Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A monoclonal antibody that recognizes the E domain of staphylococcal protein A.

ABSTRACT: Staphylococcal protein A (SpA) binds Fc? and VH3 clan Fab domains of human and animal immunoglobulin (Ig) with each of its five Ig binding domains (IgBDs), thereby supporting Staphylococcus aureus escape from opsonophagocytic killing and suppressing adaptive B cell responses. The variant SpAKKAA cannot bind Ig yet retains antigenic properties that elicit SpA-neutralizing antibodies and disease protection in mice, whereas S. aureus infection or SpA-immunization cannot elicit neutralizing antibodies. As a test for this model, we analyzed here mAb 358A76, which was isolated from SpA-immunized mice. Unlike SpAKKAA-derived mAbs, mAb 358A76 binds only the first IgBD (E) but not any of the other four IgBDs (D-A-B-C) and its binding can neutralize only the E domain of SpA, which does not provide disease protection in mice. These results are in agreement with a model whereby wild-type SpA-immunization generates a limited antibody response without neutralizing and/or disease protective attributes.

SUBMITTER: Kim HK

PROVIDER: S-EPMC6211298 | biostudies-other | 2014 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

A monoclonal antibody that recognizes the E domain of staphylococcal protein A.

Kim Hwan Keun HK Emolo Carla C Missiakas Dominique D Schneewind Olaf O

Vaccine 20131127 4

Staphylococcal protein A (SpA) binds Fcγ and VH3 clan Fab domains of human and animal immunoglobulin (Ig) with each of its five Ig binding domains (IgBDs), thereby supporting Staphylococcus aureus escape from opsonophagocytic killing and suppressing adaptive B cell responses. The variant SpAKKAA cannot bind Ig yet retains antigenic properties that elicit SpA-neutralizing antibodies and disease protection in mice, whereas S. aureus infection or SpA-immunization cannot elicit neutralizing antibodi ...[more]

PMID: 24291195

Similar Datasets

Identification of a Neutralizing Monoclonal Antibody That Recognizes a Unique Epitope on Domain III of the Envelope Protein of Tembusu Virus.

Project description:Domain III of the envelope protein (EDIII) is the major target of flavivirus neutralizing antibody. To date, little is known regarding antibody-mediated neutralization of Tembusu virus (TMUV), a novel flavivirus emerging in duck in 2010. Here, a novel monoclonal antibody (MAb), designated 12F11, was prepared by immunization of mice with recombinant EDIII (rEDIII) protein. Using virus neutralization test, 12F11 in undiluted ascites neutralized the TMUV infectivity to induce the development of cytopathic effects in BHK-21 cells, indicating that 12F11 exhibits a neutralizing activity. The neutralizing activity of 12F11 was confirmed by plaque reduction neutralization test, in which 12F11 reduced significantly the number of plaques produced by TMUV in BHK-21 cells. Western blot analyses of a series of truncated rEDIII proteins showed that the epitope recognized by 12F11 includes amino acids between residues 8 and 77 of EDIII protein. Function analysis demonstrated that 12F11 neutralizes TMUV infection at virus adsorption and at a step after adsorption to a certain extent. The present study provides an important step towards elucidating antibody-mediated neutralization of TMUV.

| S-EPMC7354527 | biostudies-literature

The mAB 13A4 monoclonal antibody to the mouse PROM1 protein recognizes a structural epitope.

Project description:PROM1 (CD133, AC133) is a protein that is required for the maintenance of primary cilia. Mutation in the Prom1 gene in humans and animal models are associated with several forms of retinal degeneration. mAB 13A4 is the main reagent used to detect the mouse PROM1 protein. We endeavored to map the epitope of the rat monoclonal antibody mAB 13A4 to the mouse PROM1 protein. Deletion mutagenesis demonstrated that mAB 13A4 recognizes a structural epitope that is stabilized by two of the extracellular domains of PROM1. Furthermore, the affinity of mAB 13A4 to the major PROM1 isoform in photoreceptor cells is significantly reduced due to the inclusion of a photoreceptor-specific alternative exon in the third extracellular domain. Interestingly, a deletion in the photoreceptor specific isoform of six amino acids adjacent to the alternative exon restored the affinity of mAB 13A4 to PROM1. The results of the mutagenesis are consistent with the computationally predicted helical bundle structure of PROM1 and point to the utility of mAB 13A4 for evaluating the effect of mutations on the PROM1 structure. Our results show that the PROM1 isoform composition needs to be considered when interpreting tissue and developmental expression data produced by mAB 13A4.

| S-EPMC9550058 | biostudies-literature

A protective human monoclonal antibody targeting the West Nile virus E protein preferentially recognizes mature virions.

