scholarly journals Structural and functional characterization of a novel scFv anti-HSP60 of Strongyloides sp.

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Marcelo Arantes Levenhagen ◽  
Fabiana de Almeida Araújo Santos ◽  
Patrícia Tiemi Fujimura ◽  
Ana Paula Carneiro ◽  
Julia Maria Costa-Cruz ◽  
...  
Keyword(s):  
Phage Display ◽  
Functional Characterization ◽  
Positive Likelihood Ratio ◽  
Antibody Fragment ◽  
The Body ◽  
Enzyme Linked Immunosorbent Assay ◽  
Heat Shock Protein 60 ◽  
Single Chain ◽  
Serum Samples ◽  
Antigenic Fraction

Abstract Phage display is a powerful technology that selects specific proteins or peptides to a target. We have used Phage Display to select scFv (single-chain variable fragment) clones from a combinatorial library against total proteins of Strongyloides venezuelensis. After scFv characterization, further analysis demonstrated that this recombinant fragment of antibody was able to bind to an S. venezuelensis antigenic fraction of ~65 kDa, present in the body periphery and digestive system of infective larvae (L3), as demonstrated by immunofluorescence. Mass spectrometry results followed by bioinformatics analysis showed that this antigenic fraction was a heat shock protein 60 (HSP60) of Strongyloides sp. The selected scFv was applied in serodiagnosis by immune complexes detection in serum samples from individuals with strongyloidiasis using a sandwich enzyme-linked immunosorbent assay (ELISA), showing sensitivity of 97.5% (86.84–99.94), specificity of 98.81 (93.54–99.97), positive likelihood ratio of 81.60 and an area under the curve of 0.9993 (0.9973–1.000). Our study provided a novel monoclonal scFv antibody fragment which specifically bound to HSP60 of Strongyloides sp. and was applied in the development of an innovative serodiagnosis method for the human strongyloidiasis.

Screening of Single-Chain Variable Fragments against TSP50 from a Phage Display Antibody Library and Their Expression as Soluble Proteins

2006 ◽  
Vol 11 (5) ◽  
pp. 546-552 ◽  
Author(s):  
Jingyan Wei ◽  
Yang Liu ◽  
Songchuan Yang ◽  
Junjie Xu ◽  
Hangtian Kong ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Phage Display ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sandwich Elisa ◽  
Sodium Dodecyl ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Library ◽  
Single Chain ◽  
Single Chain Variable Fragments ◽  
Phage Display Antibody

A novel gene, testes-specific protease 50 ( TSP50), is abnormally activated and differentially expressed in most patients with breast cancer, suggesting it as a novel biomarker for this disease. The possibility that TSP50 may be an oncogene is presently under investigation. In this study, the single-chain variable fragments (scFvs) against TSP50 were panned from a phage display antibody library using TSP50-specific peptide, pep-50, as a target antigen. After 4 rounds of panning, 3 clones (A1, A11, and C8) from the library were verified to show strong binding affinities for TSP50 by enzyme-linked immunosorbent assay (ELISA) and to contain the variable region genes of the light and heavy chains of scFv antibodies but different complementary determining regions by sequencing. The genes of scFv-A1 and scFv-A11 were cloned into expression vector pPELB and successfully expressed as a soluble protein in Escherichia coli Rosetta. The yields of expressions were about 4.0 to 5.0 mg of protein from 1 L of culture. The expressed proteins were purified by a 2-step procedure consisting of ion-exchange chromatography, followed by immobilized metal affinity chromatography. The purified proteins were shown a single band at the position of 31 KDa on sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Sandwich ELISA demonstrated that the expressed scFv proteins were able to specifically react with pep-50, laying a foundation for the investigation of the function of TSP50 in the development and treatment of breast cancer.

scholarly journals Subtractive Phage Display Selection from Canine Visceral Leishmaniasis Identifies Novel Epitopes That Mimic Leishmania infantum Antigens with Potential Serodiagnosis Applications

2013 ◽  
Vol 21 (1) ◽  
pp. 96-106 ◽  
Author(s):  
Lourena E. Costa ◽  
Mayara I. S. Lima ◽  
Miguel A. Chávez-Fumagalli ◽  
Daniel Menezes-Souza ◽  
Vivian T. Martins ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Phage Display ◽  
Leishmania Infantum ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Phage Display Technology ◽  
Predictive Values ◽  
Content Type ◽  
Phage Elisa

