Screening of anti-idiotypic domain antibody from phage library for development of Bt Cry1A simulants

AbstractNatural dengue virus (DENV) infections occur by mosquito bite but how the inoculation route affects the humoral immune response is unknown. We serologically profiled 20 non-human primates (NHP) from a prior study of DENV1 infection where animals were inoculated by mosquito (N = 10) or subcutaneous injection (N = 10). Using a comprehensive, densely tiled and highly redundant pan-flavivirus programmable phage library containing 91,562 overlapping 62 amino acid peptides, we produced a high-resolution map of linear peptide sequences enriched during DENV seroconversion. Profiles in mosquito-inoculated and subcutaneously-inoculated animals were similar up to 90 days after primary infection, but diverged at 1 year with differences in sero-reactivity in the Envelope (E; residues 215–406; p < 0.08), and Nonstructural-3 (NS3; residues 549–615; p < 0.05) proteins in mosquito-inoculated versus subcutaneously-inoculated animals. Within the E protein, residues 339–384 in domain III accounted for > 99% of the observed sero-reactivity difference. Antibody breadth did not vary by mode of inoculation. The differential reactivity to E domain III seen by phage display validated orthogonally by ELISA, but did not correlate with late neutralization titers. Serological profiling of humoral immune responses to DENV infection in NHP by programmable phage display demonstrated durable differences in sero-reactivity by route of inoculation.

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Production, characterization and in-vitro applications of single-domain antibody against thyroglobulin selected from novel T7 phage display library

Journal of Immunological Methods ◽

10.1016/j.jim.2021.112990 ◽

2021 ◽

Vol 492 ◽

pp. 112990

Author(s):

Jothivel Kumarasamy ◽

Samar Kumar Ghorui ◽

Chandrakala Gholve ◽

Bharti Jain ◽

Yogesh Dhekale ◽

...

Keyword(s):

Phage Display ◽

Phage Display Library ◽

Single Domain ◽

Single Domain Antibody ◽

Domain Antibody ◽

T7 Phage Display ◽

T7 Phage

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Isolation and characterizations of a novel recombinant scFv antibody against exotoxin A of Pseudomonas aeruginosa

BMC Infectious Diseases ◽

10.1186/s12879-021-05969-0 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Zahra Shadman ◽

Safar Farajnia ◽

Mohammad Pazhang ◽

Mohammadreza Tohidkia ◽

Leila Rahbarnia ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Virulence Factors ◽

High Reactivity ◽

Scfv Antibody ◽

Phage Library ◽

Human Antibody ◽

Exotoxin A ◽

Phage Elisa ◽

Human Scfv ◽

Domain I

Abstract Background Pseudomonas aeruginosa is the leading cause of nosocomial infections, especially in people with a compromised immune system. Targeting virulence factors by neutralizing antibodies is a novel paradigm for the treatment of antibiotic-resistant pseudomonas infections. In this respect, exotoxin A is one of the most potent virulence factors in P. aeruginosa. The present study was carried out to identify a novel human scFv antibody against the P. aeruginosa exotoxin A domain I (ExoA-DI) from a human scFv phage library. Methods The recombinant ExoA-DI of P. aeruginosa was expressed in E. coli, purified by Ni-NTA column, and used for screening of human antibody phage library. A novel screening procedure was conducted to prevent the elimination of rare specific clones. The phage clone with high reactivity was evaluated by ELISA and western blot. Results Based on the results of polyclonal phage ELISA, the fifth round of biopanning leads to the isolation of several ExoA-DI reactive clones. One positive clone with high affinity was selected by monoclonal phage ELISA and used for antibody expression. The purified scFv showed high reactivity with the recombinant domain I and full-length native exotoxin A. Conclusions The purified anti-exotoxin A scFv displayed high specificity against exotoxin A. The human scFv identified in this study could be the groundwork for developing a novel therapeutic agent to control P. aeruginosa infections.

