scholarly journals Phage Display Selection of an Anti-Idiotype-Antibody with Broad-Specificity to Deoxynivalenol Mycotoxins

Toxins ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Janne Leivo ◽  
Markus Vehniäinen ◽  
Urpo Lamminmäki
Keyword(s):  
In Vitro Selection ◽  
Specific Binding ◽  
Binding Properties ◽  
Phage Displays ◽  
Synthetic Antibody ◽  
Wide Range ◽  
Antibody Libraries ◽  
Rapid Generation ◽  
Selection Of

The use of synthetic antibody libraries and phage displays provides an efficient and robust method for the generation of antibodies against a wide range of targets with highly specific binding properties. As the in vitro selection conditions can be easily controlled, these methods enable the rapid generation of binders against difficult targets such as toxins and haptens. In this study, we used deoxynivalenol mycotoxin as a target to generate anti-idiotype-antibodies with unique binding properties from synthetic antibody libraries. The binding of the selected anti-idiotype antibodies can be efficiently inhibited with the addition of free isoforms of deoxynivalenol. The antibody was consecutively used to develop deoxynivalenol-specific ELISA and TRF-immunoassays, which can detect deoxynivalenol and two of the most common metabolic isoforms in the range of 78–115 ng/mL.

scholarly journals A cell-free nanobody engineering platform rapidly generates SARS-CoV-2 neutralizing nanobodies

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xun Chen ◽  
Matteo Gentili ◽  
Nir Hacohen ◽  
Aviv Regev
Keyword(s):  
In Vitro Selection ◽  
Affinity Maturation ◽  
Antibody Engineering ◽  
Pseudotyped Virus ◽  
Receptor Binding Domain ◽  
Computational Pipeline ◽  
A Cell ◽  
Rapid Generation ◽  
Selection Of

AbstractAntibody engineering technologies face increasing demands for speed, reliability and scale. We develop CeVICA, a cell-free nanobody engineering platform that uses ribosome display for in vitro selection of nanobodies from a library of 1011 randomized sequences. We apply CeVICA to engineer nanobodies against the Receptor Binding Domain (RBD) of SARS-CoV-2 spike protein and identify >800 binder families using a computational pipeline based on CDR-directed clustering. Among 38 experimentally-tested families, 30 are true RBD binders and 11 inhibit SARS-CoV-2 pseudotyped virus infection. Affinity maturation and multivalency engineering increase nanobody binding affinity and yield a virus neutralizer with picomolar IC50. Furthermore, the capability of CeVICA for comprehensive binder prediction allows us to validate the fitness of our nanobody library. CeVICA offers an integrated solution for rapid generation of divergent synthetic nanobodies with tunable affinities in vitro and may serve as the basis for automated and highly parallel nanobody engineering.

scholarly journals In vitro selection of l-DNA aptamers that bind a structured d-RNA molecule

2020 ◽  
Vol 48 (4) ◽  
pp. 1669-1680 ◽  
Author(s):  
Sougata Dey ◽  
Jonathan T Sczepanski
Keyword(s):  
In Vitro Selection ◽  
Rna Binding ◽  
Rna Aptamers ◽  
Dna Aptamers ◽  
Binding Properties ◽  
Rna Molecules ◽  
Dna And Rna ◽  
Selection Of

Abstract The development of structure-specific RNA binding reagents remains a central challenge in RNA biochemistry and drug discovery. Previously, we showed in vitro selection techniques could be used to evolve l-RNA aptamers that bind tightly to structured d-RNAs. However, whether similar RNA-binding properties can be achieved using aptamers composed of l-DNA, which has several practical advantages compared to l-RNA, remains unknown. Here, we report the discovery and characterization of the first l-DNA aptamers against a structured RNA molecule, precursor microRNA-155, thereby establishing the capacity of DNA and RNA molecules of the opposite handedness to form tight and specific ‘cross-chiral’ interactions with each other. l-DNA aptamers bind pre-miR-155 with low nanomolar affinity and high selectivity despite the inability of l-DNA to interact with native d-RNA via Watson–Crick base pairing. Furthermore, l-DNA aptamers inhibit Dicer-mediated processing of pre-miRNA-155. The sequence and structure of l-DNA aptamers are distinct from previously reported l-RNA aptamers against pre-miR-155, indicating that l-DNA and l-RNA interact with the same RNA sequence through unique modes of recognition. Overall, this work demonstrates that l-DNA may be pursued as an alternative to l-RNA for the generation of RNA-binding aptamers, providing a robust and practical approach for targeting structured RNAs.

