Host-Pathogen Interactions:
The interactions between a host and a pathogen, usually resulting in disease.
JoVE Immunology and Infection
Infection of Zebrafish Embryos with Intracellular Bacterial Pathogens
1Department of Molecular Cell Biology, Institute of Biology, Leiden University, 2Department of Medical Microbiology and Infection Control, VU University Medical Center, 3Australian Regenerative Medicine Institute, Monash University
Transparent zebrafish embryos have proved useful model hosts to visualize and functionally study interactions between innate immune cells and intracellular bacterial pathogens, such as Salmonella typhimurium and Mycobacterium marinum. Micro-injection of bacteria and multi-color fluorescence imaging are essential techniques involved in the application of zebrafish embryo infection models.
JoVE Immunology and Infection
Non-invasive Imaging of Disseminated Candidiasis in Zebrafish Larvae
Department of Molecular and Biomedical Sciences, University of Maine
The rapid development, small size and transparency of zebrafish are tremendous advantages for the study of innate immune control of infection1-4. Here we demonstrate techniques for infecting zebrafish larvae using the fungal pathogen Candida albicans by microinjection, methodology recently used to implicate phagocyte NADPH oxidase activity in control of fungal dimorphism5.
JoVE Immunology and Infection
In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells
This protocol is a simple bacterial adhesion assay consisting in counting the numbers of bacterial colony forming units that are adhered onto cultured cells. The assay is robust, independent of the adhesin studied, and numerous variations are used in most laboratories working on bacterial pathogenesis.
JoVE Immunology and Infection
RNAi Screening for Host Factors Involved in Vaccinia Virus Infection using Drosophila Cells
Department of Microbiology, Penn Genome Frontiers Institute, University of Pennsylvania
Novel host factors involved in viral infection can be identified through cell-based genome-wide loss of function RNAi screening. A Drosophila cell culture model is particularly amenable to this approach due to the ease and efficiency of RNAi. Here we demonstrate this technique using vaccinia virus as an example.
JoVE General
Chronic Salmonella Infected Mouse Model
Department of Medicine, University of Rochester
Establish a chronic bacterial infected mouse model with persistent Salmonella typhimurium colonization in intestine for 27 weeks.
JoVE General
Microfluidic Co-culture of Epithelial Cells and Bacteria for Investigating Soluble Signal-mediated Interactions
1McFerrin Department of Chemical Engineering, Texas A&M University, 2Department of Biomedical Engineering, Texas A&M University
This protocol describes a microfluidic co-culture model for simultaneous and localized culture of epithelial cells and bacteria. This model can be used for investigating the role of different soluble molecular signals on pathogenesis as well as screen the effectiveness of putative probiotic bacterial strains.
JoVE Immunology and Infection
Use of the EpiAirway Model for Characterizing Long-term Host-pathogen Interactions
Division of Basic Medical Sciences, Mercer University School of Medicine
This method allows characterization of extended bacterial co-culture with EpiAirways, primary human respiratory epithelial tissue grown at the air-liquid interface, a biologically relevant in vitro model. The approach can be used with any microbe that is amenable to long-term co-culture.
JoVE General
Expression, Detergent Solubilization, and Purification of a Membrane Transporter, the MexB Multidrug Resistance Protein
Department of Biological Sciences, University of Illinois Chicago - UIC
In this protocol we demonstrate the expression, solubilization, and purification of a recombinantly expressed membrane protein, MexB, as a soluble protein detergent complex. MexB is a multidrug resistance membrane transporter from the opportunistic bacterial pathogen Pseudomonas aeruginosa.
JoVE Immunology and Infection
Saliva, Salivary Gland, and Hemolymph Collection from Ixodes scapularis Ticks
1Microbiology and Pathogenesis Activity, Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 2Tick-Borne Diseases Activity, Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention
The collection of infected tick hemolymph, salivary glands, and saliva is important to study how tick-borne pathogens cause disease. In this protocol we demonstrate how to collect hemolymph and salivary glands from feeding Ixodes scapularis nymphs. We also demonstrate saliva collection from female I. scapularis adults.
