scholarly journals Single Chain Variable Fragment Fused to Maltose Binding Protein: A Modular Nanocarrier Platform for the Targeted Delivery of Antitumorals

2021 ◽  
Author(s):  
Francisco J. Reche-Perez ◽  
Simona Plesselova ◽  
Eduardo De los Reyes-Berbel ◽  
Mariano Ortega-Muñoz ◽  
F. Javier Lopez-Jaramillo ◽  
...  

The use of the specific binding properties of monoclonal antibody fragments such as single-chain variable fragments (ScFv) for the selective delivery of antitumor therapeutics for cancer cells is attractive due...

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rodrigo Barbosa de Aguiar ◽  
Tábata de Almeida da Silva ◽  
Bruno Andrade Costa ◽  
Marcelo Ferreira Marcondes Machado ◽  
Renata Yoshiko Yamada ◽  
...  

AbstractSingle-chain variable fragments (scFvs) are small-sized artificial constructs composed of the immunoglobulin heavy and light chain variable regions connected by a peptide linker. We have previously described an anti-fibroblast growth factor 2 (FGF2) immunoglobulin G (IgG) monoclonal antibody (mAb), named 3F12E7, with notable antitumor potential revealed by preclinical assays. FGF2 is a known angiogenesis-associated molecule implicated in tumor progression. In this report, we describe a recombinant scFv format for the 3F12E7 mAb. The results demonstrate that the generated 3F12E7 scFv, although prone to aggregation, comprises an active anti-FGF2 product that contains monomers and small oligomers. Functionally, the 3F12E7 scFv preparations specifically recognize FGF2 and inhibit tumor growth similar to the corresponding full-length IgG counterpart in an experimental model. In silico molecular analysis provided insights into the aggregation propensity and the antigen-recognition by scFv units. Antigen-binding determinants were predicted outside the most aggregation-prone hotspots. Overall, our experimental and prediction dataset describes an scFv scaffold for the 3F12E7 mAb and also provides insights to further engineer non-aggregated anti-FGF2 scFv-based tools for therapeutic and research purposes.


2014 ◽  
Vol 82 (11) ◽  
pp. 4530-4541 ◽  
Author(s):  
Ying Peng ◽  
Laura Schoenlaub ◽  
Alexandra Elliott ◽  
William J. Mitchell ◽  
Guoquan Zhang

ABSTRACTOur previous study demonstrated that treatment ofCoxiella burnetiiwith the phase I lipopolysaccharide (PI-LPS)-targeted monoclonal antibody (MAb) 1E4 significantly inhibitedC. burnetiiinfection in mice, suggesting that 1E4 is a protective MAb. To determine whether passive transfer of antibodies (Abs) can provide protection againstC. burnetiinatural infection, we examined if passive transfer of 1E4 would protect SCID mice againstC. burnetiiaerosol infection. The results indicated that 1E4 conferred significant protection against aerosolizedC. burnetii, suggesting that 1E4 may be useful for preventingC. burnetiinatural infection. To further understand the mechanisms of 1E4-mediated protection and to test the possibility of using humanized 1E4 to preventC. burnetiiinfection, we examined whether the Fab fragment of 1E4 (Fab1E4), a recombinant murine single-chain variable fragment (muscFv1E4), and a humanized single-chain variable fragment (huscFv1E4) retained the ability of 1E4 to inhibitC. burnetiiinfection. The results indicated that Fab1E4, muscFv1E4, and huscFv1E4 were able to inhibitC. burnetiiinfection in mice but that their ability to inhibitC. burnetiiinfection was lower than that of 1E4. In addition, treatment ofC. burnetiiwith Fab1E4, muscFv1E4, or huscFv1E4 can blockC. burnetiiinfection of macrophages. Interestingly, treatment ofC. burnetiiwith huscFv1E4 can significantly reduceC. burnetiiinfectivity in human macrophages. This report provides the first evidence to demonstrate that the humanized variable fragments of an LPS-specific MAb can neutralizeC. burnetiiinfection and appears to be a promising step toward the potential use of a humanized MAb as emergency prophylaxis againstC. burnetiiexposure.


2020 ◽  
Vol 21 (2) ◽  
pp. 492 ◽  
Author(s):  
Pharaoh Fellow Mwale ◽  
Chi-Hsin Lee ◽  
Liang-Tzung Lin ◽  
Sy-Jye Leu ◽  
Yun-Ju Huang ◽  
...  