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A Single-Domain Antibody-Based Anti-PSMA Recombinant Immunotoxin Exhibits Specificity and Efficacy for Prostate Cancer Therapy

International Journal of Molecular Sciences ◽

10.3390/ijms22115501 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5501

Author(s):

Yutong Xing ◽

Keyuan Xu ◽

Shixiong Li ◽

Li Cao ◽

Yue Nan ◽

...

Keyword(s):

Prostate Cancer ◽

Animal Studies ◽

Single Domain ◽

Soluble Form ◽

Therapeutic Window ◽

Single Domain Antibody ◽

Pseudomonas Exotoxin A ◽

Simple Strategy ◽

Domain Antibody ◽

Recombinant Immunotoxin

Prostate cancer (PCa) is the second most common cancer in men, causing more than 300,000 deaths every year worldwide. Due to their superior cell-killing ability and the relative simplicity of their preparation, immunotoxin molecules have great potential in the clinical treatment of cancer, and several such molecules have been approved for clinical application. In this study, we adopted a relatively simple strategy based on a single-domain antibody (sdAb) and an improved Pseudomonas exotoxin A (PE) toxin (PE24X7) to prepare a safer immunotoxin against prostate-specific membrane antigen (PSMA) for PCa treatment. The designed anti-PSMA immunotoxin, JVM-PE24X7, was conveniently prepared in its soluble form in an Escherichia coli (E. coli) system, avoiding the complex renaturation process needed for immunotoxin preparation by the conventional strategy. The product was very stable and showed a very strong ability to bind the PSMA receptor. Cytotoxicity assays showed that this molecule at a very low concentration could kill PSMA-positive PCa cells, with an EC50 value (concentration at which the cell viability decreased by 50%) of 15.3 pM against PSMA-positive LNCaP cells. Moreover, this molecule showed very good killing selectivity between PSMA-positive and PSMA-negative cells, with a selection ratio of more than 300-fold. Animal studies showed that this molecule at a very low dosage (5 × 0.5 mg/kg once every three days) completely inhibited the growth of PCa tumors, and the maximum tolerable dose (MTD) was more than 15 mg/kg, indicating its very potent tumor-treatment ability and a wide therapeutic window. Use of the new PE toxin, PE24X7, as the effector moiety significantly reduced off-target toxicity and improved the therapeutic window of the immunotoxin. The above results demonstrate that the designed anti-PSMA immunotoxin, JVM-PE24X7, has good application value for the treatment of PCa.

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Phage-Display Based Discovery and Characterization of Peptide Ligands against WDR5

Molecules ◽

10.3390/molecules26051225 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1225

Author(s):

Jiawen Cao ◽

Tiantian Fan ◽

Yanlian Li ◽

Zhiyan Du ◽

Lin Chen ◽

...

Keyword(s):

Phage Display ◽

Cyclic Peptide ◽

Protein Complexes ◽

Peptide Ligands ◽

Phage Library ◽

Cancer Drug ◽

Protein Protein Interaction ◽

Phage Display Technique ◽

Peptide Mimic ◽

Human Proteins

WD40 is a ubiquitous domain presented in at least 361 human proteins and acts as scaffold to form protein complexes. Among them, WDR5 protein is an important mediator in several protein complexes to exert its functions in histone modification and chromatin remodeling. Therefore, it was considered as a promising epigenetic target involving in anti-cancer drug development. In view of the protein–protein interaction nature of WDR5, we initialized a campaign to discover new peptide-mimic inhibitors of WDR5. In current study, we utilized the phage display technique and screened with a disulfide-based cyclic peptide phage library. Five rounds of biopanning were performed and isolated clones were sequenced. By analyzing the sequences, total five peptides were synthesized for binding assay. The four peptides are shown to have the moderate binding affinity. Finally, the detailed binding interactions were revealed by solving a WDR5-peptide cocrystal structure.

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