PAMPS

Lipopolysaccharide (LPS): Most gram-negatives. the dominant PAMP in intra-abdominal sepsis. The lipid A component of LPS binds LBP → CD14 → TLR4/MD-2 complex. This is the most potent trigger of the sepsis cascade and why gram-negative sepsis tends to be more fulminant.

Capsular Polysaccharide (CPS): B. fragilis produces a complex capsule (including PSA and PSB) that is crucial for abscess formation. This capsule is zwitterionic, meaning it contains both positive and negative charges, which allows it to interact with the host immune system to induce T cell-dependent abscess formation.

Note the existence of DAMPs as well: DAMPs — from the host tissue damage: This is where intra-abdominal sepsis is particularly nasty, because you have surgical trauma + ischaemia + peritoneal contamination all generating DAMPs simultaneously: (org-roam-db-location)