Spotlight
Molecular Pathogenesis
Molecular PathogenesisStaphylococcus aureus Isolated from Skin from Atopic-Dermatitis Patients Produces Staphylococcal Enterotoxin Y, Which Predominantly Induces T-Cell Receptor Vα-Specific Expansion of T CellsWhile investigating the virulence traits of Staphylococcus aureus adhering to the skin of atopic-dermatitis (AD) patients, we identified a novel open reading frame (ORF) with structural similarity to a superantigen from genome sequence data of an isolate from AD skin. Concurrently, the same ORF was identified in a bovine isolate of...
Molecular PathogenesisBacterial Energetic Requirements for Helicobacter pylori Cag Type IV Secretion System-Dependent Alterations in Gastric Epithelial CellsHelicobacter pylori colonizes the stomach in about half of the world’s population. H. pylori strains containing the cag pathogenicity island (cag PAI) are associated with a higher risk of gastric adenocarcinoma or peptic ulcer disease than cag PAI-negative strains. The...
Cellular Microbiology: Pathogen-Host Cell Molecular Interactions
Cellular Microbiology: Pathogen-Host Cell Molecular InteractionsPlasmodium falciparum Clag9-Associated PfRhopH Complex Is Involved in Merozoite Binding to Human ErythrocytesCytoadherence-linked asexual gene 9 (Clag9), a conserved Plasmodium protein expressed during the asexual blood stages, is involved in the cytoadherence of infected red blood cells (RBCs) to the endothelial lining of blood vessels. Here, we show that Plasmodium falciparum Clag9 (PfClag9) is a component of the PfClag9-RhopH complex that is involved in merozoite...
Cellular Microbiology: Pathogen-Host Cell Molecular InteractionsThe Host GTPase Arf1 and Its Effectors AP1 and PICK1 Stimulate Actin Polymerization and Exocytosis To Promote Entry of Listeria monocytogenesListeria monocytogenes is a foodborne bacterium that causes gastroenteritis, meningitis, or abortion. Listeria induces its internalization (entry) into some human cells through interaction of the bacterial surface protein InlB with its host receptor, the Met tyrosine kinase. InlB and Met promote entry through stimulation of localized actin polymerization and...
Cellular Microbiology: Pathogen-Host Cell Molecular InteractionsThe Nonmevalonate Pathway of Isoprenoid Biosynthesis Supports Anaerobic Growth of Listeria monocytogenesIsoprenoids are an essential and diverse class of molecules, present in all forms of life, that are synthesized from an essential common precursor derived from either the mevalonate pathway or the nonmevalonate pathway. Most bacteria have one pathway or the other, but the Gram-positive, facultative intracellular pathogen Listeria monocytogenes is unusual because it...
Cellular Microbiology: Pathogen-Host Cell Molecular Interactions | SpotlightBrucella abortus Depends on l-Serine Biosynthesis for Intracellular Proliferationl-Serine is a nonessential amino acid and a key intermediate in several relevant metabolic pathways. In bacteria, the major source of l-serine is the phosphorylated pathway, which comprises three enzymes: d-3-phosphoglycerate dehydrogenase (PGDH; SerA), phosphoserine amino transferase (PSAT; SerC), and l-phosphoserine phosphatase (PSP; SerB...
Bacterial Infections
Bacterial InfectionsThe Impacts of msaABCR on sarA-Associated Phenotypes Are Different in Divergent Clinical Isolates of Staphylococcus aureusThe staphylococcal accessory regulator (sarA) plays an important role in Staphylococcus aureus infections, including osteomyelitis, and the msaABCR operon has been implicated as an important factor in modulating expression of sarA. Thus, we investigated the contribution of msaABCR to sarA-associated phenotypes in the...
Bacterial InfectionsBypassing Phase Variation of Lipooligosaccharide (LOS): Using Heptose 1 Glycan Mutants To Establish Widespread Efficacy of Gonococcal Anti-LOS Monoclonal Antibody 2C7The sialylatable lacto-N-neotetraose (LNnT; Gal-GlcNAc-Gal-Glc) moiety from heptose I (HepI) of the lipooligosaccharide (LOS) of Neisseria gonorrhoeae undergoes positive selection during human infection. Lactose (Gal-Glc) from HepII, although phase variable, is commonly expressed in humans; loss of HepII lactose compromises gonococcal fitness in mice.
...
