Artículos de revistas
A pore-forming toxin enables Serratia a nonlytic egress from host cells
Fecha
2016-08Registro en:
Di Venanzio, Gisela Andrea; Lazzaro, Martina; Morales, Enrique Salvador; Krapf, Dario; Garcia Vescovi, Eleonora; A pore-forming toxin enables Serratia a nonlytic egress from host cells; Wiley Blackwell Publishing, Inc; Cellular Microbiology (print); 19; 2; 8-2016; 1-12
1462-5814
CONICET Digital
CONICET
Autor
Di Venanzio, Gisela Andrea
Lazzaro, Martina
Morales, Enrique Salvador
Krapf, Dario
Garcia Vescovi, Eleonora
Resumen
Several pathogens co-opt host intracellular compartments to survive and replicate, and they thereafter disperse progeny to prosper in a new niche. Little is known about strategies displayed by Serratia marcescens to defeat immune responses and disseminate afterwards. Upon invasion of nonphagocytic cells, Serratia multiplies within autophagosome-like vacuoles. These Serratia-containing vacuoles (SeCV) circumvent progression into acidic/degradative compartments, avoiding elimination. In this work, we show that ShlA pore-forming toxin (PFT) commands Serratia escape from invaded cells. While ShlA-dependent, Ca2 + local increase was shown in SeCVs tight proximity, intracellular Ca2 + sequestration prevented Serratia exit. Accordingly, a Ca2 + surge rescued a ShlA-deficient strain exit capacity, demonstrating that Ca2 + mobilization is essential for egress. As opposed to wild-type-SeCV, the mutant strain-vacuole was wrapped by actin filaments, showing that ShlA expression rearranges host actin. Moreover, alteration of actin polymerization hindered wild-type Serratia escape, while increased intracellular Ca2 + reorganized the mutant strain-SeCV actin distribution, restoring wild-type-SeCV phenotype. Our results demonstrate that, by ShlA expression, Serratia triggers a Ca2 + signal that reshapes cytoskeleton dynamics and ends up pushing the SeCV load out of the cell, in an exocytic-like process. These results disclose that PFTs can be engaged in allowing bacteria to exit without compromising host cell integrity.