JoVE Immunology and Infection
Live-cell Video Microscopy of Fungal Pathogen Phagocytosis
1Division of Applied Medicine, University of Aberdeen, 2Aberdeen Fungal Group, University of Aberdeen
We describe methods for live-cell video microscopy of Candida albicans phagocytosis by macrophages. These methods enable stage-specific analysis of macrophage migration, recognition, engulfment and phagosome maturation and reveal novel aspects of phagocytosis.
JoVE Immunology and Infection
Dissecting Host-virus Interaction in Lytic Replication of a Model Herpesvirus
1Center for Autophagy Research, Department of Internal Medicine, UT Southwestern Medical Center, 2Department of Microbiology, UT Southwestern Medical Center
We describe a protocol to identify key roles of host signaling molecules in lytic replication of a model herpesvirus, gamma herpesvirus 68 (γHV68). Utilizing genetically modified mouse strains and embryonic fibroblasts for γHV68 lytic replication, the protocol permits both phenotypic characterization and molecular interrogation of virus-host interactions in viral lytic replication.
JoVE Immunology and Infection
Sample Preparation of Mycobacterium tuberculosis Extracts for Nuclear Magnetic Resonance Metabolomic Studies
1School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, 2Department of Chemistry, University of Nebraska-Lincoln
The metabolomic profile of Mycobacterium tuberculosis is determined after growth in broth cultures. Conditions can be varied to test the effects of nutritional supplements, oxidants, and anti-tuberculosis agents on the metabolic profile of this microorganism. Procedure for extract preparation is applicable for both 1D 1H and 2D 1H-13C NMR analyses.
JoVE Immunology and Infection
Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes
1St Vincent’s Institute, Department of Medicine, The University of Melbourne, 2Department of Microbiology and Immunology, The University of Melbourne
Listeria monocytogenes is a model organism for studying immune responses and genetic susceptibility to intracellular bacteria in mice. This method enables one to measure bacterial load and generate single-cell suspensions of the liver and spleen from mice for FACS analysis to determine changes in immune cells due to Listeria infection.
JoVE Immunology and Infection
A Functional Whole Blood Assay to Measure Viability of Mycobacteria, using Reporter-Gene Tagged BCG or M.Tb (BCG lux/M.Tb lux)
1Department of Paediatrics, Imperial College London, 2Centre for Health Sciences, Barts & The London School of Medicine and Dentistry
We describe an alternative approach to the enumeration of mycobacteria in vitro, which uses reporter-gene tagged mycobacteria instead of colony-forming units (CFU). “Survival” of organisms as well as host response-markers are measured simultaneously, providing a low-cost, versatile and functional system for studies of host/pathogen interactions in the context of tuberculosis.
JoVE General
Quantitative and Automated High-throughput Genome-wide RNAi Screens in C. elegans
Centre d’Immunologie de Marseille-Luminy, Université de la Méditerranée
We describe a protocol using C. elegans and RNAi feeding libraries that allows automated measurement of multiple parameters such as fluorescence, size and opacity of individual worms in a population. We give one example of a screen to identify genes involved in anti-fungal innate immunity in C. elegans.
JoVE Immunology and Infection
The Insect Galleria mellonella as a Powerful Infection Model to Investigate Bacterial Pathogenesis
Oral and intra haemocolic infection of larvae of the greater wax moth Galleria mellonella is described. This insect can be used to study virulence factors of entomopathogenic as well as mammalian opportunistic bacteria. Rearing of the insects, methods of infection and examples of in vivo analysis are described.
JoVE Immunology and Infection
Introducing Shear Stress in the Study of Bacterial Adhesion
Blood vessels as a target for infection, Paris center for cardiovascular research, INSERM U970
During the infection process, a key step is the adhesion of pathogens with host cells. In most instances this adhesion step occurs in the presence of mechanical stress generated by flowing liquid. We describe a technique that introduces shear stress as an important parameter in the study of bacterial adhesion.
