Autophagy is induced by the type III secretion system of Vibrio alginolyticus in several mammalian cell lines

2010 ◽  
Vol 193 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Zhe Zhao ◽  
Lvping Zhang ◽  
Chunhua Ren ◽  
Jingjing Zhao ◽  
Chang Chen ◽  
...  
Keyword(s):  
Cell Lines ◽  
Mammalian Cell ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Vibrio Alginolyticus ◽  
Type Iii ◽  
Mammalian Cell Lines

Heterogeneity of type III secretion system (T3SS)-1-independent entry mechanisms used by Salmonella Enteritidis to invade different cell types

Microbiology ◽  
2011 ◽  
Vol 157 (3) ◽  
pp. 839-847 ◽  
Author(s):  
Manon Rosselin ◽  
Nadia Abed ◽  
Isabelle Virlogeux-Payant ◽  
Elisabeth Bottreau ◽  
Pierre-Yves Sizaret ◽  
...  
Keyword(s):  
Cell Lines ◽  
Type Iii Secretion ◽  
Salmonella Enteritidis ◽  
Type Iii Secretion System ◽  
Cell Types ◽  
Secretion System ◽  
Phagocytic Cells ◽  
Type Iii ◽  
Invasion Mechanisms ◽  
Wide Range

Salmonella causes a wide range of diseases from acute gastroenteritis to systemic typhoid fever, depending on the host. To invade non-phagocytic cells, Salmonella has developed different mechanisms. The main invasion system requires a type III secretion system (T3SS) known as T3SS-1, which promotes a Trigger entry mechanism. However, other invasion factors have recently been described in Salmonella, including Rck and PagN, which were not expressed under our bacterial culture conditions. Based on these observations, we used adhesion and invasion assays to analyse the respective roles of Salmonella Enteritidis T3SS-1-dependent and -independent invasion processes at different times of infection. Diverse cell lines and cell types were tested, including endothelial, epithelial and fibroblast cells. We demonstrated that cell susceptibility to the T3SS-1-independent entry differs by a factor of nine between the most and the least permissive cell lines tested. In addition, using scanning electron and confocal microscopy, we showed that T3SS-1-independent entry into cells was characterized by a Trigger-like alteration, as for the T3SS-1-dependent entry, and also by Zipper-like cellular alteration. Our results demonstrate for what is believed to be the first time that Salmonella can induce Trigger-like entry independently of T3SS-1 and can induce Zipper-like entry independently of Rck. Overall, these data open new avenues for discovering new invasion mechanisms in Salmonella.

scholarly journals The type III secretion system of Vibrio alginolyticus induces rapid apoptosis, cell rounding and osmotic lysis of fish cells

Microbiology ◽  
2010 ◽  
Vol 156 (9) ◽  
pp. 2864-2872 ◽  
Author(s):  
Zhe Zhao ◽  
Chang Chen ◽  
Chao-Qun Hu ◽  
Chun-Hua Ren ◽  
Jing-Jing Zhao ◽  
...  
Keyword(s):  
Cell Death ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Infected Fish ◽  
Secretion System ◽  
Vibrio Alginolyticus ◽  
Marine Animals ◽  
Cell Rounding ◽  
Type Iii ◽  
Fish Cells

Vibrio alginolyticus is a Gram-negative bacterium and has been recognized as an opportunistic pathogen in humans as well as marine animals. However, the virulence mechanisms for this species of Vibrio have not been elucidated. This study characterized multiple mechanisms that induce cell death in fish cells upon infection with a V. alginolyticus strain, ZJO. The bacterium required its type III secretion system (T3SS) to cause rapid death of infected fish cells. Dying cells exhibited some features of apoptotic cells, such as membrane blebbing, nuclear condensation and DNA fragmentation. Further studies showed that caspase-3 was activated by the T3SS of the ZJO strain, confirming that infection with V. alginolyticus rapidly induces T3SS-dependent apoptosis in fish cells. Infection with the ZJO strain also led to membrane pore formation and release of cellular contents from infected fish cells, as evidenced by lactate dehydrogenase release and the uptake of a membrane-impermeable dye. Importantly, inhibition of apoptosis did not prevent ZJO-infected cells from releasing cellular contents and did not block cell rounding. Taken together, these data demonstrate that infection with V. alginolyticus may promote at least three different T3SS-dependent events, which lead to the death of fish cells. This study provides an important insight into the mechanism used by Vibrio species to cause host-cell death.

Type III secretion system 1 of Vibrio parahaemolyticus induces oncosis in both epithelial and monocytic cell lines

Microbiology ◽  
2009 ◽  
Vol 155 (3) ◽  
pp. 837-851 ◽  
Author(s):  
Xiaohui Zhou ◽  
Michael E. Konkel ◽  
Douglas R. Call
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Type Iii Secretion ◽  
Vibrio Parahaemolyticus ◽  
Active Form ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Monocytic Cell ◽  
Type Iii ◽  
System 1

The Vibrio parahaemolyticus type III secretion system 1 (T3SS1) induces cytotoxicity in mammalian epithelial cells. We characterized the cell death phenotype in both epithelial (HeLa) and monocytic (U937) cell lines following infection with V. parahaemolyticus. Using a combination of the wild-type strain and gene knockouts, we confirmed that V. parahaemolyticus strain NY-4 was able to induce cell death in both cell lines via a T3SS1-dependent mechanism. Bacterial contact, but not internalization, was required for T3SS1-induced cytotoxicity. The mechanism of cell death involves formation of a pore structure on the surface of infected HeLa and U937 cells, as demonstrated by cellular swelling, uptake of cell membrane-impermeable dye and protection of cytotoxicity by osmoprotectant (PEG3350). Western blot analysis showed that poly ADP ribose polymerase (PARP) was not cleaved and remained in its full-length active form. This result was evident for seven different V. parahaemolyticus strains. V. parahaemolyticus-induced cytotoxicity was not inhibited by addition of the pan-caspase inhibitor carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]-fluoromethylketone (Z-VAD-FMK) or the caspase-1 inhibitor N-acetyl-tyrosyl-valyl-alanyl-aspartyl-aldehyde (Ac-YVAD-CHO); thus, caspases were not involved in T3SS1-induced cytotoxicity. DNA fragmentation was not evident following infection and autophagic vacuoles were not observed after monodansylcadaverine staining. We conclude that T3SS1 of V. parahaemolyticus strain NY-4 induces a host cell death primarily via oncosis rather than apoptosis, pyroptosis or autophagy.

Type III Secretion System–Associated Toxins, Proteases, Serotypes, and Antibiotic Resistance ofPseudomonas aeruginosaIsolates Associated with Keratitis

2006 ◽  
Vol 31 (4) ◽  
pp. 297-306 ◽  
Author(s):  
Hua Zhu ◽  
Tim C.R. Conibear ◽  
Rani Bandara ◽  
Yulina Aliwarga ◽  
Fiona Stapleton ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Type Iii
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