Construction and Characterization of a Single-Chain Variable Fragment (scFv) for the Detection of Cry1Ab and Cry1Ac Toxins from the Anti-Cry1Ab Monoclonal Antibody

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.

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

Biomaterials Science ◽

10.1039/d0bm01903h ◽

2021 ◽

Author(s):

Francisco J. Reche-Perez ◽

Simona Plesselova ◽

Eduardo De los Reyes-Berbel ◽

Mariano Ortega-Muñoz ◽

F. Javier Lopez-Jaramillo ◽

...

Keyword(s):

Monoclonal Antibody ◽

Targeted Delivery ◽

Specific Binding ◽

Protein A ◽

Antibody Fragments ◽

Single Chain Variable Fragment ◽

Single Chain ◽

Binding Properties ◽

Single Chain Variable Fragments ◽

Selective Delivery

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...

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Characterization of a Lipopolysaccharide-Targeted Monoclonal Antibody and Its Variable Fragments as Candidates for Prophylaxis against the Obligate Intracellular Bacterial Pathogen Coxiella burnetii

Infection and Immunity ◽

10.1128/iai.01695-14 ◽

2014 ◽

Vol 82 (11) ◽

pp. 4530-4541 ◽

Cited By ~ 6

Author(s):

Ying Peng ◽

Laura Schoenlaub ◽

Alexandra Elliott ◽

William J. Mitchell ◽

Guoquan Zhang

Keyword(s):

Monoclonal Antibody ◽

Coxiella Burnetii ◽

Natural Infection ◽

Bacterial Pathogen ◽

Passive Transfer ◽

Single Chain Variable Fragment ◽

Single Chain ◽

Fab Fragment ◽

Content Type ◽

Aerosol Infection

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.

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