JoVE Immunology and Infection
The Citrobacter rodentium Mouse Model: Studying Pathogen and Host Contributions to Infectious Colitis
Division of Gastroenterology, BC Children's Hospital
Citrobacter rodentium infection provides a valuable model to study enteric bacterial infections as well as host immune responses and colitis in mice. This protocol outlines the measurement of barrier integrity, pathogen load and histological damage allowing for the thorough characterization of pathogen and host contributions to murine infectious colitis.
JoVE Immunology and Infection
Use of an Optical Trap for Study of Host-Pathogen Interactions for Dynamic Live Cell Imaging
1Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, 2Department of Mechanical and Aerospace Engineering, The Ohio State University, 3Center for Computational and Integrative Biology, Massachusetts General Hospital, Harvard Medical School, 4Dept. of Chemical and Biomolecular Engineering, Vanderbilt University
A method is described to individually select, manipulate, and image live pathogens using an optical trap coupled to a spinning disk microscope. The optical trap provides spatial and temporal control of organisms and places them adjacent to host cells. Fluorescence microscopy captures dynamic intercellular interactions with minimal perturbation to cells.
JoVE Immunology and Infection
Derivation of Thymic Lymphoma T-cell Lines from Atm-/- and p53-/- Mice
Department of Biomedical Sciences, Cornell University
In this video we demonstrate a protocol to establish mouse thymic lymphoma cell lines. By following this protocol, we have successfully established several T-cell lines from Atm-/- and p53-/- mice with thymic lymphoma.
JoVE General
Culturing and Applications of Rotating Wall Vessel Bioreactor Derived 3D Epithelial Cell Models
Basic Medical Sciences, University of Arizona College of Medicine - Phoenix
A rotating cell culture system that allows epithelial cells to grow under physiological conditions resulting in 3-D cellular aggregate formation is described. The aggregates generated display in vivo-like characteristics not observed in conventional culture models and serve as a more accurate organotypic model system for a multitude of scientific investigations.
JoVE Immunology and Infection
Purification of Pathogen Vacuoles from Legionella-infected Phagocytes
Max von Pettenkofer-Institut, Ludwig-Maximilians-Universität
This article describes a method for the isolation and purification of intact Legionella-containing vacuoles (LCVs) from amoeba and macrophages. The two-step protocol comprises LCV enrichment by immuno-magnetic separation using an antibody against a bacterial LCV marker and further purification by density gradient centrifugation.
JoVE Bioengineering
Rotating Cell Culture Systems for Human Cell Culture: Human Trophoblast Cells as a Model
1Department of Microbiology and Immunology, Tulane University Medical School, 2Physician/Scientist Program, Tulane University Medical School, 3Department of Molecular and Cellular Biology, Baylor College of Medicine
Traditional, two dimensional cell culture techniques often result in altered characteristics with respect to differentiation markers, cytokines and growth factors. Three-dimensional cell culture in the rotating cell culture system (RCCS) reestablishes expression of many of these factors as shown here with an extravillous trophoblast cell line.
JoVE Immunology and Infection
Co-culture Models of Pseudomonas aeruginosa Biofilms Grown on Live Human Airway Cells
1Department of Physiology, Dartmouth College, 2Department of Biology, Indiana University Purdue University Indianapolis
This paper describes different methods of growing Pseudomonas aeruginosa biofilms on cultured human airway epithelial cells. These protocols can be adapted to study different aspects of biofilm formation, including visualization of the biofilm, staining of the biofilm, measuring the colony forming units (CFU) of the biofilm, and studying biofilm cytotoxicity.
