Related Experiment Video
Updated: Dec 24, 2025
Peptide Scanning-assisted Identification of a Monoclonal Antibody-recognized Linear B-cell Epitope
Published on: March 24, 2017
Determining the immunological characteristics of a novel human monoclonal antibody developed against staphylococcal
Yuanyuan Liu1, Zhen Song1,2, Shuang Ge1
1National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China.
Abstract:
Staphylococci are the main cause of nosocomial infections globally. The exotoxin staphylococcal enterotoxin B (SEB) produced by methicillin-resistant Staphylococcus aureus is a major cause of pathology after a staphylococcal infection. We previously isolated an anti-SEB human monoclonal antibody designated as M0313. Here we further characterize this antibody in vitro and in vivo. Immunoblotting analysis and ELISA results indicated that M0313 accurately recognized and bound to SEB. Its binding affinity to native SEB was measured at the low nM level. M0313 effectively inhibited SEB from inducing mouse splenic lymphocyte and human peripheral blood mononuclear cell proliferation and cytokine release in cell culture. M0313 also neutralized SEB toxicity in BALB/c female mice. Most importantly, M0313 promoted the survival of mice treated with SEB-expressing bacteria. In-vivo imaging revealed that M0313 treatment significantly reduced the replication of SEB-expressing bacteria in mice. The neutralization capacity of M0313 correlated with its ability to block SEB from binding to major histocompatibility complex II and T-cell receptor by binding to the SEB residues 85-102 and 90-92. Thus, the monoclonal antibody M0313 may be developed into a therapeutic agent.
Insights
A novel human monoclonal antibody, M0313, effectively neutralizes staphylococcal enterotoxin B (SEB), a key cause of infections from bacteria like MRSA. This antibody shows therapeutic potential by reducing bacterial replication and improving survival rates in mice.
Area of Science:
- Microbiology
- Immunology
- Pharmacology
Background:
- Staphylococci, particularly methicillin-resistant Staphylococcus aureus (MRSA), are a leading cause of global nosocomial infections.
- Staphylococcal enterotoxin B (SEB) is a critical exotoxin contributing to pathology during staphylococcal infections.
Purpose of the Study:
- To characterize the in vitro and in vivo efficacy of a previously isolated anti-SEB human monoclonal antibody, M0313.
- To evaluate M0313's potential as a therapeutic agent against SEB-mediated pathology.
Main Methods:
- Immunoblotting and ELISA to assess M0313 binding to SEB.
- Cell culture assays to evaluate M0313's inhibition of lymphocyte proliferation and cytokine release.
- In vivo studies in BALB/c mice to assess SEB neutralization and efficacy against SEB-expressing bacteria.
- In vivo imaging to monitor bacterial replication.
- Analysis of M0313's binding sites on SEB and its interaction with MHC II and TCR.
Main Results:
- M0313 demonstrated specific and high-affinity binding (low nM) to native SEB.
- M0313 effectively inhibited SEB-induced proliferation and cytokine release in mouse and human cells.
- M0313 neutralized SEB toxicity in vivo and improved survival in mice challenged with SEB-expressing bacteria.
- In vivo imaging confirmed reduced bacterial replication following M0313 treatment.
- M0313's mechanism involves blocking SEB interaction with MHC II and TCR at specific residues.
Conclusions:
- The human monoclonal antibody M0313 exhibits potent neutralizing activity against staphylococcal enterotoxin B.
- M0313 demonstrates significant therapeutic potential for treating infections caused by SEB-producing staphylococci.
- Further development of M0313 as a clinical therapeutic agent is warranted.
More Related Videos
13:14Generation of Discriminative Human Monoclonal Antibodies from Rare Antigen-specific B Cells Circulating in Blood
Published on: February 6, 2018
09:07Single-cell Screening Method for the Selection and Recovery of Antibodies with Desired Specificities from Enriched Human Memory B Cell Populations
Published on: August 22, 2019
Related Concept Videos
01:31Hybridoma Technology
Hybridoma Selection
Commonly used fusion techniques — electroporation,...
01:26Antibody Actions
Neutralization
Antibodies can bind to pathogens, preventing them from infecting host cells. This process...
01:20Special Features of Adaptive Immunity
The primary cell types involved in adaptive immunity are T cells and B cells. Each type has a unique role in defending the body against pathogens. T cells are responsible for cell-mediated immunity. They identify and eliminate infected cells directly,...
01:10Antibody Structure
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
01:24B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
01:36Humoral Immune Responses