ABSTRACTVisceral leishmaniasis (VL) is a zoonotic disease that is endemic to Brazil, where dogs are the main domestic parasite reservoirs, and the percentages of infected dogs living in regions where canine VL (CVL) is endemic have ranged from 10% to 62%. Despite technological advances, some problems have been reported with CVL serodiagnosis. The present study describes a sequential subtractive selection through phage display technology from polyclonal antibodies of negative and positive sera that resulted in the identification of potential bacteriophage-fused peptides that were highly sensitive and specific to antibodies of CVL. A negative selection was performed in which phage clones were adhered to purified IgGs from healthy andTrypanosoma cruzi-infected dogs to eliminate cross-reactive phages. The remaining supernatant nonadhered phages were submitted to positive selection against IgG from the blood serum of dogs that were infected withLeishmania infantum. Phage clones that adhered to purified IgGs from the CVL-infected serum samples were selected. Eighteen clones were identified and their reactivities tested by a phage enzyme-linked immunosorbent assay (phage-ELISA) against the serum samples from infected dogs (n= 31) compared to those from vaccinated dogs (n= 21), experimentally infected dogs with cross-reactive parasites (n= 23), and healthy controls (n= 17). Eight clones presented sensitivity, specificity, and positive and negative predictive values of 100%, and they showed no cross-reactivity withT. cruzi- orEhrlichia canis-infected dogs or with dogs vaccinated with two different commercial CVL vaccines in Brazil. Our study identified eight mimotopes ofL. infantumantigens with 100% accuracy for CVL serodiagnosis. The use of these mimotopes by phage-ELISA proved to be an excellent assay that was reproducible, simple, fast, and inexpensive, and it can be applied in CVL-monitoring programs.

scholarly journals Single-Chain Antibody Fragment Specific for Plasmodium vivax Duffy Binding Protein

2007 ◽  
Vol 14 (6) ◽  
pp. 726-731 ◽  
Author(s):  
So-Hee Kim ◽  
Seung-Young Hwang ◽  
Yong-Seok Lee ◽  
In-Hak Choi ◽  
Sae-Gwang Park ◽  
...  
Keyword(s):  
Phage Display ◽  
Plasmodium Vivax ◽  
Binding Protein ◽  
Antibody Fragment ◽  
Neutralizing Antibody ◽  
Active Immunization ◽  
Single Chain ◽  
Single Chain Antibody ◽  
Duffy Binding Protein ◽  
Erythrocyte Binding

ABSTRACT Phage display of single-chain variable fragment (scFv) antibodies is a powerful tool for selecting important, useful, and specific human antibodies. We constructed a library from three patients infected with Plasmodium vivax. Panning on recombinant PvRII enriched a population of scFvs that recognized region II of the P. vivax Duffy binding protein (DBP). Three clones of scFvs that reacted with PvRII were selected, and their biological functions were analyzed. These scFvs inhibited erythrocyte binding to DBP. Clone SFDBII92 had the greatest affinity (dissociation constant = 3.62 × 10−8 M) and the greatest inhibition activity (50% inhibitory concentration ≈ 2.9 μg/ml) to DBP. Thus, we demonstrated that human neutralizing antibody could be made from malaria patients using phage display and that these neutralizing scFvs should prove valuable for developing both passive and active immunization strategies based on DBP.

scholarly journals Selection of single chain antibody fragments binding to the extracellular domain of 4-1BB receptor by phage display technology

Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769592 ◽  
Author(s):  
Salman Bagheri ◽  
Mehdi Yousefi ◽  
Elmira Safaie Qamsari ◽  
Farhad Riazi-Rad ◽  
Mohsen Abolhassani ◽  
...  
Keyword(s):  
Phage Display ◽  
Immunosorbent Assay ◽  
Specific Binding ◽  
Interleukin 2 ◽  
Extracellular Domain ◽  
Surface Glycoprotein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Single Chain ◽  
Single Chain Variable Fragments ◽  
Selection Of

