X-ray images have revealed how anthrax hijacks important cell machinery to enter and destroy human cells. Researchers from The Burnham Institute and the National Institute of Allergy and Infectious Diseases discovered the structure of an anthrax toxin bound with a cell receptor using data taken at SSRL. The clearer picture of how anthrax works brings researchers closer to the development of a therapy against anthrax infection as well as a new cancer therapeutic.

Bacillus anthracis makes three toxins that disrupt our immune systems. One, called protective antigen (PA), can bind to two types of receptors on the surface of human cells. PA hijacks the receptor called CMG2, forcing it to act as a molecular switch to send PA and the other anthrax toxins into the cell. Once inside, the toxin stops the cells from mounting an immune response to the bacteria, and ultimately kills the cell. The new information on how PA recognizes and tricks cell receptors is potent information for designing anti-anthrax drugs that derail the PA-CMG2 interaction. The other cell receptor that PA recognizes is found primarily on the surface of cells lining the blood vessels that supply nutrients to tumors. Killing these cells using an engineered toxin presents a possible new cancer treatment.

To learn more about this research see the full scientific highlight at:
http://www-ssrl.slac.stanford.edu/research/highlights_archive/anthrax3.html

Santelli E, Bankston LA, Leppla SH, Liddington RC "Crystal structure of a complex between anthrax toxin and its host cell receptor" Nature 430, 905-8 (2004)