Glycosylation-dependent opsonophagocytic activity of staphylococcal protein A antibodies

Significance All currently licensed antibodies against bacteria target exotoxins. For most pathogens, neutralization of toxin(s) is not sufficient to prevent bacterial replication. Antibodies against surface determinants represent better candidates to enhance opsonophagocytic killing, but the mechanisms of action of such antibodies have not been systematically studied. Staphylococcal protein A is a conserved surface protein of Staphylococcus aureus and a crucial virulence determinant that manipulates B-cell responses and blocks deposition of opsonin. Monoclonal antibodies directed against SpA represent potential therapeutic agents as well as a formidable tool to identify and optimize effector functions of antibodies that can promote bacterial clearance.