Lipid A

                                                  

                                       Richard Pffeifer = Endotoxin In Gram Negative Bacteria 

 

In the late 1800s, Richard Pfeiffer, a student of Robert Koch, described a toxic substance released from Gram-negative bacteria. He called it “endotoxin”, distinguishing it from exotoxins.

 

 

 

Scientists discovered that endotoxin was part of the outer membrane of Gram-negative bacteria

It was identified as a complex molecule called lipopolysaccharide (LPS)

LPS was shown to have three components:

• O-antigen
• Core polysaccharide
• A lipid component (later identified as Lipid A) 

 

 

 

 

• In the 1960s, Otto Westphal and colleagues demonstrated that Lipid A is the biologically active (toxic) center of LPS   

 

 

 

 

In 1998, Bruce A. Beutler discovered that Lipid A signals through Toll-like receptor 4 (TLR4)  

Fever

Septic shock

Cytokine storm in Gram-negative infections

 

Bruce Beutler: 2011 Nobel Prize In Physiology/Medicine  

 

 

 

 

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