Project description:West Nile virus (WNV), a member of the Flavivirus genus, is a leading cause of viral encephalitis in the United States1. The development of neutralizing antibodies against the flavivirus envelope (E) protein is critical for immunity and vaccine protection2. Previously identified candidate therapeutic mouse and human neutralizing monoclonal antibodies (mAbs) target epitopes within the E domain III lateral ridge and the domain I-II hinge region, respectively3. To explore the neutralizing antibody repertoire elicited by WNV infection for potential therapeutic application, we isolated ten mAbs from WNV-infected individuals. mAb WNV-86 neutralized WNV with a 50% inhibitory concentration of 2 ng ml-1, one of the most potently neutralizing flavivirus-specific antibodies ever isolated. WNV-86 targets an epitope in E domain II, and preferentially recognizes mature virions lacking an uncleaved form of the chaperone protein prM, unlike most flavivirus-specific antibodies4. In vitro selection experiments revealed a neutralization escape mechanism involving a glycan addition to E domain II. Finally, a single dose of WNV-86 administered two days post-infection protected mice from lethal WNV challenge. This study identifies a highly potent human neutralizing mAb with therapeutic potential that targets an epitope preferentially displayed on mature virions.

| S-EPMC6435290 | biostudies-literature

A human monoclonal antibody that specifically binds and inhibits the staphylococcal complement inhibitor protein SCIN.

Project description:Staphylococcus aureus is a serious public health burden causing a wide variety of infections. Earlier detection of such infections could result in faster and more directed therapies that also prevent resistance development. Human monoclonal antibodies (humAbs) are promising tools for diagnosis and therapy owing to their relatively straightforward synthesis, long history of safe clinical use and high target specificity. Here we show that the humAb 6D4, which was obtained from a random screen of B-cells producing antibodies that bind to whole cells of S. aureus, targets the staphylococcal complement inhibitor (SCIN). The epitope recognized by 6D4 was localized to residues 26 to 36 in the N-terminus of SCIN, which overlap with the active site. Accordingly, 6D4 can inhibit SCIN activity as demonstrated through the analysis of C3b deposition on S. aureus cells and complement-induced lysis of rabbit erythrocytes. Importantly, while SCIN is generally regarded as a secreted virulence factor, 6D4 allowed detection of strongly increased SCIN binding to S. aureus cells upon exposure to human serum, relating to the known binding of SCIN to C3 convertases deposited on the staphylococcal cell surface. Lastly, we show that labeling of humAb 6D4 with a near-infrared fluorophore allows one-step detection of SCIN-producing S. aureus cells. Together, our findings show that the newly described humAb 6D4 specifically recognizes S. aureus SCIN, which can potentially be used for detection of human serum-incubated S. aureus strains expressing SCIN.

| S-EPMC5955450 | biostudies-literature

A cancer-specific monoclonal antibody recognizes the aberrantly glycosylated podoplanin.

Project description:Podoplanin (PDPN/Aggrus/T1α), a platelet aggregation-inducing mucin-like sialoglycoprotein, is highly expressed in many cancers and normal tissues. A neutralizing monoclonal antibody (mAb; NZ-1) can block the association between podoplanin and C-type lectin-like receptor-2 (CLEC-2) and inhibit podoplanin-induced cancer metastasis, but NZ-1 reacts with podoplanin-expressing normal cells such as lymphatic endothelial cells. In this study, we established a cancer-specific mAb (CasMab) against human podoplanin. Aberrantly glycosylated podoplanin including keratan sulfate or aberrant sialylation, which was expressed in LN229 glioblastoma cells, was used as an immunogen. The newly established LpMab-2 mAb recognized both an aberrant O-glycosylation and a Thr55-Leu64 peptide from human podoplanin. Because LpMab-2 reacted with podoplanin-expressing cancer cells but not with normal cells, as shown by flow cytometry and immunohistochemistry, it is an anti-podoplanin CasMab that is expected to be useful for molecular targeting therapy against podoplanin-expressing cancers.

| S-EPMC4118152 | biostudies-other

A broadly flavivirus cross-neutralizing monoclonal antibody that recognizes a novel epitope within the fusion loop of E protein.

