Anthrax toxins: A paradigm of bacterial immune suppression.
Several species of microorganism have developed immune evasion and/or immunosuppression strategies. Bacillus anthracis secretes two toxins, edema toxin and lethal toxin, that enter the cytosol of almost every cell type, including the cells of the innate and adaptive immune systems, and subvert cell signaling. Edema toxin causes a consistent elevation of cyclic adenosine monophosphate, whereas lethal toxin cleaves most isoforms of mitogen-activated protein kinase kinases. In a concerted manner, these toxins alter major signaling pathways involved in the development of immune-cell effector functions, with the inhibition of bacterial clearance by phagocytes and of B. anthracis-specific responses. Thus, B. anthracis can invade the host, with ensuing massive bacteremia and toxemia. Here, we review the specific effects of B. anthracis on neutrophils, macrophages, dendritic cells, T- and B-lymphocytes.
Baldari
Cosima T
CT
Department of Evolutionary Biology, University of Siena, 53100, Siena, Italy.
Tonello
Fiorella
F
Paccani
Silvia Rossi
SR
Montecucco
Cesare
C
D000818:Animals; D000881:Anthrax / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology*; D001408:Bacillus anthracis / Q000276:immunology*; D001427:Bacterial Toxins / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology / Q000382:microbiology; D006801:Humans; D008214:Lymphocytes / Q000276:immunology / Q000382:microbiology; D020935:MAP Kinase Signaling System / Q000276:immunology; D008264:Macrophages / Q000276:immunology / Q000382:microbiology
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; C030325:anthrax toxin