ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Molecular Orientation ◽  
Three Dimensional ◽  
Basement Membranes ◽  
Globular Domain ◽  
Binding Pattern ◽  
Full Width ◽  
A Site ◽  
Bowman's Capsule ◽  
Rotary Shadowing

To examine the ultrastructural distribution of laminin within kidney basement membranes, we prepared rat anti-mouse laminin mAbs to use in immunolocalization experiments. Epitope domains for these mAbs were established by immunoprecipitation, immunoblotting, affinity chromatography, and rotary shadow EM. One mAb bound to the laminin A and B chains on blots and was located to a site approximately 15 nm from the long arm-terminal globular domain as shown by rotary shadowing. Conjugates of this long arm-specific mAb were coupled to horseradish peroxidase (HRP) and intravenously injected into mice. Kidney cortices were fixed for microscopy 3 h after injection. HRP reaction product was localized irregularly within the renal glomerular basement membrane (GBM) and throughout mesangial matrices. In addition, this mAb bound in linear patterns specifically to the laminae rarae of basement membranes of Bowman's capsule and proximal tubule. This indicates the presence of the long arm immediately beneath epithelial cells in these sites. The laminae densae of these basement membranes were negative by this protocol. In contrast, the lamina rara and densa of distal tubular basement membranes (TBM) were both heavily labeled with this mAb. A different ultrastructural binding pattern was seen with eight other mAbs, including two that mapped to different sites on the short arms by rotary shadowing and five that blotted to a large pepsin-resistant laminin fragment (P1). These latter mAbs bound weakly or not at all to GBM but all bound throughout mesangial matrices. In contrast, discrete spots of HRP reaction product were seen across all layers of Bowman's capsule BM and proximal TBM. These same mAbs, however, bound densely across the full width of distal TBM. Our findings therefore show that separate strata of different basement membranes are variably immunoreactive to these laminin mAbs. The molecular orientation or integration of laminin into the three dimensional BM meshwork therefore varies with location. Alternatively, there may be a family of distinct laminin-like molecules distributed within basement membranes.

scholarly journals Mapping of epitopes for monoclonal antibodies against human platelet thrombospondin with electron microscopy and high sensitivity amino acid sequencing.

1985 ◽  
Vol 101 (4) ◽  
pp. 1434-1441 ◽  
Author(s):  
N J Galvin ◽  
V M Dixit ◽  
K M O'Rourke ◽  
S A Santoro ◽  
G A Grant ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Monoclonal Antibodies ◽  
Human Platelet ◽  
High Sensitivity ◽  
Binding Domain ◽  
Peptide Chain ◽  
Dimensional Structure ◽  
Globular Domain ◽  
Heparin Binding ◽  
Heparin Binding Domain

A panel of monoclonal antibodies (Mab's) has been raised against human platelet thrombospondin (TSP). One Mab, designated A2.5, inhibits the hemagglutinating activity of TSP and immunoprecipitates the NH2 terminal 25 kD heparin binding domain of TSP (Dixit, V.M., D. M. Haverstick, K. M. O'Rourke, S. W. Hennessy, G. A. Grant, S. A. Santoro, and W. A. Frazier, 1985, Biochemistry, in press). Another Mab, C6.7, blocks the thrombin-stimulated aggregation of live platelets and immunoprecipitates an 18-kD fragment distinct from the heparin binding domain (Dixit, V. M., D. M. Haverstick, K. M. O'Rourke, S. W. Hennessy, G. A. Grant, S. A. Santoro, and W. A. Frazier, 1985, Proc. Natl. Acad. Sci. 82: 3472-3476). To determine the relative locations of the epitopes for these Mabs in the three-dimensional structure of TSP, we have examined TSP-Mab complexes by electron microscopy of rotary-shadowed proteins. The TSP molecule is composed of three 180-kD subunits, each of which consists of a small globular domain (approximately 8 nm diam) and a larger globular domain (approximately 16 nm diam) connected by a thin, flexible strand. The subunit interaction site is on the thin connecting strands, nearer the small globular domains. Mab A2.5 binds to the cluster of three small domains, indicating that this region contains the heparin binding domain and thus represents the NH2 termini of the TSP peptide chains. Mab C6.7 binds to the large globular domains on the side opposite the point at which the connecting strand enters the domain, essentially the maximum possible distance from the A2.5 epitope. Using high sensitivity automated NH2 terminal sequencing of TSP chymotryptic peptides we have ordered these fragments within the TSP peptide chain and have confirmed that the epitope for C6.7 in fact lies near the extreme COOH terminus of the peptide chain. In combination with other data, we have been able to construct a map of the linear order of the identified domains of TSP that indicates that to a large extent, the domains are arranged co-linearly with the peptide chain.

