Poly-N-acetyl-beta-1,6-glucosamine (PNAG)

Poly-N-acetyl-beta-1,6-glucosamine (PNAG) is a major cell-surface polysaccharide and a key component of the extracellular biofilm matrix in Staphylococcus epidermidis, Staphylococcus aureus, and various other bacterial, fungal, and protozoal pathogens (Cywes-Bentley et al., 2013, Science Translational Medicine). It is synthesized by the products of the icaADBC gene locus and plays a critical role in intercellular adhesion and protecting the microbial community from host immune defenses, such as phagocytosis and complement-mediated killing (Mack et al., 1996, Journal of Bacteriology). PNAG is often partially deacetylated, a modification essential for its role in biofilm stability and immune evasion. As a therapeutic target, PNAG is highly attractive due to its conservation across diverse species, leading to the development of monoclonal antibodies like F598 and vaccines like AV0328 (Skurnik et al., 2010, Journal of Clinical Investigation). These therapies aim to facilitate opsonophagocytic killing of the bacteria or degrade the biofilm structure to enhance the efficacy of co-administered antibiotics.

Other names

Polysaccharide intercellular adhesinPIAPoly-N-acetylglucosamineDeacetylated poly-N-acetylglucosaminedPNAGbeta-1,6-GlcNAc

Monoclonal antibodies (e.g., F598) bind to PNAG on the bacterial surface to promote opsonophagocytic killing (OPK) by host neutrophils and macrophages. Enzymatic agents like Dispersin B specifically hydrolyze the beta-1,6-glycosidic bonds of the PNAG polymer, leading to the dissolution of the biofilm matrix and increasing bacterial susceptibility to antibiotics and host immune clearance.