Iron-regulated surface determinant protein B (IsdB) (IsdB)

Iron-regulated surface determinant protein B (IsdB) is a cell wall-anchored protein expressed by Staphylococcus aureus that plays a pivotal role in bacterial iron acquisition (UniProt: P0C0S1). It acts as a receptor for human hemoglobin, binding it via NEAT (NEAr Transporter) domains to extract heme, which is then transported into the bacterium to provide essential iron (PubMed: 17606617). Given that iron is crucial for S. aureus survival and virulence, IsdB has been extensively targeted in vaccine development (PubMed: 16428815). The most prominent candidate, the V710 vaccine, reached Phase II/III clinical trials but was terminated due to safety concerns and lack of efficacy (PubMed: 21930924). Specifically, the trial revealed an increased risk of death in patients who received the vaccine and subsequently developed S. aureus infections. Despite this, IsdB remains a target of interest for monoclonal antibody therapies designed to starve the pathogen of iron. Understanding the structural basis of IsdB-hemoglobin interactions continues to inform the design of next-generation anti-staphylococcal interventions.

Other names

Iron-regulated surface determinant BHemoglobin receptor IsdBHeme-binding protein IsdBIsdB protein

Active immunization to generate neutralizing antibodies that inhibit hemoglobin binding and heme extraction; Passive immunization using monoclonal antibodies to block iron uptake (PubMed: 21930924, 17606617).