NEUROBLASTOMA IMMUNOTHERAPY

2019 ◽  
Vol 65 (2) ◽  
pp. 181-187
Author(s):  
Aleksandr Druy ◽  
Svetlana Kuleva
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
High Risk ◽  
Checkpoint Inhibitors ◽  
Innate And Adaptive Immunity ◽  
Car T Cells ◽  
Car T ◽  
Membrane Antigens ◽  
Theoretical Evidence ◽  
Blocking Antibodies

The recent data about innate and adaptive immunity against neuroblastoma are described in the article. The era of neuroblastoma immunotherapy started since the evidence of anti-GD2 monoclonal antibodies efficiency. Nowadays monoclonal antibodies against GD2 are introduced into schemes of maintenance therapy for high-risk neuroblastoma patients. Developing of T-cells expressing chimeric antigen receptor (CAR-T cells) directed to membrane antigens is the perspective of neuroblastoma immunotherapy. PD1/PD-L1 blocking antibodies as immune checkpoint inhibitors have the theoretical evidence of potential effectiveness. Application of immunotherapeutic approaches in high-risk neuroblastoma patients together with conventional multimodal therapies requires further investigation.

Immunity in human schistosomiasis mansoni: prevention by blocking antibodies of the expression of immunity in young children

Parasitology ◽  
1987 ◽  
Vol 94 (2) ◽  
pp. 281-300 ◽  
Author(s):  
A. E. Butterworth ◽  
R. Bensted-Smith ◽  
A. Capron ◽  
M. Capron ◽  
P. R. Dalton ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Young Children ◽  
Immune Responses ◽  
Blood Eosinophil ◽  
Strongly Correlated ◽  
Igg Antibodies ◽  
Blood Samples ◽  
Slow Development ◽  
The Face ◽  
Blocking Antibodies

SUMMARYA total of 129 children were treated forSchistosoma mansoniinfections, and followed for intensity of reinfection at3-monthly intervals over a 21-month period. Blood samples were taken before treatment and at 5 weeks and 6, 12 and 18 months after treatment. This paper presents a statistical analysis of the relationship between various immune responses and subsequent reinfection. Responses analysed were: blood eosinophil levels; IgE antibodies against schistosomulum antigens; IgG antibodies mediating eosinophil-dependent killing of schistosomula; antibodies inhibiting the binding to schistosomulum antigens of two rat monoclonal antibodies that also recognize egg antigens; the levels of anti-adult worm and of anti-egg (total, IgM and IgG) antibodies; and IgM anti-schistosomulum antibodies. Results for each assay were well correlated for each of the five separate blood samples. None of the assays were predictive of resistance to reinfection, butsusceptibilityto reinfection was strongly correlated with results in the preceding blood samples for total anti-egg antibodies and the inhibition of binding of one of the two monoclonal antibodies. Further analysis also revealed a correlation between reinfection intensities and both IgM anti-schistosomulum antibodies and IgM and IgG anti-egg antibodies. These results are consistent with the hypothesis that early infections elicit the development, in response to egg antigens, of antibodies that block immune mechanisms directed against schistosomula. Blocking antibodies may be IgM, but might also be of an ineffective IgG isotype. The existence of such antibodies in young children would explain the slow development of immunity in the face of a range of detectable, potentially protective immune responses.