Project description:Flaviviruses are a group of human pathogenic, enveloped RNA viruses that includes dengue (DENV), yellow fever (YFV), West Nile (WNV), and Japanese encephalitis (JEV) viruses. Cross-reactive antibodies against Flavivirus have been described, but most of them are generally weakly neutralizing. In this study, a novel monoclonal antibody, designated mAb 2A10G6, was determined to have broad cross-reactivity with DENV 1-4, YFV, WNV, JEV, and TBEV. Phage-display biopanning and structure modeling mapped 2A10G6 to a new epitope within the highly conserved flavivirus fusion loop peptide, the (98)DRXW(101) motif. Moreover, in vitro and in vivo experiments demonstrated that 2A10G6 potently neutralizes DENV 1-4, YFV, and WNV and confers protection from lethal challenge with DENV 1-4 and WNV in murine model. Furthermore, functional studies revealed that 2A10G6 blocks infection at a step after viral attachment. These results define a novel broadly flavivirus cross-reactive mAb with highly neutralizing activity that can be further developed as a therapeutic agent against severe flavivirus infections in humans.

| S-EPMC3019176 | biostudies-literature

Monoclonal Antibody That Recognizes Diethoxyphosphotyrosine-Modified Proteins and Peptides Independent of Surrounding Amino Acids.

Project description:Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are irreversibly inhibited by organophosphorus pesticides through formation of a covalent bond with the active site serine. Proteins that have no active site serine, for example albumin, are covalently modified on tyrosine and lysine. Chronic illness from pesticide exposure is not explained by inhibition of AChE and BChE. Our goal was to produce a monoclonal antibody that recognizes proteins diethoxyphosphorylated on tyrosine. Diethoxyphosphate-tyrosine adducts for 13 peptides were synthesized. The diethoxyphosphorylated (OP) peptides cross-linked to four different carrier proteins were used to immunize, boost, and screen mice. Monoclonal antibodies were produced with hybridoma technology. Monoclonal antibody depY was purified and characterized by ELISA, western blotting, Biacore, and Octet technology to determine binding affinity and binding specificity. DepY recognized diethoxyphosphotyrosine independent of the amino acid sequence around the modified tyrosine and independent of the identity of the carrier protein or peptide. It had an IC50 of 3 × 10-9 M in a competition assay with OP tubulin. Kd values measured by Biacore and OctetRED96 were 10-8 M for OP-peptides and 1 × 10-12 M for OP-proteins. The limit of detection measured on western blots hybridized with 0.14 μg/mL of depY was 0.025 μg of human albumin conjugated to YGGFL-OP. DepY was specific for diethoxyphosphotyrosine (chlorpyrifos oxon adduct) as it failed to recognize diethoxyphospholysine, phosphoserine, phosphotyrosine, phosphothreonine, dimethoxyphosphotyrosine (dichlorvos adduct), dimethoxyphosphoserine, monomethoxyphosphotyrosine (aged dichlorvos adduct), and cresylphosphoserine. In conclusion, a monoclonal antibody that specifically recognizes diethoxyphosphotyrosine adducts has been developed. The depY monoclonal antibody could be useful for identifying new biomarkers of OP exposure.

| S-EPMC6006506 | biostudies-literature

Staphylococcal Enterotoxin B-specific monoclonal antibody 20B1 successfully treats diverse Staphylococcus aureus infections.