The 4-1BB is a surface glycoprotein that pertains to the tumor necrosis factor–receptor family. There is compelling evidence suggesting important roles for 4-1BB in the immune response, including cell activation and proliferation and also cytokine induction. Because of encouraging results of different agonistic monoclonal antibodies against 4-1BB in the treatment of cancer, infectious, and autoimmune diseases, 4-1BB has been suggested as an attractive target for immunotherapy. In this study, single chain variable fragment phage display libraries, Tomlinson I+J, were screened against specific synthetic oligopeptides (peptides I and II) designed from 4-1BB extracellular domain. Five rounds of panning led to selection of four 4-1BB specific single chain variable fragments (PI.12, PI.42, PII.16, and PII.29) which showed specific reaction to relevant peptides in phage enzyme-linked immunosorbent assay. The selected clones were successfully expressed in Escherichia coli Rosetta-gami 2, and their expression was confirmed by western blot analysis. Enzyme-linked immunosorbent assay experiments indicated that these antibodies were able to specifically recognize 4-1BB without any cross-reactivity with other antigens. Flow cytometry analysis demonstrated an acceptable specific binding of the single chain variable fragments to 4-1BB expressed on CCRF-CEM cells, while no binding was observed with an irrelevant antibody. Anti-4-1BB single chain variable fragments enhanced surface CD69 expression and interleukin-2 production in stimulated CCRF-CEM cells which confirmed the agonistic effect of the selected single chain variable fragments. The data from this study have provided a rationale for further experiments involving the biological functions of anti-4-1BB single chain variable fragments in future studies.

scholarly journals Soluble Expression of a Neo2/15-Conjugated Single Chain Fv against PD-L1 in Escherichia coli

2022 ◽  
Vol 44 (1) ◽  
pp. 301-308
Author(s):  
Sun-Hee Kim ◽  
Hee-Jin Jeong
Keyword(s):  
Fusion Protein ◽  
Expression System ◽  
Antibody Fragment ◽  
Therapeutic Index ◽  
High Yield ◽  
Soluble Form ◽  
Enzyme Linked Immunosorbent Assay ◽  
Single Chain ◽  
Single Chain Fv ◽  
Programmed Death

Immunocytokines, antibody-cytokine fusion proteins, have the potential to improve the therapeutic index of cytokines by delivering the cytokine to the site of localized tumor cells using antibodies. In this study, we produced a recombinant anti-programmed death-ligand 1 (PD-L1) scFv, an antibody fragment against PD-L1 combined with a Neo2/15, which is an engineered interleukin with superior function using an E. coli expression system. We expressed the fusion protein in a soluble form and purified it, resulting in high yield and purity. The high PD-L1-binding efficiency of the fusion protein was confirmed via enzyme-linked immunosorbent assay, suggesting the application of this immunocytokine as a cancer-related therapeutic agent.

scholarly journals Serum Glutamate Is a Predictor for the Diagnosis of Multiple Sclerosis

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Gheyath Al Gawwam ◽  
Inas K. Sharquie
Keyword(s):  
Multiple Sclerosis ◽  
Area Under The Curve ◽  
The Body ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Operating Characteristics ◽  
Serum Samples ◽  
Elisa Technique ◽  
Autoimmune Demyelination ◽  
Serum Glutamate

One neurotransmitter, glutamate, has been implicated in the autoimmune demyelination seen in multiple sclerosis (MS). Glutamate is present in many tissues in the body, so consideration should be given to whether the serum level of glutamate is likely well correlated with the activity of the disease. This research aimed to compare the serum glutamate levels from patients diagnosed with MS with those from an age-matched control population. A review of this data could shed light upon whether the serum testing of glutamate using Enzyme-Linked Immunosorbent Assay (ELISA) is a reliable indicator of MS activity. Serum samples were obtained from 55 patients with different patterns of MS and from 25 healthy adults as a control group. The ELISA technique was used to determine the glutamate levels in the serum samples. The mean serum glutamate level for patients with MS was1.318±0.543 nmol/ml and that of the controls was0.873±0.341 nmol/ml. The serum glutamate levels showed an area under the curve via the receiver operating characteristics (ROC) of 0.738, which was significant (pvalue = 0.001). The present study is the first to establish a strong connection between the serum glutamate levels and MS patients, where there was statistically significant elevation of serum glutamate in MS patients; hence this elevation might be used as a monitor to help in the diagnosis of MS patients.