JoVE General
A Technique to Simultaneously Visualize Virus-Specific CD8+ T Cells and Virus-Infected Cells In situ
1Department of Microbiology, Medical School, University of Minnesota, 2Department of Veterinary and Biomedical Sciences, University of Minnesota
A technique combining in situ tetramer staining and in situ hybridization (ISTH) enables visualization, mapping and analysis of the spatial proximity of virus-specific CD8+ T cells to their virus-infected targets, and determination of the quantitative relationships between these immune effectors and targets to infection outcomes.
JoVE Immunology and Infection
Rearing and Injection of Manduca sexta Larvae to Assess Bacterial Virulence
Department of Bacteriology, University of Wisconsin-Madison
The method described here utilizes direct injection of entomopathogenic bacteria into the hemocoel of Manduca sexta insect larvae. M. sexta is a commercially available and well-studied insect. Thus, this method represents a simple approach to analyzing host-bacterial interactions from the perspective of one or both partners.
JoVE Immunology and Infection
An Analytical Tool-box for Comprehensive Biochemical, Structural and Transcriptome Evaluation of Oral Biofilms Mediated by Mutans Streptococci
1Center for Oral Biology, University of Rochester Medical Center, 2State Key Laboratory of Oral Diseases, Sichuan University, 3Department of General Medicine, Glostrup Hospital, Glostrup, Denmark, 4Department of Microbiology and Immunology, University of Rochester Medical Center
Biofilms formed on tooth surfaces are highly complex and exposed to constant innate and exogenous environmental challenges, which modulate their architecture, physiology and transcriptome. We developed a toolbox to examine the composition, structural organization and gene expression of oral biofilms, which can be adapted to other areas of biofilm research.
JoVE Immunology and Infection
Using Eggs from Schistosoma mansoni as an In vivo Model of Helminth-induced Lung Inflammation
1Institute of Immunology, Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, 2Pathobiology, School of Veterinary Medicine, University of Pennsylvania
Schistosoma mansoni eggs are potent stimulators of the T helper type 2 (Th2) immune response, characteristic of parasite infection, asthma and allergic inflammation. This protocol utilizes S. mansoni egg injection to generate a CD4 Th2 cytokine-induced inflammatory response in the lung, characterized by lung granuloma formation around the egg, eosinophilia and macrophage alternative activation.
JoVE General
Visualizing Bacteria in Nematodes using Fluorescent Microscopy
Department of Bacteriology, University of Wisconsin-Madison
To study the mutualism between Xenorhabdus bacteria and Steinernema nematodes, methods were developed to monitor bacterial presence and location within nematodes. The experimental approach, which can be applied to other systems, entails engineering bacteria to express the green fluorescent protein and visualizing, using fluorescence microscopy bacteria within the transparent nematode.
JoVE Immunology and Infection
A Visual Assay to Monitor T6SS-mediated Bacterial Competition
We describe a qualitative assay to monitor bacterial competition mediated by the Pseudomonas aeruginosa type VI secretion system (T6SS). The assay relies on the survival/killing of Escherichia coli target cells carrying a lacZ-reporter. This technique is adjustable to assess the bactericidal/bacteriostasis activity of T6SS-proficient microorganisms.
JoVE Immunology and Infection
RNA Interference in Ticks
1Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 2(CSIC-UCLM-JCCM), Instituto de Investigación en Recursos Cinegéticos IREC
A method for RNA interference (RNAi) by injection of dsRNA into unfed ticks is described. RNAi is the most widely used gene-silencing technique in ticks where the use of other methods of genetic manipulation has been limited.
JoVE Immunology and Infection
Isolation and Characterization of Dendritic Cells and Macrophages from the Mouse Intestine
1Department of Pediatrics, Emory University, 2Department of Pathology & Laboratory Medicine, Emory University
Here, we detail a methodology for the rapid isolation of mouse intestinal dendritic cells (DCs) and macrophages. Phenotypic characterization of intestinal DCs and macrophages is performed using multi-color flow cytometric analysis while magnetic bead enrichment followed by cell sorting is used to yield highly pure populations for functional studies.
