Naslov
Maintaining Integrity of the Legionella pneumophila-containing Phagosome by the Dot/Icm Type IV Secretion System.

Autori
Molmeret, Maelle ; Šantić, Marina ; Asare, Rexford ; Abu-Zant, Alaeddin ; Abu Kwaik, Yousef

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
6th International Conference on Legionella. Book / Cianciotto, Nick - Chicago (IL) : ASM, 2006, 31-32

Skup
6th International Conference on Legionella

Mjesto i datum
Chicago (IL), Sjedinjene Američke Države, 16.10.2005. - 20.10.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Legionella; Dot/Icm; Phagosomal integrity

Sažetak
Background: Type IV secretion systems are utilized by many intracellular pathogens such as Legionella, Coxiella, Brucella, and Bartonella to export effectors into the host cell to evade endocytic fusion and to remodel the host cell into a replicative niche. Numerous studies have shown that phagosomes harboring L. pneumophila mutants defective in the Dot/Icm type IV secretion system co-localize with endosomal and lysosomal markers. Methods: Using confocal and electron microscopy, we show, here, a veiy surprising finding that the dot/icm mutants are unable to maintain integrity of the phagosome and are located free in the cytoplasm within minutes of entry into mammalian and protozoan cells. Results: In contrast, an isogenic htrA mutant, formalin-killed L. pneumophila, and E. coli controls whose phagosomes acquire endosomal and lysosomal markers, show the presence of a limiting membrane surrounding the organism. Integrity of the dot/icm mutants-containing phagosomes is restored upon complementation by the respective wild type genes. Lysosomal contents are dispersed on the bacteria and throughout the phagosomes of E. coli and formalin-killed L. pneumophila. In contrast, the lysosomal contents are vesicle-associated within vicinity of the dot/icm mutants located in the cytoplasm, but are never dispersed on the mutants. Conclusions: Thus, contribution of the Dot/Icm system to integrity of the L. pneumophila phagosome is a novel function for type IV secretion systems

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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