Regulation of human lung fibroblast phenotype and function by vitronectin and vitronectin integrins

2001 ◽  
Vol 114 (19) ◽  
pp. 3507-3516 ◽  
Author(s):  
Amelia K. Scaffidi ◽  
Yuben P. Moodley ◽  
Markus Weichselbaum ◽  
Philip J. Thompson ◽  
Darryl A. Knight
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Monoclonal Antibodies ◽  
Human Lung ◽  
Stress Fibers ◽  
Collagen Gels ◽  
Human Lung Fibroblast ◽  
Myofibroblast Phenotype ◽  
And Function ◽  
Blocking Antibodies

Myofibroblasts, characterised by high expression of α-smooth muscle actin (α-SMA), are important and transient cells in normal wound healing but are found in increased number in various pathological conditions of the lung including asthma and pulmonary fibrosis. The mechanisms that regulate the myofibroblast phenotype are unknown but are likely to involve signals from the extracellular matrix transmitted via specific integrins. Vitronectin is a glycoprotein released during inflammation and has been shown to regulate the phenotype of vascular smooth muscle cells via αv and β1 integrins. In the current study we have examined whether vitronectin influences the phenotype and function of normal human lung fibroblasts (HFL-1). Incubation of HFL-1 cells with vitronectin induced a concentration-dependent reduction in α-SMA expression. By contrast, function-blocking monoclonal antibodies to the vitronectin integrins αv, β1, αvβ3 and αvβ5 induced the expression of α-SMA and its organization into stress fibers. Expression of α-SMA induced by all function-blocking monoclonal antibodies was abrogated by inhibition of protein kinase C and phosphatidylinositol-3 kinase, but the effects of inhibition of other signalling pathways was integrin dependent. Exposure to other extracellular matrix proteins such as fibronectin, collagen or their integrins did not influence expression of α-SMA. The expression and organization of α-SMA induced by exposure to function-blocking antibodies was translated into an augmented capacity of HFL-1 cells to contract fibroblast populated collagen gels. By contrast, contraction of collagen gels following incubation with vitronectin was not significantly different to control. This study has shown that vitronectin influences the phenotype and behaviour of HFL-1 cells by downregulating the expression of α-SMA and reducing their contractile ability. By contrast, occupancy of specific integrins by function-blocking antibodies upregulated the expression of α-SMA and induced the formation of functional stress fibers capable of contracting collagen gels. These results suggest that vitronectin modulates the fibroblast-myofibroblast phenotype, implying an important role in the remodelling process during lung development or response to injury.

scholarly journals Monoclonal antibodies to laminin reveal the heterogeneity of basement membranes in the developing and adult mouse tissues.

1984 ◽  
Vol 98 (3) ◽  
pp. 971-979 ◽  
Author(s):  
Y J Wan ◽  
T C Wu ◽  
A E Chung ◽  
I Damjanov
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Adult Mouse ◽  
Basement Membranes ◽  
Newborn Mouse ◽  
Preimplantation Stage ◽  
Mouse Tissues ◽  
Reichert's Membrane ◽  
Anatomic Locations ◽  
Immunohistochemical Studies

Two monoclonal antibodies raised against laminin isolated from a mouse parietal yolk sac cell line were used for immunohistochemical studies of basement membranes of the mouse embryo and various fetal and adult tissues. No immunoreactivity with either of the two monoclonal antibodies could be detected in the preimplantation-stage embryos, although it has been shown that these embryos contain extracellular laminin reactive with the conventional polyclonal antilaminin antibodies. Reichert's membrane in early postimplantation stages of development reacted with the monoclonal antibody LAM-I but not with the antibody LAM-II. However, from day 8 of pregnancy onward the Reichert's membrane reacted with both antibodies. Basement membranes of the embryo proper were unreactive with both monoclonal antibodies until day 12 of pregnancy. By day 14 some basement membranes of the fetal tissues became reactive with one or both monoclonal antibodies, whereas others remained still unreactive. In the 17-d fetus and the newborn mouse most of the basement membranes reacted with both monoclonal antibodies, whereas others still reacted with only one. Similar heterogeneity in the immunoreactivity of basement membranes of various tissues was noted in the adult mouse as well. These results indicate that the immunoreactivity of laminin in the extracellular matrix changes during development and that the basement membranes in various anatomic locations display heterogeneity even in the adult mouse.

