Latest Articles
Research Article | Molecular Biology and PhysiologyEfficient Expression of HIV in Immunocompetent Mouse Brain Reveals a Novel Nonneurotoxic Viral Function in Hippocampal Synaptodendritic Injury and Memory ImpairmentHIV neuropathogenesis has been attributed in large measure to neurotoxicity of viral proteins and inflammatory factors produced by infected monocytic cells in the brain. We show here that HIV expression in mouse brain causes lasting memory impairment by a mechanism involving injury to hippocampal synaptodendritic arbors and neuronal function but not overt neuronal loss in the region. Our results mirror the observation of minimal...
Research Article | Host-Microbe BiologyToxoplasma gondii Parasitophorous Vacuole Membrane-Associated Dense Granule Proteins Orchestrate Chronic Infection and GRA12 Underpins Resistance to Host Gamma InterferonToxoplasma gondii cysts reactivate during immune deficiency and cause fatal encephalitis. Parasite molecules that coordinate the development of acute and chronic infection are poorly characterized. Here, we show that many intravacuolar network membrane and parasitophorous vacuole membrane-associated dense granule (GRA) proteins orchestrate the development of chronic...
Research Article | Clinical Science and EpidemiologyPopulation Structure, Molecular Epidemiology, and β-Lactamase Diversity among Stenotrophomonas maltophilia Isolates in the United StatesMultiple antibiotic resistance mechanisms, including two β-lactamases, L1, a metallo-β-lactamase, and L2, a class A cephalosporinase, make S. maltophilia naturally multidrug resistant. Thus, infections caused by S. maltophilia pose a big therapeutic challenge. Our study aims to understand the...
Research Article | Molecular Biology and PhysiologyCrosstalk of Cellulose and Mannan Perception Pathways Leads to Inhibition of Cellulase Production in Several Filamentous FungiIn fungi, the production of enzymes for polysaccharide degradation is controlled by complex signaling networks. Previously, these networks were studied in response to simple sugars or single polysaccharides. Here, we tackled for the first time the molecular interplay between two seemingly unrelated perception pathways: those for cellulose and the hemicellulose (gluco)mannan. We identified a so far unknown competitive inhibition between...
Commentary | Molecular Biology and PhysiologyEmerging Roles for NlpE as a Sensor for Lipoprotein Maturation and Transport to the Outer Membrane in Escherichia coliOuter membrane biogenesis is a complex process for Gram-negative bacteria as the components are synthesized in the cytoplasm or at the inner membrane and then transported to the outer membrane. Stress pathways monitor and respond to problems encountered in assembling the outer membrane. The two-component system CpxAR was recently reported to be a stress pathway for transport of lipoproteins to the outer membrane, but it was unclear how...
Research Article | Host-Microbe BiologyThe Human Cytomegalovirus Chemokine vCXCL-1 Modulates Normal Dissemination Kinetics of Murine Cytomegalovirus In VivoAn adequate in vivo analysis of HCMV’s viral chemokine vCXCL-1 has been lacking. Here we generate recombinant MCMVs expressing vCXCL-1 to study vCXCL-1 function in vivo using MCMV as a surrogate. We demonstrate that vCXCL-1 increases MCMV dissemination kinetics for both primary and secondary dissemination. Additionally, we provide evidence, that the murine neutrophil is largely a bystander in the mouse’s response to...
Research Article | Clinical Science and EpidemiologyGenomic Characterization of the Emerging Pathogen Streptococcus pseudopneumoniaeS. pseudopneumoniae is an overlooked pathogen emerging as the causative agent of lower-respiratory-tract infections and associated with chronic obstructive pulmonary disease (COPD) and exacerbation of COPD. However, much remains unknown on its clinical importance and epidemiology, mainly due to the lack of specific markers to distinguish it from S. pneumoniae...
Research Article | Molecular Biology and PhysiologyIdentification of Extracellular DNA-Binding Proteins in the Biofilm MatrixMany bacteria are capable of forming biofilms encased in a matrix of self-produced extracellular polymeric substances (EPS) that protects them from chemotherapies and the host defenses. As a result of these inherent resistance mechanisms, bacterial biofilms are extremely difficult to eradicate and are associated with chronic wounds, orthopedic and surgical wound infections, and invasive infections, such as infective endocarditis and...
Research Article | Molecular Biology and PhysiologyDNA-Membrane Anchor Facilitates Efficient Chromosome Translocation at a Distance in Bacillus subtilisTo properly segregate their chromosomes, organisms tightly regulate the organization and dynamics of their DNA. Aspects of the process by which DNA is translocated during sporulation are not yet fully understood, such as what factors indirectly influence the activity of the motor protein SpoIIIE. In this work, we have shown that a DNA-membrane tether mediated by RacA contributes to the activity of SpoIIIE. Loss of RacA nearly doubles...
Research Article | Applied and Environmental ScienceSulfur-Oxidizing Symbionts without Canonical Genes for Autotrophic CO2 FixationMany animals and protists depend on symbiotic sulfur-oxidizing bacteria as their main food source. These bacteria use energy from oxidizing inorganic sulfur compounds to make biomass autotrophically from CO2, serving as primary producers for their hosts. Here we describe a clade of nonautotrophic sulfur-oxidizing symbionts, “Candidatus Kentron,” associated with marine ciliates. They lack genes for known autotrophic...