Die Autoren bedanken sich bei Kenntnis der technischen von David Briles (University of Alabama in Birmingham, AL, USA) zu beraten. Wir möchten Yvette Chen, der Animal Welfare Officer von The University of Melbourne, und David Taylor, der Animal Facility Manager, für Anregungen und Diskussionen über Tierschutz und-ethik und Entwicklung von Interventionsstrategien Kriterien und humane Endpunkte für die beschriebenen Versuche danken in diesem Manuskript. Odilia Wijburg und Patrick Lesen von einem NHMRC RD Wright Fellowship unterstützt werden, ist Kirsty Short von einem GSK Postgraduate Unterstützung zu gewähren und eine Puzey Stipendium unterstützt.

<ol>
	<li>Brundage, J. F., Shanks, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deaths+from+bacterial+pneumonia+during+1918-19+influenza+pandemic.">Deaths from bacterial pneumonia during 1918-19 influenza pandemic.</a> Emerg Infect Dis. 14, 1193-1199 (2008).</li><li>Petersdorf, R. G., Fusco, J. J., Harter, D. H., Albrink, W. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulmonary+infections+complicating+Asian+influenza.">Pulmonary infections complicating Asian influenza.</a> AMA Arch Intern Med. 103, 262-272 (1959).</li><li>Diavatopoulos, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influenza+A+virus+facilitates+Streptococcus+pneumoniae+transmission+and+disease.">Influenza A virus facilitates Streptococcus pneumoniae transmission and disease.</a> Faseb J. , (2010).</li><li>Orihuela, C. J., Gao, G., Francis, K. P., Yu, J., Tuomanen, E. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue-specific+contributions+of+pneumococcal+virulence+factors+to+pathogenesis.">Tissue-specific contributions of pneumococcal virulence factors to pathogenesis.</a> J Infect Dis. 190, 1661-1669 (2004).</li><li>Kadurugamuwa, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+monitoring+of+pneumococcal+meningitis+and+evaluation+of+treatment+efficacy+in+an+experimental+mouse+model.">Noninvasive monitoring of pneumococcal meningitis and evaluation of treatment efficacy in an experimental mouse model.</a> Mol Imaging. 4, 137-142 (2005).</li><li>Smith, M. W., Schmidt, J. E., Rehg, J. E., Orihuela, C. J., McCullers, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+pro-+and+anti-inflammatory+molecules+in+a+mouse+model+of+pneumococcal+pneumonia+after+influenza.">Induction of pro- and anti-inflammatory molecules in a mouse model of pneumococcal pneumonia after influenza.</a> Comp Med. 57, 82-89 (2007).</li><li>Owen, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nasal-associated+lymphoid+tissue+and+olfactory+epithelium+as+portals+of+entry+for+Burkholderia+pseudomallei+in+murine+melioidosis.">Nasal-associated lymphoid tissue and olfactory epithelium as portals of entry for Burkholderia pseudomallei in murine melioidosis.</a> J Infect Dis. 199, 1761-1770 (2009).</li><li>Luker, G. D., Leib, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Luciferase+real-time+bioluminescence+imaging+for+the+study+of+viral+pathogenesis.">Luciferase real-time bioluminescence imaging for the study of viral pathogenesis.</a> Methods Mol Biol. 292, 285-296 (2005).</li><li>Hutchens, M., Luker, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+bioluminescence+imaging+to+the+study+of+infectious+diseases.">Applications of bioluminescence imaging to the study of infectious diseases.</a> Cell Microbiol. 9, 2315-2322 (2007).</li></ol>

Die Produktion dieses Video-Artikel wurde von Caliper Life Sciences gefördert.