JoVE Immunology and Infection
Alphavirus Transducing System: Tools for Visualizing Infection in Mosquito Vectors
Microbiology, Immunology, and Pathology, Colorado State University
Methods for using alphavirus transducing systems to express fluorescent reporters in vitro and in adult mosquitoes are described. This technique may be adapted to express any protein of interest in lieu of or in addition to a reporter.
JoVE Immunology and Infection
A 96 Well Microtiter Plate-based Method for Monitoring Formation and Antifungal Susceptibility Testing of Candida albicans Biofilms
1Department of Biology, University of Texas San Antonio - UTSA, 2South Texas Center for Emerging Infectious Diseases, University of Texas San Antonio - UTSA
We describe a simple, rapid and robust method for the formation of Candida albicans biofilms using 96 well microtiter plates and its utility in antifungal susceptibility testing of cells within biofilms.
JoVE General
Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 2
Whitehead Institute for Biomedical Research, MIT - Massachusetts Institute of Technology
Protocol for Vaccinia infection of HeLa cells and analysis of host and viral gene expression. Part 2 of 3.
JoVE General
Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 3
Whitehead Institute for Biomedical Research, MIT - Massachusetts Institute of Technology
Protocol for Vaccinia infection of HeLa cells and analysis of host and viral gene expression. Part 3 describes the process of fluorescently labeling the amplified RNA from both host and viral samples by amino allyl coupling of dyes. Part 3 of 3.
JoVE Neuroscience
Brain Imaging Investigation of the Neural Correlates of Observing Virtual Social Interactions
1Department of Computing Science, University of Alberta, 2Department of Psychology, University of Illinois, 3Centre for Neuroscience, University of Alberta, 4Department of Psychology, University of Alberta, 5Department of Marketing, Business Economics, and Law, University of Alberta, 6Neuroscience Program, University of Illinois at Urbana-Champaign, 7Beckman Institute, University of Illinois at Urbana-Champaign
This article demonstrates an experimental design in which whole-body animated characters are used in conjunction with functional magnetic resonance imaging (fMRI) to investigate the neural correlates of observing virtual social interactions.
JoVE General
Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 1
Whitehead Institute for Biomedical Research, MIT - Massachusetts Institute of Technology
Protocol for Vaccinia infection of HeLa cells and analysis of host and viral gene expression. Part 1 of 3.
JoVE Clinical and Translational Medicine
Preparation and Pathogen Inactivation of Double Dose Buffy Coat Platelet Products using the INTERCEPT Blood System
Department of Laboratory Medicine, Section for Transfusion Medicine, Örebro University Hospital
This article describes the process used by Örebro University Hospital to produce double dose buffy coat platelet concentrates prepared from whole blood donations and treated with the INTERCEPT Blood System for pathogen inactivation. The in vitro quality of the final platelet units are evaluated over 7 days of storage.
JoVE Immunology and Infection
Tractable Mammalian Cell Infections with Protozoan-primed Bacteria
Department of Molecular Microbiology & Immunology, Oregon Health & Science University
This technique provides a method to harvest, normalize and quantify intracellular growth of bacterial pathogens that are pre-cultivated in natural protozoan host cells prior to infections of mammalian cells. This method can be modified to accommodate a wide variety of host cells for the priming stage as well as target cell types.
JoVE Immunology and Infection
Induction of Alloantigen-specific Anergy in Human Peripheral Blood Mononuclear Cells by Alloantigen Stimulation with Co-stimulatory Signal Blockade
1Medical Oncology, Dana Farber Cancer Institute, 2Department of Medicine, Brigham and Womens Hospital, 3Pediatric Oncology, Dana Farber Cancer Institute, 4Division of Hematology/Oncology, Children’s Hospital Boston
This paper describes a simple technique to induce alloantigen-specific anergy in human peripheral blood mononuclear cells. The technique can be applied clinically to generate non-alloreactive donor cells. Infusion of these cells could improve immune reconstitution and reduce toxicity after allogeneic hematopoietic stem cell transplantation.