scholarly journals Rapid Isolation of a Single-Chain Antibody against the Cyanobacterial Toxin Microcystin-LR by Phage Display and Its Use in the Immunoaffinity Concentration of Microcystins from Water

2002 ◽  
Vol 68 (11) ◽  
pp. 5288-5295 ◽  
Author(s):  
Jacqui McElhiney ◽  
Mathew Drever ◽  
Linda A. Lawton ◽  
Andy J. Porter
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Phage Display ◽  
High Performance ◽  
Recombinant Antibody ◽  
World Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Single Chain ◽  
Single Chain Antibody ◽  
Cyanobacterial Toxin

ABSTRACT A naïve (unimmunized) human semisynthetic phage display library was employed to isolate recombinant antibody fragments against the cyanobacterial hepatotoxin microcystin-LR. Selected antibody scFv genes were cloned into a soluble expression vector and expressed in Escherichia coli for characterization against purified microcystin-LR by competition enzyme-linked immunosorbent assay (ELISA). The most sensitive single-chain antibody (scAb) isolated was capable of detecting microcystin-LR at levels below the World Health Organization limit in drinking water (1 μg liter−1) and cross-reacted with three other purified microcystin variants (microcystin-RR, -LW, and -LF) and the related cyanotoxin nodularin. Extracts of the cyanobacterium Microcystis aeruginosa were assayed by ELISA, and quantifications of microcystins in toxic samples showed good correlation with analysis by high-performance liquid chromatography. Immobilized scAb was also used to prepare immunoaffinity columns, which were assessed for the ability to concentrate microcystin-LR from water for subsequent analysis by high-performance liquid chromatography. Anti-microcystin-LR scAb was immobilized on columns via a hexahistidine tag, ensuring maximum exposure of antigen binding sites, and the performance of the columns was evaluated by directly applying 150 ml of distilled water spiked with 4 μg of purified microcystin-LR. The procedure was simple, and a recovery rate of 94% was achieved following elution in 1 ml of 100% methanol. Large-scale, low-cost production of anti-microcystin-LR scAb in E. coli is an exciting prospect for the development of biosensors and on-line monitoring systems for microcystins and will also facilitate a range of immunoaffinity applications for the cleanup and concentration of these toxins from environmental samples.

scholarly journals Generation and Characterization of Human Monoclonal scFv Antibodies against Helicobacter pylori Antigens

2002 ◽  
Vol 70 (8) ◽  
pp. 4158-4164 ◽  
Author(s):  
Nicole Reiche ◽  
Andreas Jung ◽  
Thomas Brabletz ◽  
Tanja Vater ◽  
Thomas Kirchner ◽  
...  
Keyword(s):  
Immune Response ◽  
Helicobacter Pylori ◽  
Phage Display ◽  
Humoral Immune Response ◽  
Vaccine Development ◽  
Enzyme Linked Immunosorbent Assay ◽  
Single Chain ◽  
Humoral Immune ◽  
Single Chain Fv ◽  
H Pylori

ABSTRACT Infection with Helicobacter pylori is chronic despite a vigorous cellular and humoral immune response and causes severe pathology in some patients. In this study, phage display was used as a new approach in order to investigate the role of the host's humoral immune response in the pathogenesis of H. pylori gastritis. Human monoclonal single-chain Fv (scFv) antibody fragments against H. pylori cell lysate and the H. pylori urease were isolated from an immune phage display library, constructed from peripheral blood lymphocytes of an H. pylori-infected patient. After affinity selection, 23% of the clones tested showed binding activity against a lysate of the H. pylori Sydney strain in enzyme-linked immunosorbent assay (ELISA) and 9% bound the H. pylori urease. Further characterization by PCR-fingerprint analysis and sequencing revealed that two closely related H. pylori binders and one antiurease scFv could be isolated. The selected scFvs were highly specific as analyzed by ELISA and immunoblots using various bacterial lysates and recombinant proteins. Analysis of the humoral immune response following H. pylori infection using human monoclonal antibodies might contribute to a better understanding of the pathogenesis of the disease. Moreover, using immune phage display libraries, it might be possible for relevant epitopes of H. pylori antigens to be determined, which might be of use for vaccine development.

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