Induction of Necrosis in Human Neutrophils by Shigella flexneri Requires Type III Secretion, IpaB and IpaC Invasins, and Actin Polymerization
نویسندگان
چکیده
منابع مشابه
Induction of necrosis in human neutrophils by Shigella flexneri requires type III secretion, IpaB and IpaC invasins, and actin polymerization.
Infection by Shigella flexneri is characterized by infiltration of neutrophils in the intestinal mucosa and by a strong inflammatory reaction. Although neutrophils are constitutively programmed to die by apoptosis, we show that isolated human neutrophils undergo necrosis 2 h after infection with virulent S. flexneri strain M90T but not with the virulence plasmid-cured strain BS176. This was dem...
متن کاملThe Tripartite Type III Secreton of Shigella flexneri Inserts Ipab and Ipac into Host Membranes
Bacterial type III secretion systems serve to translocate proteins into eukaryotic cells, requiring a secreton and a translocator for proteins to pass the bacterial and host membranes. We used the contact hemolytic activity of Shigella flexneri to investigate its putative translocator. Hemolysis was caused by formation of a 25-A pore within the red blood cell (RBC) membrane. Of the five protein...
متن کاملLiposomes recruit IpaC to the Shigella flexneri type III secretion apparatus needle as a final step in secretion induction.
Shigella flexneri contact with enterocytes induces a burst of protein secretion via its type III secretion apparatus (TTSA) as an initial step in cellular invasion. We have previously reported that IpaD is positioned at the TTSA needle tip (M. Espina et al., Infect. Immuno. 74:4391-4400, 2006). From this position, IpaD senses small molecules in the environment to control the presentation of Ipa...
متن کاملInduction of Actin Polymerization in Permeabilized Neutrophils
We have used streptolysin-0 (SO)-permeabilized neutrophils to investigate the signal transduction pathway through which chemoattractants induce actin polymerization. Chemoattractants stimulate phosphorylation of various proteins and lipids but whether these phosphorylations are required for actin polymerization is not known. Addition of guanosine 5’-3-0-(thio)triphosphate (GTPyS) to SO-permeabi...
متن کاملBile salts stimulate recruitment of IpaB to the Shigella flexneri surface, where it colocalizes with IpaD at the tip of the type III secretion needle.
Shigella flexneri uses its type III secretion apparatus (TTSA) to deliver invasins into human cells. This TTSA possesses an external needle with IpaD at its tip. We now show that deoxycholate promotes the stable recruitment of IpaB to the needle tip without inducing a rapid burst of type III secretion. The maintenance of IpaB at the needle tip requires a stable association of IpaD with the Shig...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Infection and Immunity
سال: 2000
ISSN: 0019-9567,1098-5522
DOI: 10.1128/iai.68.3.1289-1296.2000