Zika virus (ZIKV) is a new and emerging virus that has caused outbreaks worldwide. The virus has been linked to congenital neurological malformations in neonates and Guillain–Barré syndrome in adults. Currently there are no effective vaccines available. As a result, there is a great need for ZIKV treatment. In this study, we developed single chain variable fragment (scFv) antibodies that target the ZIKV envelope protein using phage display technology. We first induced an immune response in white leghorn laying hens against the ZIKV envelope (E) protein. Chickens were immunized and polyclonal immunoglobulin yolk (IgY) antibodies were extracted from egg yolks. A high-level titer of anti-ZIKV_E IgY antibodies was detected using enzyme-linked immunosorbent assay (ELISA) after the third immunization. The titer persisted for at least 9 weeks. We constructed two antibody libraries that contained 5.3 × 106 and 4.5 × 106 transformants. After biopanning, an ELISA phage assay confirmed the enrichment of specific clones. We randomly selected 26 clones that expressed ZIKV scFv antibodies and classified them into two groups, short-linker and long-linker. Of these, four showed specific binding activities toward ZIKV_E proteins. These data suggest that the polyclonal and monoclonal scFv antibodies have the diagnostic or therapeutic potential for ZIKV.


Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769592 ◽  
Author(s):  
Salman Bagheri ◽  
Mehdi Yousefi ◽  
Elmira Safaie Qamsari ◽  
Farhad Riazi-Rad ◽  
Mohsen Abolhassani ◽  
...  

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.


2019 ◽  
Author(s):  
Michael Fairhead ◽  
Charlotta Preger ◽  
Edvard Wigren ◽  
Claire Strain-Damerell ◽  
Elena Ossipova ◽  
...  

AbstractAntibody fragments have great potential as crystallization chaperones for structural biology due to their ability to either stabilise targets, trap certain conformations and/or promote crystal packing. Here we present an example of using a single-chain variable fragment (scFv) to determine the previously unsolved structure of the multidomain protein SP140. This nuclear leukocyte-specific protein contains domains related to chromatin-mediated gene expression and has been implicated in various disease states. The structure of two of the domains (PHD-bromodomain) was solved by crystallizing them as a complex with a scFv generated by phage display technology. SP140 maintains a similar overall fold to previous PHD-bromodomains and the scFv CDR loops predominately interact with the PHD, while the framework regions of the scFv makes numerous interactions with the bromodomain. Analysis of our and other complex structures suggest various protein engineering strategies that might be employed to improve the usefulness of scFvs as crystallization chaperones.


2016 ◽  
Vol 64 (1) ◽  
Author(s):  
Róza Sawicka ◽  
Paweł Siedlecki ◽  
Barbara Kalenik ◽  
Jan P Radomski ◽  
Violetta Sączyńska ◽  
...  

Hemagglutinin (HA), as a major surface antigen of influenza virus, is widely used as a target for production of neutralizing antibodies. Monoclonal antibody, mAb6-9-1, directed against HA of highly pathogenic avian influenza virus A/swan/Poland/305-135V08/2006(H5N1) was purified from mouse hybridoma cells culture and characterized. The antigenic specificity of mAb6-9-1 was verified by testing its cross-reactivity with several variants of HA. The mimotopes recognized by mAb6-9-1 were selected from two types of phage display libraries. The comparative structural model of the HA variant used for antibody generation was developed to further facilitated epitope mapping. Based on the sequences of the affinity-selected polypeptides and the structural model of HA the epitope has been located to the region near the receptor binding site (RBS). Such localization of the epitope recognized by mAb6-9-1 is in concordance with its moderate hemagglutination inhibition activity and its antigenic specificity. Additionally, total RNA from hybridoma cells secreting mAb6-9-1 was used for obtaining two variants of cDNA encoding recombinant single-chain variable fragment (scFv) antibody. To ensure high production level and solubility in bacterial expression system, the scFv fragments were produced as chimeric proteins in fusion with thioredoxin or displayed on a phage surface after cloning into the phagemid vector. Specificity and affinity of the recombinant soluble and phage-bound scFv were assayed by suitable variants of ELISA test. The observed slight differences in specificity are discussed.


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