Host-Microbe Biology
Research Article | Host-Microbe BiologyEpistatic Interplay between Type IV Secretion Effectors Engages the Small GTPase Rab2 in the Brucella Intracellular CycleBacterial pathogens with an intracellular lifestyle modulate many host cellular processes to promote their infectious cycle. They do so by delivering effector proteins into host cells via dedicated secretion systems that target specific host functions. While the roles of many individual effectors are known, how their modes of action are coordinated is rarely understood. Here, we show that the zoonotic bacterium...
Research Article | Host-Microbe BiologyDivergent Evolution of Legionella RCC1 Repeat Effectors Defines the Range of Ran GTPase Cycle TargetsLegionella pneumophila is a ubiquitous environmental bacterium which, upon inhalation, causes a life-threatening pneumonia termed Legionnaires’ disease. The opportunistic pathogen grows in amoebae and macrophages by employing a “type IV” secretion system, which secretes more than 300 different “effector” proteins into the host cell, where they subvert pivotal...
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 BiologyMetagenomic Exploration of the Marine Sponge Mycale hentscheli Uncovers Multiple Polyketide-Producing Bacterial SymbiontsMycale hentscheli is a marine sponge that is rich in bioactive small molecules. Here, we use direct metagenomic sequencing to elucidate highly complete and contiguous genomes for the major symbiotic bacteria of this sponge. We identify complete biosynthetic pathways for the three potent cytotoxic polyketides which have previously been isolated from M. hentscheli. Remarkably, and in contrast to previous studies of...
Commentary | Host-Microbe BiologyTowards a Mechanism for Poly(I·C) Antiviral Priming in OystersViral diseases cause significant losses in aquaculture. Prophylactic measures, such as immune priming, are promising control strategies. Treatment of the Pacific oyster (Crassostrea gigas) with the double-stranded RNA analog poly(I·C) confers long-term protection against infection with ostreid herpesvirus 1, the causative agent of Pacific oyster mortality syndrome. In...
Research Article | Host-Microbe BiologyNucleic Acid-Sensing Toll-Like Receptors Play a Dominant Role in Innate Immune Recognition of PneumococciThe pneumococcus is a bacterium that frequently causes infections in the lungs, ears, sinus cavities, and meninges. During these infections, body defenses are triggered by tissue-resident cells that use specialized receptors, such as Toll-like receptors (TLRs), to sense the presence of bacteria. We show here that pneumococci are predominantly detected by TLRs that are located inside intracellular vacuoles, including endosomes, where...
Research Article | Host-Microbe BiologyMagnaporthe oryzae Auxiliary Activity Protein MoAa91 Functions as Chitin-Binding Protein To Induce Appressorium Formation on Artificial Inductive Surfaces and Suppress Plant ImmunityThe rice blast fungus Magnaporthe oryzae generates infection structure appressoria in response to surface cues largely due to functions of signaling molecules, including G-proteins, regulators of G-protein signaling (RGS), mitogen-activated protein (MAP) kinase pathways, cAMP signaling, and TOR signaling pathways....
Research Article | Host-Microbe BiologyBordetella Dermonecrotic Toxin Is a Neurotropic Virulence Factor That Uses CaV3.1 as the Cell Surface ReceptorBordetella pertussis, which causes pertussis, a contagious respiratory disease, produces three major protein toxins, pertussis toxin, adenylate cyclase toxin, and dermonecrotic toxin (DNT), for which molecular actions have been elucidated. The former two toxins are known to be involved in the emergence of some clinical symptoms and/or contribute to the establishment...
Research Article | Host-Microbe BiologyEstimating the Timing of Early Simian-Human Immunodeficiency Virus Infections: a Comparison between Poisson Fitter and BEASTThe inference of the time of infection is a critical parameter in testing the efficacy of clinical interventions in protecting against HIV-1 infection. For example, in clinical trials evaluating the efficacy of passively delivered antibodies (Abs) for preventing infections, accurate time of infection data are essential for discerning levels of the Abs required to confer protection, given the natural Ab decay rate in the human body. In...
Research Article | Host-Microbe BiologyGlycemic Variability in Diabetes Increases the Severity of InfluenzaEvery winter, people with diabetes are at increased risk of severe influenza. At present, the mechanisms that cause this increased susceptibility are unclear. Here, we show that the fluctuations in blood glucose levels common in people with diabetes are associated with severe influenza. These data suggest that glycemic stability could become a greater clinical priority for patients with diabetes during outbreaks of influenza.
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