In-vivo-Bildgebung mit dem IVIS Maschine ist eine einzigartige Methodik, die die Echtzeit-Visualisierung der mikrobiellen Pathogenese 4, 6-9 ermöglicht. Hier zeigen wir die Anwendung dieser Technologie für das Verständnis der Synergismus zwischen S. pneumoniae und Influenza-Virus in Säuglings-Mäusen. Aufgrund der nicht-invasiven Charakter dieser Technik haben wir in der Lage, das Fortschreiten der Infektion in einzelnen Maus im Laufe der Zeit zu überwachen. Dies hat uns ermöglicht, die Kinetik der Pneumokokken-Übertragung unter Zusammenarbeit untergebracht Säugling Mäuse 3-Dokument. Die nicht-invasive Natur dieser Technik ermöglicht es Forschern, weniger Tiere pro Versuch verwenden und so zu verringern Tierversuchen. Es ist auch möglich, die IVIS Maschine benutzen, um die Verbreitung der Infektion, bisher unbekannte Seiten der Infektion im Körper sichtbar zu machen, sowie Websites, die nicht einfach durch Dissektion (wie Mittelohr) abgetastet. Vor Beginn der bildgebenden Experimenten bestätigten wir, dass die Kolonisierung Ebenen der Biolumineszenz EF3030 Belastung vergleichbar Kolonisierung Ebenen der Muttergesellschaft EF3030 Belastung durch die Aufzählung Keimzahl in Gewebehomogenaten wurden. Darüber hinaus haben wir zunächst bestätigt, dass eine Infektion mit Influenza-Virus führte zu einer erhöhten Belastung der Biolumineszenz EF3030 in den Nasenrachenraum von besiedelten Tieren als mit den Eltern EF3030 Stamm (Ergebnisse nicht gezeigt) nachgewiesen. Während die IVIS Technologie ist einfach zu bedienen und erzeugt reproduzierbare und einfach, Daten zu verstehen, müssen Experimente sorgfältig entworfen werden, so dass die Empfindlichkeit und die Nützlichkeit der Technologie maximiert wird. Zum Beispiel ist die Empfindlichkeit der Kamera IVIS durch die Tiefe und die Deckkraft des Gewebes 8, die in unserer Erfahrung, erhöht sich die Nachweisgrenze für Biolumineszenz-Signale aus der Lunge betroffen. Darüber hinaus reduziert dunkles Fell und pigmentierter Haut Lichtdurchlässigkeit um mehr als 10-fach (verglichen mit haarlosen Mäusen) 8. Während der Entwicklung dieser Methode haben wir dieses Protokoll für den Einsatz mit 5 bis 14 Tage alte C57BL / 6 Mäuse optimiert und seit bewiesen, dass IVIS verwendet werden, um Kolonisierung von 20 Tage alten C57BL / 6 Mäuse mit Biolumineszenz S. erkannt werden pneumoniae EF3030. Allerdings kann Signalerkennung erhöht, wenn diese Experimente in nude oder BALB / c Mäusen durchgeführt werden. Dennoch stellt die IVIS Kamera einen neuartigen Ansatz zur Überwachung, zu charakterisieren und schließlich verstehen die in vivo Entwicklung von Pneumokokken-Erkrankungen nach Influenza A-Virus-Infektion.

using bioluminescent imaging to investigate synergism between streptococcus pneumoniae and influenza a virus in infant mice

Während der 1918 Influenza-Virus-Pandemie, die etwa 50 Millionen Menschen weltweit tötete, war die Mehrheit der Todesfälle nicht die Folge einer Infektion mit dem Influenzavirus allein. Stattdessen sind die meisten Menschen gedacht, um eine sekundäre bakterielle Infektion erlegen, vorwiegend durch das Bakterium Streptococcus pneumoniae (Pneumokokken) verursacht. Die synergistische Beziehung zwischen Infektionen, die durch Influenza-Viren und Pneumokokken verursacht hat in der Folge während der 1957 Asian Influenza-Virus-Pandemie beobachtet worden, wie auch bei saisonalen Ausbrüche des Virus (Übersicht in 1, 2). Hier beschreiben wir ein Protokoll verwendet, um den Mechanismus (s), die in einer erhöhten Morbidität beteiligt sein können, als Folge der gleichzeitigen Influenza A-Virus und S. untersuchen pneumoniae Infektion. Wir haben ein Kind Mausmodell entwickelt, um zuverlässig und reproduzierbar zeigen die Auswirkungen des Influenza-Virus Infektion von Mäusen mit S. kolonisiert pneumoniae. Unter Verwendung dieses Protokolls haben wir den ersten Einblick in die Kinetik der Pneumokokken-Übertragung zwischen Co-untergebracht, neugeborenen Mäusen mit in-vivo-Bildgebung 3 vorgesehen.

Watch this Scientific Journal Video about Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice at JoVE.com

Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice

Eine gleichzeitige Infektion mit Influenza A-Virus ist einer der Faktoren bei der Induktion von invasiven Pneumokokken-Erkrankung bei asymptomatischen verwickelt<em&gt; Streptococcus pneumoniae</em&gt; Wagen. Hier beschreiben wir eine Mischinfektion Methode mit Kind Mäusen die Synergie zwischen diesen beiden respiratorischen Erregern zu untersuchen.

Mit Bioluminescent Imaging, um Synergie von Untersuchen Streptococcus pneumoniae Und Influenza A Virus in Infant Mäuse

During the 1918 influenza virus pandemic, which killed approximately 50 million people worldwide, the majority of fatalities were not the result of ...