The Effects of Shock Vancomycin Concentrations on the Formation of Heteroresistance in Staphylococcus aureus

2020 ◽  
Vol 65 (9-10) ◽  
pp. 3-7
Author(s):  
V. V. Gostev ◽  
Yu. V. Sopova ◽  
O. S. Kalinogorskaya ◽  
M. E. Velizhanina ◽  
I. V. Lazareva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Vitro Selection ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
High Concentration ◽  
Short Term ◽  
High Concentrations ◽  
Selection Of ◽  
Selection Of Resistance ◽  
Test Cultures

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.

Wheat Germ Cell-Free Translation System as a Tool for In vitro Selection of Functional Proteins

2002 ◽  
Vol 5 (6) ◽  
pp. 473-480
Author(s):  
Bentham Science Publisher A.N. Alexandrov ◽  
Bentham Science Publisher V.Yu. Alakhov ◽  
Bentham Science Publisher A.I. Miroshnikov
Keyword(s):  
Germ Cell ◽  
Wheat Germ ◽  
In Vitro Selection ◽  
Translation System ◽  
Free Translation ◽  
Selection Of

In vitro Selection of Ligase Ribozymes Containing 2'-Amino Groups

2000 ◽  
Vol 15 (4) ◽  
pp. 297-308 ◽  
Author(s):  
NAOZUMI TERAMOTO ◽  
YUKIO IMANISHI ◽  
YOSHIHIRO ITO
Keyword(s):  
In Vitro Selection ◽  
Amino Groups ◽  
Selection Of

scholarly journals In vitro and in vivo inhibition of malaria parasite infection by monoclonal antibodies against Plasmodium falciparum circumsporozoite protein (CSP)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Merricka C. Livingstone ◽  
Alexis A. Bitzer ◽  
Alish Giri ◽  
Kun Luo ◽  
Rajeshwer S. Sankhala ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Monoclonal Antibodies ◽  
Disease Burden ◽  
Vaccine Candidate ◽  
Specific Binding ◽  
Circumsporozoite Protein ◽  
Target Epitope ◽  
Selection Of

AbstractPlasmodium falciparum malaria contributes to a significant global disease burden. Circumsporozoite protein (CSP), the most abundant sporozoite stage antigen, is a prime vaccine candidate. Inhibitory monoclonal antibodies (mAbs) against CSP map to either a short junctional sequence or the central (NPNA)n repeat region. We compared in vitro and in vivo activities of six CSP-specific mAbs derived from human recipients of a recombinant CSP vaccine RTS,S/AS01 (mAbs 317 and 311); an irradiated whole sporozoite vaccine PfSPZ (mAbs CIS43 and MGG4); or individuals exposed to malaria (mAbs 580 and 663). RTS,S mAb 317 that specifically binds the (NPNA)n epitope, had the highest affinity and it elicited the best sterile protection in mice. The most potent inhibitor of sporozoite invasion in vitro was mAb CIS43 which shows dual-specific binding to the junctional sequence and (NPNA)n. In vivo mouse protection was associated with the mAb reactivity to the NANPx6 peptide, the in vitro inhibition of sporozoite invasion activity, and kinetic parameters measured using intact mAbs or their Fab fragments. Buried surface area between mAb and its target epitope was also associated with in vivo protection. Association and disconnects between in vitro and in vivo readouts has important implications for the design and down-selection of the next generation of CSP based interventions.

scholarly journals Back Cover: In Vitro Selection of a DNA Aptamer Targeting Degraded Protein Fragments for Biosensing (Angew. Chem. Int. Ed. 20/2020)

2020 ◽  
Vol 59 (20) ◽  
pp. 7968-7968
Author(s):  
Meng Liu ◽  
Jiayi Wang ◽  
Yangyang Chang ◽  
Qiang Zhang ◽  
Dingran Chang ◽  
...  
Keyword(s):  
In Vitro Selection ◽  
Dna Aptamer ◽  
Protein Fragments ◽  
Back Cover ◽  
Selection Of
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