Chemical genetic screening identifies critical pathways in anthrax lethal toxin-induced pathogenesis.
Anthrax lethal toxin (LT)-induced cell death via mitogen-activated protein kinase kinase (MAPKK) cleavage remains questionable. Here, a chemical genetics approach was used to investigate what pathways mediate LT-induced cell death. Several small molecules were found to protect macrophages from anthrax LT cytotoxicity and MAPKK from cleavage by lethal factor (LF), without inhibiting LF enzymatic activity or cellular proteasome activity. Interestingly, the compounds activated MAPK-signaling molecules, induced proinflammatory cytokine production, and inhibited LT-induced macrophage apoptosis in a concentration-dependent manner. We propose that induction of antiapoptotic responses by MAPK-dependent or -independent pathways and activation of host innate responses may protect macrophages from anthrax LT-induced cell death. Altering host responses through a chemical genetics approach can help identify critical cellular pathways involved in the pathogenesis of anthrax and can be exploited to further explore host-pathogen interactions.
Panchal
Rekha G
RG
Target Structure-Based Drug Discovery Group, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA. rekha.panchal@amedd.army.mil
Ruthel
Gordon
G
Brittingham
Katherine C
KC
Lane
Douglas
D
Kenny
Tara A
TA
Gussio
Rick
R
Lazo
John S
JS
Bavari
Sina
S
D000818:Animals; D000942:Antigens, Bacterial / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D001427:Bacterial Toxins / Q000633:toxicity*; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D005820:Genetic Testing / Q000379:methods; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D051379:Mice; D018613:Microscopy, Confocal; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors*; D009336:Necrosis; D020687:cdc25 Phosphatases / Q000037:antagonists & inhibitors
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D018797:Cell Cycle Proteins; D016207:Cytokines; C030325:anthrax toxin; D020929:Mitogen-Activated Protein Kinase Kinases; D020687:cdc25 Phosphatases