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Updated: Jul 11, 2025
Detection of SARS-CoV-2 Neutralizing Antibodies using High-Throughput Fluorescent Imaging of Pseudovirus Infection
Published on: June 5, 2021
Discovery of highly neutralizing human antibodies targeting Pseudomonas aeruginosa
Alexander Simonis1, Christoph Kreer2, Alexandra Albus3
1Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; German Center for Infection Research (DZIF), partner site Bonn-Cologne, 50937 Cologne, Germany.
Abstract:
Drug-resistant Pseudomonas aeruginosa (PA) poses an emerging threat to human health with urgent need for alternative therapeutic approaches. Here, we deciphered the B cell and antibody response to the virulence-associated type III secretion system (T3SS) in a cohort of patients chronically infected with PA. Single-cell analytics revealed a diverse B cell receptor repertoire directed against the T3SS needle-tip protein PcrV, enabling the production of monoclonal antibodies (mAbs) abrogating T3SS-mediated cytotoxicity. Mechanistic studies involving cryoelectron microscopy identified a surface-exposed C-terminal PcrV epitope as the target of highly neutralizing mAbs with broad activity against drug-resistant PA isolates. These anti-PcrV mAbs were as effective as treatment with conventional antibiotics in vivo. Our study reveals that chronically infected patients represent a source of neutralizing antibodies, which can be exploited as therapeutics against PA.
Insights
Drug-resistant Pseudomonas aeruginosa infections can be treated with new antibodies. These neutralizing antibodies, found in infected patients, target the PcrV protein and are effective against dangerous bacterial strains.
Area of Science:
- Immunology
- Microbiology
- Structural Biology
Background:
- Pseudomonas aeruginosa (PA) is a significant cause of drug-resistant infections.
- The type III secretion system (T3SS) is a key virulence factor in PA.
- Alternative therapies are urgently needed to combat PA infections.
Purpose of the Study:
- To investigate the B cell and antibody response to PA's T3SS in chronically infected patients.
- To identify and characterize neutralizing monoclonal antibodies (mAbs) against T3SS components.
- To evaluate the therapeutic potential of these mAbs against drug-resistant PA.
Main Methods:
- Single-cell analytics to analyze B cell receptor repertoire.
- Monoclonal antibody production and characterization.
- Cryoelectron microscopy for epitope mapping.
- In vivo efficacy studies comparing mAbs and antibiotics.
Main Results:
- A diverse B cell repertoire targeting the T3SS needle-tip protein PcrV was identified.
- Monoclonal antibodies (mAbs) were generated that neutralize T3SS-mediated cytotoxicity.
- A specific C-terminal PcrV epitope was identified as the target of broadly neutralizing mAbs.
- Anti-PcrV mAbs demonstrated efficacy in vivo, comparable to conventional antibiotics.
Conclusions:
- Chronically PA-infected patients harbor a valuable source of neutralizing antibodies.
- Anti-PcrV mAbs represent a promising therapeutic strategy against drug-resistant PA.
- Targeting the T3SS via PcrV offers a viable approach for novel anti-PA therapies.