JoVE Clinical and Translational Medicine
A Human Fallopian Tube Model for Investigation of C. trachomatis Infections
1Institute of Medical Microbiology and Hygiene, University of Lübeck, 2Institute of Anatomie, University of Lübeck, 3Department of Obstetrics and Gynecology, University Hospital of Schleswig-Holstein, University of Lübeck, 4Medical Clinic III, University Hospital of Schleswig-Holstein, University of Lübeck
We describe an ex vivo infection model for visualisation of direct interactions from bacterial pathogens with human fallopian tube cells. The whole organ tissue model was established to investigate C. trachomatis induced pathology to the female fallopian tube under "life-like" conditions.
JoVE General
Identification of Growth Inhibition Phenotypes Induced by Expression of Bacterial Type III Effectors in Yeast
Department of Plant Sciences, Tel Aviv University
In this video, we describe a procedure for the expression of bacterial type III effectors in yeast and the identification of effector-induced growth inhibition phenotypes. Such phenotypes can be subsequently exploited to elucidate effector functions and targets.
JoVE Editorial
September 2011: This Month in JoVE
Here are some highlights from the September 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE Bioengineering
A Toolkit to Enable Hydrocarbon Conversion in Aqueous Environments
1Department of Biotechnology, Delft University of Technology, 2Delft Center for Systems and Control, Delft University of Technology
A sustainable auto regulating bacterial system for the remediation of oil pollutions was designed using standard interchangeable DNA parts (BioBricks). An engineered E. coli strain was used to degrade alkanes via β-oxidation in toxic aqueous environments. The respective enzymes from different species showed alkane degradation activity. Additionally, an increased tolerance to n-hexane was achieved by introducing genes from alkane-tolerant bacteria.
JoVE Immunology and Infection
Quantification of Fungal Colonization, Sporogenesis, and Production of Mycotoxins Using Kernel Bioassays
Plant Pathology and Microbiology, Texas A&M University
The devastation of cereal crops by seed-infecting fungi has prompted numerous research efforts to better understand plant-pathogen interactions. To study seed-fungal interactions in a laboratory setting, we developed a robust method for the quantification of fungal reproduction, biomass, and mycotoxin contamination using kernel bioassays.
JoVE Immunology and Infection
Passive Administration of Monoclonal Antibodies Against H. capsulatum and Others Fungal Pathogens
Department of Microbiology and Immunology, Albert Einstein College of Medicine
C57BL/6 mice have been used to study Hc pathogenesis and provide the best model. We are exploring the potential benefits of humoral immunity against this fungus and generated several mAbs [to histone H2B and a heat shock protein 60kDa] that we tested for their protective efficacy after intraperitoneal administration.
JoVE General
Virus-induced Gene Silencing (VIGS) in Nicotiana benthamiana and Tomato
1Plant Pathology and Plant-Microbe Biology, Cornell University, 2Boyce Thompson Institute for Plant Research
Description of a virus-induced gene silencing (VIGS) method for knock-down of gene expression in Nicotiana benthamiana and tomato.
JoVE Chemistry
Rapid Colorimetric Assays to Qualitatively Distinguish RNA and DNA in Biomolecular Samples
Department of Chemistry, University of Virginia
A suite of colorimetric assays is described for rapidly distinguishing protein, RNA, DNA, and reducing sugars in potentially heterogeneous biomolecular samples.
JoVE Immunology and Infection
Neutrophil Extracellular Traps: How to Generate and Visualize Them
1Core Facility Microscopy, Max Planck Institute for Infection Biology, 2Cellular Microbiology, Max Planck Institute for Infection Biology
Neutrophil Extracellular Traps (NETs) are an important innate immune mechanism to fight pathogenic bacteria, fungi and parasites. Here we describe methods to isolate neutrophil granulocytes from human blood and to activate them to form NETs. We present preparation techniques to visualize NETs in light and electron microscopy.
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