Pathobiont-driven antibody sialylation through IL-10 undermines vaccination

Area of Science:

• Immunology
• Microbiology
• Vaccinology

Background:

• Staphylococcus aureus (S. aureus) infections are a significant health concern, often associated with vaccine ineffectiveness.
• The precise mechanisms by which S. aureus impairs protective antibody responses remain incompletely understood.

Purpose of the Study:

• To elucidate the role of interleukin-10 (IL-10) in abrogating protective antibody responses against S. aureus.
• To investigate the molecular pathways linking IL-10 to altered antibody function and vaccine efficacy.

Main Methods:

• Studies in mouse models to assess the impact of IL-10 on B cell responses and antibody production.
• Analysis of STAT3 signaling and ST3gal4 gene expression in B cells.
• Glycosylation analysis of antibodies targeting S. aureus antigens (IsdB, IsdA, MntC).
• Comparison of antibody sialylation in human samples from cystic fibrosis patients and healthy individuals.

Main Results:

• IL-10 is identified as the key mediator of suppressed antibody protection in mice.
• S. aureus-induced B10 cells release IL-10, which promotes B cell expression of sialyltransferase ST3gal4 via STAT3.
• This leads to increased α2,3sialylation of antibodies, diminishing their protective capacity against S. aureus.
• Human antibodies from individuals with high IL-10 levels (cystic fibrosis patients) show similar hypersialylation patterns.

Conclusions:

• A novel pathobiont-centric mechanism is revealed where IL-10 modulates antibody glycosylation.
• This IL-10-driven hypersialylation of antibodies results in the loss of vaccine efficacy against S. aureus.
• Findings highlight IL-10 as a critical target for improving staphylococcal vaccine strategies.