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Research

JoVE Journal

Immunology and Infection

Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice

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Serie: Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice

Live Cell Imaging of Bacillus subtilis and Streptococcus pneumoniae using Automated Time-lapse Microscopy

During the last few years scientists became increasingly aware that average data obtained from microbial population based experiments are not representative of the behavior, status or phenotype of single cells. Due to this new insight the number of single cell studies rises continuously (for recent reviews see 1,2,3). However, many of the single cell techniques applied do not allow monitoring the development and behavior of one specific single cell in time (e.g. flow cytometry or standard microscopy).
Here, we provide a detailed description of a microscopy method used in several recent studies 4, 5, 6, 7, which allows following and recording (fluorescence of) individual bacterial cells of Bacillus subtilis and Streptococcus pneumoniae through growth and division for many generations. The resulting movies can be used to construct phylogenetic lineage trees by tracing back the history of a single cell within a population that originated from one common ancestor. This time-lapse fluorescence microscopy method cannot only be used to investigate growth, division and differentiation of individual cells, but also to analyze the effect of cell history and ancestry on specific cellular behavior. Furthermore, time-lapse microscopy is ideally suited to examine gene expression dynamics and protein localization during the bacterial cell cycle. The method explains how to prepare the bacterial cells and construct the microscope slide to enable the outgrowth of single cells into a microcolony. In short, single cells are spotted on a semi-solid surface consisting of growth medium supplemented with agarose on which they grow and divide under a fluorescence microscope within a temperature controlled environmental chamber. Images are captured at specific intervals and are later analyzed using the open source software ImageJ.

Live Cell Imaging of Bacillus subtilis and Streptococcus pneumoniae using Automated Time-lapse Microscopy

This protocol provides a step-by-step procedure to monitor single cell behavior of different bacteria in time using automated fluorescence time-lapse microscopy. Furthermore, we provide guidelines how to analyze the microscopy images.

Live Cell Imaging von Bacillus subtilis Und Streptococcus pneumoniae Verwendung von Automated Zeitraffer-Mikroskopie

During the last few years scientists became increasingly aware that average data obtained from microbial population based experiments are not ...

Forschung

Immunologie und Infektion

Bioluminescent Bacterial Imaging In Vivo

This video describes the use of whole body bioluminesce imaging (BLI) for the study of bacterial trafficking in live mice, with an emphasis on the use of bacteria in gene and cell therapy for cancer. Bacteria present an attractive class of vector for cancer therapy, possessing a natural ability to grow preferentially within tumors following systemic administration. Bacteria engineered to express the lux gene cassette permit BLI detection of the bacteria and concurrently tumor sites. The location and levels of bacteria within tumors over time can be readily examined, visualized in two or three dimensions. The method is applicable to a wide range of bacterial species and tumor xenograft types. This article describes the protocol for analysis of bioluminescent bacteria within subcutaneous tumor bearing mice. Visualization of commensal bacteria in the Gastrointestinal tract (GIT) by BLI is also described. This powerful, and cheap, real-time imaging strategy represents an ideal method for the study of bacteria in vivo in the context of cancer research, in particular gene therapy, and infectious disease. This video outlines the procedure for studying lux-tagged E. coli in live mice, demonstrating the spatial and temporal readout achievable utilizing BLI with the IVIS system.

Bioluminescent Bacterial Imaging In Vivo

This article describes the administration of lux-tagged bacteria to mice and subsequent in vivo analysis using IVIS bioluminescence imaging.

Bioluminescent Bakterielle Imaging<em&gt; In Vivo</em

This video describes the use of whole body bioluminesce imaging (BLI) for the study of bacterial trafficking in live mice, with an emphasis on the use of ...

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae

Nasopharyngeal colonization by Streptococcus pneumoniae is a prerequisite to invasion to the lungs or bloodstream1. This organism is capable of colonizing the mucosal surface of the nasopharynx, where it can reside, multiply and eventually overcome host defences to invade to other tissues of the host. Establishment of an infection in the normally lower respiratory tract results in pneumonia. Alternatively, the bacteria can disseminate into the bloodstream causing bacteraemia, which is associated with high mortality rates2, or else lead directly to the development of pneumococcal meningitis. Understanding the kinetics of, and immune responses to, nasopharyngeal colonization is an important aspect of S. pneumoniae infection models.
Our mouse model of intranasal colonization is adapted from human models3 and has been used by multiple research groups in the study of host-pathogen responses in the nasopharynx4-7. In the first part of the model, we use a clinical isolate of S. pneumoniae to establish a self-limiting bacterial colonization that is similar to carriage events in human adults. The procedure detailed herein involves preparation of a bacterial inoculum, followed by the establishment of a colonization event through delivery of the inoculum via an intranasal route of administration. Resident macrophages are the predominant cell type in the nasopharynx during the steady state. Typically, there are few lymphocytes present in uninfected mice8, however mucosal colonization will lead to low- to high-grade inflammation (depending on the virulence of the bacterial species and strain) that will result in an immune response and the subsequent recruitment of host immune cells. These cells can be isolated by a lavage of the tracheal contents through the nares, and correlated to the density of colonization bacteria to better understand the kinetics of the infection.

