Difference between bacterial endotoxin and exotoxin

Protein in natureLipopolysaccharides in nature
Secreted both by Gram-positive and negative bacteria; diffuse into the surrounding mediumPart of Gram-negative bacterial cell wall
Actively secreted by the bacteriaReleased by cell lysis, Not by secretion
Heat labile, destroyed at 60°CHighly stable
Mostly enzyme-like actionMode of action – Induces ↑IL-1 and TNF
Specific action on particular issuesNonspecific (fever, shock, etc.)
Specific affinity for tissuesNo specific affinity for tissues
More potent, even smaller doses fatalOnly large doses are fatal
Highly antigenicPoorly antigenic
Neutralized by specific antibodiesNeutralization by antibodies is ineffective
Toxoid forms are used as a vaccine, e.g. tetanus toxoidNo effective vaccine is available using endotoxin