Project description:BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) has become a major health threat in the United States. Staphylococcal enterotoxin B (SEB) is a potent superantigen that contributes to its virulence. High mortality and frequent failure of therapy despite available antibiotics have stimulated research efforts to develop adjunctive therapies.MethodsTreatment benefits of SEB-specific monoclonal antibody (mAb) 20B1 were investigated in mice in sepsis, superficial skin, and deep-tissue infection models.ResultsMice challenged with a SEB-producing MRSA strain developed fatal sepsis, extensive tissue skin infection, and abscess-forming deep-seeded thigh muscle infection. Animals preimmunized against SEB or treated passively with mAb 20B1 exhibited enhanced survival in the sepsis model, whereas decrease of bacterial burden was observed in the superficial skin and deep-tissue models. mAb 20B1 bound to SEB in the infected tissue and decreased abscess formation and proinflammatory cytokine levels, lymphocyte proliferation, and neutrophil recruitment.ConclusionsmAb 20B1, an SEB-neutralizing mAb, is effective against MRSA infection. mAb 20B1 protects against lethal sepsis and reduces skin tissue invasion and deep-abscess formation. The mAb penetrates well into the abscess and binds to SEB. It affects the outcome of S. aureus infection by modulating the host's proinflammatory immune response.

| S-EPMC3836467 | biostudies-literature

The monoclonal antibody SM5-1 recognizes a fibronectin variant which is widely expressed in melanoma.

Project description:BackgroundPreviously we have generated the monoclonal antibody SM5-1 by using a subtractive immunization protocol of human melanoma. This antibody exhibits a high sensitivity for primary melanomas of 99% (248/250 tested) and for metastatic melanoma of 96% (146/151 tested) in paraffin embedded sections. This reactivity is superior to the one obtained by HMB-45, anti-MelanA or anti-Tyrosinase and is comparable to anti-S100. However, as compared to anti-S100, the antibody SM5-1 is highly specific for melanocytic lesions since 40 different neoplasms were found to be negative for SM5-1 by immunohistochemistry. The antigen recognized by SM5-1 is unknown.MethodsIn order to characterize the antigen recognized by mAb SM5-1, a cDNA library was constructed from the metastatic human melanoma cell line SMMUpos in the Uni-ZAP lambda phage and screened by mAb SM5-1. The cDNA clones identified by this approach were then sequenced and subsequently analyzed.ResultsSequence analysis of nine independent overlapping clones (length 3100-5600 bp) represent fibronectin cDNA including the ED-A, but not the ED-B region which are produced by alternative splicing. The 89aa splicing variant of the IIICS region was found in 8/9 clones and the 120aa splicing variant in 1/9 clones, both of which are included in the CS1 region of fibronectin being involved in melanoma cell adhesion and spreading.ConclusionThe molecule recognized by SM5-1 is a melanoma associated FN variant expressed by virtually all primary and metastatic melanomas and may play an important role in melanoma formation and progression. This antibody is therefore not only of value in immunohistochemistry, but potentially also for diagnostic imaging and immunotherapy.

| S-EPMC1351261 | biostudies-literature

Discovery and Characterization of a Thioesterase-Specific Monoclonal Antibody That Recognizes the 6-Deoxyerythronolide B Synthase.

Project description:Assembly line polyketide synthases (PKSs) are large multimodular enzymes responsible for the biosynthesis of diverse antibiotics in bacteria. Structural and mechanistic analysis of these megasynthases can benefit from the discovery of reagents that recognize individual domains or linkers in a site-specific manner. Monoclonal antibodies not only have proven themselves as premier tools in analogous applications but also have the added benefit of constraining the conformational flexibility of their targets in unpredictable but often useful ways. Here we have exploited a library based on the naïve human antibody repertoire to discover a Fab (3A6) that recognizes the terminal thioesterase (TE) domain of the 6-deoxyerythronolide B synthase with high specificity. Biochemical assays were used to verify that 3A6 binding does not inhibit enzyme turnover. The co-crystal structure of the TE-3A6 complex was determined at 2.45 Å resolution, resulting in atomic characterization of this protein-protein recognition mechanism. Fab binding had minimal effects on the structural integrity of the TE. In turn, these insights were used to interrogate via small-angle X-ray scattering the solution-phase conformation of 3A6 complexed to a catalytically competent PKS module and bimodule. Altogether, we have developed a high-affinity monoclonal antibody tool that recognizes the TE domain of the 6-deoxyerythronolide B synthase while maintaining its native function.

| S-EPMC6424575 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data