Host Response and Inflammation
Host Response and InflammationAspergillus fumigatus Cell Wall Promotes Apical Airway Epithelial Recruitment of Human NeutrophilsAspergillus fumigatus is a ubiquitous fungal pathogen capable of causing multiple pulmonary diseases, including invasive aspergillosis, chronic necrotizing aspergillosis, fungal colonization, and allergic bronchopulmonary aspergillosis. Intact mucociliary barrier function and early airway neutrophil responses are critical for clearing fungal conidia from the host...
Host Response and InflammationZBTB7B (ThPOK) Is Required for Pathogenesis of Cerebral Malaria and Protection against Pulmonary TuberculosisWe used a genome-wide screen in N-ethyl-N-nitrosourea (ENU)-mutagenized mice to identify genes in which recessive loss-of-function mutations protect against pathological neuroinflammation. We identified an R367Q mutation in the ZBTB7B (ThPOK) protein in which homozygosity causes protection against experimental cerebral malaria (ECM) caused by infection with...
Fungal and Parasitic Infections
Fungal and Parasitic InfectionsAlteration of Fermentative Metabolism Enhances Mucor circinelloides VirulenceThe fungus Mucor circinelloides undergoes yeast-mold dimorphism, a developmental process associated with its capability as a human opportunistic pathogen. Dimorphism is strongly influenced by carbon metabolism, and hence the type of metabolism likely affects fungus virulence. We investigated the role of ethanol metabolism in M. circinelloides virulence.
...
Fungal and Parasitic Infections | SpotlightCombination Immunotherapy with Passive Antibody and Sulfasalazine Accelerates Fungal Clearance and Promotes the Resolution of Pneumocystis-Associated ImmunopathogenesisThe pulmonary immune response protects healthy individuals against Pneumocystis pneumonia (PcP). However, the immune response also drives immunopathogenesis in patients who develop severe PcP, and it is generally accepted that optimal treatment requires combination strategies that promote fungal killing and also provide effective immunomodulation. The anti-inflammatory drug sulfasalazine programs macrophages for enhanced ...
Microbial Immunity and Vaccines
Microbial Immunity and VaccinesPreclinical Development and Assessment of Viral Vectors Expressing a Fusion Antigen of Plasmodium falciparum LSA1 and LSAP2 for Efficacy against Liver-Stage MalariaDespite promising progress in malaria vaccine development in recent years, an efficacious subunit vaccine against Plasmodium falciparum remains to be licensed and deployed. Cell-mediated protection from liver-stage malaria relies on a sufficient number of antigen-specific T cells reaching the liver during the time that parasites are present. A single vaccine...
Microbial Immunity and VaccinesInterferon Gamma Reprograms Host Mitochondrial Metabolism through Inhibition of Complex II To Control Intracellular Bacterial ReplicationThe mechanisms by which interferon gamma (IFN-γ) controls the replication of cytosolic pathogens independent of responses, such as the generation of reactive oxygen species/reactive nitrogen species (ROS/RNS), have not been fully elucidated. In the current study, we developed a model using Francisella tularensis, the causative agent of tularemia, in which pathways...
Microbial Immunity and VaccinesDendritic Cells Targeting Lactobacillus plantarum Strain NC8 with a Surface-Displayed Single-Chain Variable Fragment of CD11c Induce an Antigen-Specific Protective Cellular Immune ResponseInfluenza A virus (H1N1) is an acute, highly contagious respiratory virus. The use of lactic acid bacteria (LAB) to deliver mucosal vaccines against influenza virus infection is a research hot spot. In this study, two recombinant Lactobacillus plantarum strains expressing hemagglutinin (HA) alone or coexpressing aCD11c-HA to target HA protein to dendritic cells (DCs)...
Masthead
NEW! ASM Open Data Policy
Current Issue
About IAI
Infection and Immunity® (IAI) reports key discoveries that help microbiologists, immunologists, epidemiologists, pathologists, and clinicians to gain new insights into the underlying mechanisms of host-pathogen interactions and develop novel strategies to prevent or treat infectious diseases.
Commentary
The inflammatory response to the fungus Pneumocystis jirovecii plays a central role in the respiratory failure associated with Pneumocystis pneumonia. To help ameliorate the inflammatory response, corticosteroids are used as an adjuvant to standard antimicrobial therapy. Corticosteroids, however, can have a wide range of effects (including deleterious effects...