The molecular ecology of legionellae

Fields, Barry S.

doi:10.1016/0966-842x(96)10041-x

Cited by 496 publications

(464 citation statements)

References 50 publications

Supporting

Mentioning

449

Contrasting

Unclassified

Order By: Relevance

“…Legionella-laden amoebae or amoebal vesicles and cysts harbouring bacteria might also be part of the inoculum that precipitates lung infection (Berk et al, 1998;Brieland et al, 1997). Amoebae belonging to the genera Acanthamoeba, Echinamoeba, Hartmannella, Naegleria, Vahlkampfia and Willaertia coexist with L. pneumophila in water habitats, and at least 20 species representing these genera support L. pneumophila intracellular growth (Anand et al, 1983;Barbaree et al, 1986;Buse & Ashbolt, 2011;Cianciotto & Fields, 1992;Declerck et al, 2007;Dey et al, 2009;Fields et al, 1989;Fields, 1996;Harada et al, 2010;Harf & Monteil, 1988;Henke & Seidel, 1986;Holden et al, 1984;Hsu et al, 2011;Michel et al, 1998;Miyamoto et al, 2003;Molmeret et al, 2001;Newsome et al, 1985;Rowbotham, 1980Rowbotham, , 1986Tyndall & Domingue, 1982;Wadowsky et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

The novel Legionella pneumophila type II secretion substrate NttC contributes to infection of amoebae Hartmannella vermiformis and Willaertia magna

2014

View full text Add to dashboard Cite

The type II protein secretion (T2S) system of Legionella pneumophila secretes over 25 proteins, including novel proteins that have no similarity to proteins of known function. T2S is also critical for the ability of L. pneumophila to grow within its natural amoebal hosts, including Acanthamoeba castellanii, Hartmannella vermiformis and Naegleria lovaniensis. Thus, T2S has an important role in the natural history of legionnaires' disease. Our previous work demonstrated that the novel T2S substrate NttA promotes intracellular infection of A. castellanii, whereas the secreted RNase SrnA, acyltransferase PlaC, and metalloprotease ProA all promote infection of H. vermiformis and N. lovaniensis. In this study, we determined that another novel T2S substrate that is specific to Legionella, designated NttC, is unique in being required for intracellular infection of H. vermiformis but not for infection of N. lovaniensis or A. castellanii. Expanding our repertoire of amoebal hosts, we determined that Willaertia magna is susceptible to infection by L. pneumophila strains 130b, Philadelphia-1 and Paris. Furthermore, T2S and, more specifically, NttA, NttC and PlaC were required for infection of W. magna. Taken together, these data demonstrate that the T2S system of L. pneumophila is critical for infection of at least four types of aquatic amoebae and that the importance of the individual T2S substrates varies in a host cell-specific fashion. Finally, it is now clear that novel T2S-dependent proteins that are specific to the genus Legionella are particularly important for L. pneumophila infection of key, environmental hosts.

show abstract

Section: Introductionmentioning

confidence: 99%

The novel Legionella pneumophila type II secretion substrate NttC contributes to infection of amoebae Hartmannella vermiformis and Willaertia magna

2014

View full text Add to dashboard Cite

show abstract

“…Legionella are able to parasitize at least 20 different species of amoeba, two species of ciliated protozoa, and one slime mold (Lau and Ashbolt 2009), but are associated most frequently with amoeba belonging to the genera Acanthamoeba, Hartmanella, and Naegleria (Fields 1996). Interestingly, not all Legionella will grow in the same amoebal host (Rowbotham 1986) and certain amoeba seem also to be resistant to Legionella infection (Atlan et al 2012).…”

mentioning

confidence: 99%

Genome Dynamics in Legionella: The Basis of Versatility and Adaptation to Intracellular Replication

Gómez-Valero

Buchrieser

2013

Cold Spring Harbor Perspectives in Medicine

View full text Add to dashboard Cite

“…Legionella pneumophila | ankyrin repeat proteins | gC1qR (p32) | type IV secretion | pyroptosis T he bacterial pathogen Legionella pneumophila replicates inside protozoan hosts in soil and freshwater ecosystems (1). A type IV secretion apparatus encoded by the defect in organelle trafficking (dot) and intracellular multiplication (icm) genes is an essential virulence determinant used by L. pneumophila to deliver bacterial effector proteins into the eukaryotic cell (2,3).…”

mentioning

confidence: 99%

Inhibition of pathogen-induced apoptosis by a Coxiella burnetii type IV effector protein

Lührmann

Nogueira

Carey

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

148

173

View full text Add to dashboard Cite

Coxiella burnetii and Legionella pneumophila are evolutionarily related pathogens with different intracellular infection strategies. C. burnetii persists within and is transmitted by mammalian hosts, whereas, L. pneumophila is found primarily in the environment associated with protozoan hosts. Although a type IV secretion system encoded by the defect in organelle trafficking ( dot ) and intracellular multiplication ( icm ) genes is a virulence determinant that remains highly conserved in both bacteria, the two pathogens encode a different array of effector proteins that are delivered into host cells by the Dot/Icm machinery. This difference suggests that adaptations to evolutionarily distinct hosts may be reflected in the effector protein repertoires displayed by these two pathogens. Here we provide evidence in support of this hypothesis. We show that a unique C. burnetii effector from the ankyrin repeat (Ank) family called AnkG interferes with the mammalian apoptosis pathway. AnkG was found to interact with the host protein gC1qR (p32). Either the addition of AnkG to the repertoire of L. pneumophila effector proteins or the silencing of p32 in mouse dendritic cells resulted in a gain of function that allowed intracellular replication of L. pneumophila in these normally restrictive mammalian host cells by preventing rapid pathogen-induced apoptosis. These data indicate that p32 regulates pathogen-induced apoptosis and that AnkG functions to block this pathway. Thus, emergence of an effector protein that interferes with a proapoptotic signaling pathway directed against intracellular bacteria correlates with adaptation of a pathogen to mammalian hosts.

show abstract

The molecular ecology of legionellae

Cited by 496 publications

References 50 publications

The novel Legionella pneumophila type II secretion substrate NttC contributes to infection of amoebae Hartmannella vermiformis and Willaertia magna

The novel Legionella pneumophila type II secretion substrate NttC contributes to infection of amoebae Hartmannella vermiformis and Willaertia magna

Genome Dynamics in Legionella: The Basis of Versatility and Adaptation to Intracellular Replication

Inhibition of pathogen-induced apoptosis by a Coxiella burnetii type IV effector protein

Contact Info

Product

Resources

About