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae

Colonization of the murine nasopharynx with Streptococcus pneumoniae and the subsequent extraction of adherent or recruited cells is described. This technique involves flushing the nasopharynx and collection of the fluid through the nares and is adaptable for various readouts, including differential cell quantification and analysis of mRNA expression in situ.

Charakterisierung von Entzündungsreaktionen während der intranasalen Kolonisation mit Streptococcus pneumoniae

Nasopharyngeal colonization by Streptococcus pneumoniae is a prerequisite to invasion to the lungs or bloodstream1. This organism is capable of colonizing ...

Monitoring Changes in Membrane Polarity, Membrane Integrity, and Intracellular Ion Concentrations in Streptococcus pneumoniae Using Fluorescent Dyes

Membrane depolarization and ion fluxes are events that have been studied extensively in biological systems due to their ability to profoundly impact cellular functions, including energetics and signal transductions. While both fluorescent and electrophysiological methods, including electrode usage and patch-clamping, have been well developed for measuring these events in eukaryotic cells, methodology for measuring similar events in microorganisms have proven more challenging to develop given their small size in combination with the more complex outer surface of bacteria shielding the membrane. During our studies of death-initiation in Streptococcus pneumoniae (pneumococcus), we wanted to elucidate the role of membrane events, including changes in polarity, integrity, and intracellular ion concentrations. Searching the literature, we found that very few studies exist. Other investigators had monitored radioisotope uptake or equilibrium to measure ion fluxes and membrane potential and a limited number of studies, mostly in Gram-negative organisms, had seen some success using carbocyanine or oxonol fluorescent dyes to measure membrane potential, or loading bacteria with cell-permeant acetoxymethyl (AM) ester versions of ion-sensitive fluorescent indicator dyes. We therefore established and optimized protocols for measuring membrane potential, rupture, and ion-transport in the Gram-positive organism S. pneumoniae. We developed protocols using the bis-oxonol dye DiBAC4(3) and the cell-impermeant dye propidium iodide to measure membrane depolarization and rupture, respectively, as well as methods to optimally load the pneumococci with the AM esters of the ratiometric dyes Fura-2, PBFI, and BCECF to detect changes in intracellular concentrations of Ca2+, K+, and H+, respectively, using a fluorescence-detection plate reader. These protocols are the first of their kind for the pneumococcus and the majority of these dyes have not been used in any other bacterial species. Though our protocols have been optimized for S. pneumoniae, we believe these approaches should form an excellent starting-point for similar studies in other bacterial species.

Monitoring Changes in Membrane Polarity, Membrane Integrity, and Intracellular Ion Concentrations in Streptococcus pneumoniae Using Fluorescent Dyes

Unlike that seen for eukaryotes, there is a paucity of studies that detail membrane depolarization and ion concentration changes in bacteria, primarily as their small size makes conventional methods of measurement difficult. Here, we detail protocols for monitoring such events in the significant Gram-positive pathogen Streptococcus pneumoniae utilizing fluorescence techniques.

Überwachen von Änderungen in Membran-Polarity, Membrane Integrity und intrazelluläre Ionenkonzentrationen in<em&gt; Streptococcus pneumoniae</em&gt; Verwenden von Fluoreszenzfarbstoffen

Membrane depolarization and ion fluxes are events that have been studied extensively in biological systems due to their ability to profoundly impact ...

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

There are over 90 different capsular serotypes of Streptococcus pneumoniae (the pneumococcus). As well as being a tool for understanding pneumococcal epidemiology, capsular serotyping can provide useful information for vaccine efficacy and impact studies.&#160;The Quellung reaction is the gold standard method for pneumococcal capsular serotyping. The method involves testing a pneumococcal cell suspension with pooled and specific antisera directed against the capsular polysaccharide. The antigen-antibody reactions are observed microscopically. The protocol has three main steps: 1) preparation of a bacterial cell suspension, 2) mixing of cells and antisera on a glass slide, and 3) reading the Quellung reaction using a microscope. The Quellung reaction is reasonably simple to perform and can be applied wherever a suitable microscope and antisera are available.

