Legionella pneumophila
Research Article | Host-Microbe BiologyPersistent Legionnaires’ Disease and Associated Antibiotic Treatment Engender a Highly Disturbed Pulmonary Microbiome Enriched in Opportunistic MicroorganismsThe composition and dynamics of the lung microbiome during pneumonia are not known, although the lung microbiome might influence the severity and outcome of this infectious disease, similar to what was shown for the microbiome at other body sites. Here we report the findings of a comprehensive analysis of the lung microbiome composition of three patients with long-term pneumonia due to...
Research Article | Host-Microbe BiologyA MicroRNA Network Controls Legionella pneumophila Replication in Human Macrophages via LGALS8 and MX1Cases of Legionella pneumophila pneumonia occur worldwide, with potentially fatal outcome. When causing human disease, Legionella injects a plethora of virulence factors to reprogram macrophages to circumvent immune defense and create a replication niche. By analyzing Legionella-induced changes in miRNA expression and genomewide chromatin...
Research Article | Host-Microbe BiologyAnalysis of Dot/Icm Type IVB Secretion System Subassemblies by Cryoelectron Tomography Reveals Conformational Changes Induced by DotB BindingMany bacteria use type IV secretion systems (T4SSs) to translocate proteins and nucleic acids into target cells, which promotes DNA transfer and host infection. The Dot/Icm T4SS in Legionella pneumophila is a multiprotein nanomachine that is known to translocate over 300 different protein effectors into eukaryotic host cells. Here, advanced cryoelectron tomography and...
Research Article | Host-Microbe BiologyIRG1 and Inducible Nitric Oxide Synthase Act Redundantly with Other Interferon-Gamma-Induced Factors To Restrict Intracellular Replication of Legionella pneumophilaLegionella pneumophila is one example among many species of pathogenic bacteria that replicate within mammalian macrophages during infection. The immune signaling factor interferon gamma (IFN-γ) blocks L. pneumophila replication in macrophages and is an essential component of the immune response to...
Research Article | Host-Microbe BiologyInteraction of the Ankyrin H Core Effector of Legionella with the Host LARP7 Component of the 7SK snRNP ComplexFor intracellular pathogens to thrive in host cells, an environment that supports survival and replication needs to be established. L. pneumophila accomplishes this through the activity of the ∼330 effector proteins that are injected into host cells during infection. Effector functions range from hijacking host trafficking pathways to altering host cell machinery,...
- Research ArticleType II Secretion-Dependent Aminopeptidase LapA and Acyltransferase PlaC Are Redundant for Nutrient Acquisition during Legionella pneumophila Intracellular Infection of Amoebas
Transmission of L. pneumophila to humans is facilitated by its ability to grow in Acanthamoeba species. We previously documented that type II secretion (T2S) promotes L. pneumophila infection of A. castellanii....
- Editor's Pick Research ArticleHost Cell S Phase Restricts Legionella pneumophila Intracellular Replication by Destabilizing the Membrane-Bound Replication Compartment
Legionella pneumophila has the ability to replicate within human macrophages and amoebal hosts. Here, we report that the host cell cycle influences L. pneumophila intracellular replication. Our data demonstrate that the G1 and G2/M phases of the host cell cycle are permissive for bacterial replication, while S phase is toxic for the bacterium. L. pneumophila replicates poorly within host...
- Research ArticleType II Secretion Substrates of Legionella pneumophila Translocate Out of the Pathogen-Occupied Vacuole via a Semipermeable Membrane
Infection of macrophages and amoebae plays a central role in the pathogenesis of L. pneumophila, the agent of Legionnaires’ disease. We have previously demonstrated that the T2S system of L. pneumophila greatly contributes to intracellular infection. However, the location of T2S substrates within the infected host cell is unknown. This report presents the first evidence of a L. pneumophila T2S substrate in the...
- Research ArticleA Unique cis-Encoded Small Noncoding RNA Is Regulating Legionella pneumophila Hfq Expression in a Life Cycle-Dependent Manner
The abilities of L. pneumophila to replicate intracellularly and to cause disease depend on its capacity to adapt to different extra- and intracellular environmental conditions. Therefore, a timely and fine-tuned expression of virulence factors and adaptation traits is crucial. Yet, the regulatory circuits governing the life cycle of L. pneumophila from replicating to virulent bacteria are only partly uncovered. Here...