scholarly journals A Novel Panel of Rabbit Monoclonal Antibodies and Their Diverse Applications Including Inhibition of Clostridium perfringens Epsilon Toxin Oligomerization

Antibodies ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 37 ◽  
Author(s):  
Jennifer Linden ◽  
Kiel Telesford ◽  
Samantha Shetty ◽  
Paige Winokour ◽  
Sylvia Haigh ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Monoclonal Antibodies ◽  
Western Blot ◽  
Clostridium Perfringens ◽  
Specificity And Sensitivity ◽  
Epsilon Toxin ◽  
Blocking Antibodies

The pore-forming epsilon toxin (ETX) produced by Clostridium perfringens is among the most lethal bacterial toxins known. Sensitive antibody-based reagents are needed to detect toxin, distinguish mechanisms of cell death, and prevent ETX toxicity. Using B-cell immuno-panning and cloning techniques, seven ETX-specific monoclonal antibodies were generated from immunized rabbits. ETX specificity and sensitivity were evaluated via western blot, ELISA, immunocytochemistry (ICC), and flow cytometry. ETX-neutralizing function was evaluated both in vitro and in vivo. All antibodies recognized both purified ETX and epsilon protoxin via western blot with two capable of detecting the ETX-oligomer complex. Four antibodies detected ETX via ELISA and three detected ETX bound to cells via ICC or flow cytometry. Several antibodies prevented ETX-induced cell death by either preventing ETX binding or by blocking ETX oligomerization. Antibodies that blocked ETX oligomerization inhibited ETX endocytosis and cellular vacuolation. Importantly, one of the oligomerization-blocking antibodies was able to protect against ETX-induced death post-ETX exposure in vitro and in vivo. Here we describe the production of a panel of rabbit monoclonal anti-ETX antibodies and their use in various biological assays. Antibodies possessing differential specificity to ETX in particular conformations will aid in the mechanistic studies of ETX cytotoxicity, while those with ETX-neutralizing function may be useful in preventing ETX-mediated mortality.

scholarly journals The Babesia bovis Merozoite Surface Antigen 1 Hypervariable Region Induces Surface-Reactive Antibodies That Block Merozoite Invasion

2006 ◽  
Vol 74 (6) ◽  
pp. 3663-3667 ◽  
Author(s):  
Tanya LeRoith ◽  
Shawn J. Berens ◽  
Kelly A. Brayton ◽  
Stephen A. Hines ◽  
Wendy C. Brown ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Surface Antigen ◽  
Hypervariable Region ◽  
Babesia Bovis ◽  
Related Family ◽  
Erythrocyte Invasion ◽  
Merozoite Surface Antigen ◽  
Carboxy Terminal ◽  
Blocking Antibodies

ABSTRACT A hypervariable region (HVR) previously identified in the carboxy-terminal one-third of the Babesia bovis variable merozoite surface antigen family was more extensively analyzed in merozoite surface antigen 1 (MSA-1) from 16 strains and isolates. The MSA-1 HVR is proline rich and contains three semiconserved motifs nearly identical to those described for the related family member MSA-2. Two MSA-1-specific monoclonal antibodies previously shown to be reactive with the merozoite surface bound to a recombinant construct encoding the HVR, indicating that the HVR is surface exposed and accessible to antibody binding. Importantly, these surface-reactive, HVR-specific monoclonal antibodies were capable of inhibiting merozoite infectivity of the host erythrocyte in vivo. The results indicate that the MSA-1 HVR is involved in erythrocyte invasion and suggest that selection of MSA-1 variants may be driven by invasion-blocking antibodies.

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