Anthrax lethal and edema toxins in anthrax pathogenesis

• CMG2 is the physiologically-relevant receptor for anthrax toxins in vivo.
• Targeting of innate immunity by the toxins is essential for initiation of infection.
• Anthrax toxins directly induce lethality at the terminal stage of infection.
• The cardiovascular system and liver are major targets for anthrax toxins.

The pathophysiological effects resulting from many bacterial diseases are caused by exotoxins released by the bacteria. Bacillus anthracis, a spore-forming bacterium, is such a pathogen, causing anthrax through a combination of bacterial infection and toxemia. B. anthracis causes natural infection in humans and animals and has been a top bioterrorism concern since the 2001 anthrax attacks in the USA. The exotoxins secreted by B. anthracis use capillary morphogenesis protein 2 (CMG2) as the major toxin receptor and play essential roles in pathogenesis during the entire course of the disease. This review focuses on the activities of anthrax toxins and their roles in initial and late stages of anthrax infection.