Exploiting cell death pathways by an E-coli cytotoxin:: Autophagy as a double-edged sword for the host

Cytotoxic necrotizing factor I is a bacterial protein toxin from Escherichia coli that is able to activate the Rho GTPases and to hinder apoptosis and mitotic catastrophe. Upon exposure to toxin, cells undergo a complex framework of changes, including cytoskeleton remodeling and multi nucleation. These cells also show a high survival rate for long periods of time and improve both their macropinocytotic scavenging activities and microautophagy. Only at the very end, probably when feeding materials are exhausted, do these cells die by autophagy. Taking into account the complex role of bacterial protein toxins in the infectious processes, we indicate the CNF1 activity as a Janus-faced paradigm of those bacteria that hijack cell fate to their own benefit. This could somehow be linked to the hypothesized connection between certain bacterial toxins and cancer onset.