A natural human monoclonal antibody targeting Staphylococcus Protein A protects against Staphylococcus aureus bacteremia.

Autor: Avanish K Varshney, Galina A Kuzmicheva, Jian Lin, Kevin M Sunley, Rodney A Bowling, Tzu-Yu Kwan, Heather R Mays, Anu Rambhadran, Yanfeng Zhang, Rebecca L Martin, Michael C Cavalier, John Simard, Sushma Shivaswamy
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: PLoS ONE, Vol 13, Iss 1, p e0190537 (2018)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0190537
Popis: Staphylococcus aureus can cause devastating and life-threatening infections. With the increase in multidrug resistant strains, novel therapies are needed. Limited success with active and passive immunization strategies have been attributed to S. aureus immune evasion. Here, we report on a monoclonal antibody, 514G3, that circumvents a key S. aureus evasion mechanism by targeting the cell wall moiety Protein A (SpA). SpA tightly binds most subclasses of immunoglobulins via their Fc region, neutralizing effector function. The organism can thus shield itself with a protective coat of serum antibodies and render humoral immunity ineffective. The present antibody reactivity was derived from an individual with natural anti-SpA antibody titers. The monoclonal antibody is of an IgG3 subclass, which differs critically from other immunoglobulin subclasses since its Fc is not bound by SpA. Moreover, it targets a unique epitope on SpA that allows it to bind in the presence of serum antibodies. Consequently, the antibody opsonizes S. aureus and maintains effector function to enable natural immune mediated clearance. The data presented here provide evidence that 514G3 antibody is able to successfully rescue mice from S. aureus mediated bacteremia.
Databáze: Directory of Open Access Journals
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