Sepsis is an extreme inflammatory response to infection that occurs in the bloodstream and causes damage throughout the body. Glycosylation is known to play a role in immunity and inflammation, but the role of glycans in sepsis is not well-defined. Herein, we profiled the serum glycomes of experimental mouse sepsis models to identify changes induced by 4 different clinical bacterial pathogens (Gram-positive: Streptococcus pneumoniae and Staphylococcus aureus, Gram-negative: Escherichia coli and Salmonella Typhimurium) using our lectin microarray technology. We observed global shifts in the blood sera glycome that were conserved across all four species, regardless of whether they were Gram positive or negative. Bisecting GlcNAc was decreased upon sepsis and a strong increase in core 1/3 O-glycans was observed. Lectin blot analysis revealed a high molecular weight protein induced in sepsis by all four bacteria as the major cause of the core 1/3 O-glycan shift. Analysis of this band by mass spectrometry identified interalpha-trypsin inhibitor heavy chains (ITIHs) and fibronectin, both of which are associated with human sepsis. Shifts in the glycosylation of these proteins were observed. Overall, our work points toward a common mechanism for bacterially induced sepsis, marked by conserved changes in the glycome.
Keywords: core 1/3 O-glycans; fibronectin; interalpha-trypsin inhibitor heavy chains (ITIHs); lectin microarray; sepsis; serum glycomics.