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

The Quellung reaction is the gold standard technique for serotyping Streptococcus pneumoniae. This technique utilizes a microscope and specific pneumococcal antisera and is commonly used in reference and research laboratories worldwide.

Kapsel Serotypisierung von<em&gt; Streptococcus pneumoniae</em&gt; Verwenden der Quellung Reaktion

There are over 90 different capsular serotypes of Streptococcus pneumoniae (the pneumococcus). As well as being a tool for understanding pneumococcal ...

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination

Latex agglutination reagents are widely used in microbial diagnosis, identification and serotyping. Streptococcus pneumoniae (the pneumococcus) is a major cause of morbidity and mortality world-wide. Current vaccines target the pneumococcal capsule, and there are over 90 capsular serotypes. Serotyping pneumococcal isolates is therefore important for assessing the impact of vaccination programs and for epidemiological purposes. The World Health Organization has recommended latex agglutination as an alternative method to the &#8216;gold standard&#8217; Quellung test for serotyping pneumococci. Latex agglutination is a relatively simple, quick and inexpensive method; and is therefore suitable for resource-poor settings as well as laboratories with high-volume workloads. Latex agglutination reagents can be prepared in-house utilizing commercially-sourced antibodies that are passively attached to latex particles. This manuscript describes a method of production and quality control of latex agglutination reagents, and details a sequential testing approach which is time- and cost-effective. 
This method of production and quality control may also be suitable for other testing purposes.

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination

Latex agglutination testing is a simple, rapid and inexpensive method for serotyping Streptococcus pneumoniae, and has also been widely applied in diagnostic microbiology. This manuscript describes the in-house production of latex agglutination reagents, quality control procedures and the application of this technique to pneumococcal serotyping.

Kapsel Serotypisierung<em&gt; Streptococcus pneumoniae</em&gt; Durch Latexagglutination

Latex agglutination reagents are widely used in microbial diagnosis, identification and serotyping. Streptococcus pneumoniae (the pneumococcus) is a major ...

Influenza Virus Propagation in Embryonated Chicken Eggs

Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous emergence of new influenza virus strains due to mutation and re-assortment complicates the control of the virus and necessitates the permanent development of novel drugs and vaccines. The laboratory-based study of influenza requires a reliable and cost-effective method for the propagation of the virus. Here, a comprehensive protocol is provided for influenza A virus propagation in fertile chicken eggs, which consistently yields high titer viral stocks. In brief, serum pathogen-free (SPF) fertilized chicken eggs are incubated at 37 &#176;C and 55-60% humidity for 10 &#8211; 11 days. Over this period, embryo development can be easily monitored using an egg candler. Virus inoculation is carried out by injection of virus stock into the allantoic cavity using a needle. After 2 days of incubation at 37 &#176;C, the eggs are chilled for at least 4 hr at 4 &#176;C. The eggshell above the air sac and the chorioallantoic membrane are then carefully opened, and the allantoic fluid containing the virus is harvested. The fluid is cleared from debris by centrifugation, aliquoted and transferred to -80 &#176;C for long-term storage. The large amount (5-10 ml of virus-containing fluid per egg) and high virus titer which is usually achieved with this protocol has made the usage of eggs for virus preparation our favorable method, in particular for in vitro studies which require large quantities of virus in which high dosages of the same virus stock are needed.

Fertile chicken eggs are widely used to produce large amounts of human influenza A virus as they provide a convenient and cost-effective system to prove high yields of virus.

Influenza Virus Vermehrung in embryonierten Hühnereiern

Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous ...

Neutrophil Isolation and Analysis to Determine their Role in Lymphoma Cell Sensitivity to Therapeutic Agents

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of inflammation. They are key players in the innate immune system and play major roles in cancer biology. Neutrophils have been proposed as key mediators of malignant transformation, tumor progression, angiogenesis and in the modulation of the antitumor immunity; through their release of soluble factors or their interaction with tumor cells. To characterize the specific functions of neutrophils, a fast and reliable method is coveted for in vitro isolation of neutrophils from human blood. Here, a density gradient separation method is demonstrated to isolate neutrophils as well as mononuclear cells from the blood. The procedure consists of layering the density gradient solution such as Ficoll carefully above the diluted blood obtained from patients diagnosed with chronic lymphocytic leukemia (CLL), followed by centrifugation, isolation of mononuclear layer, separation of neutrophils from RBCsby dextran then lysis of residual erythrocytes. This method has been shown to isolate neutrophils &#8805; 90 % pure. To mimic the tumor microenvironment, 3-dimensional (3D) experiments were performed using basement membrane matrix such as Matrigel. Given the short half-life of neutrophils in vitro, 3D experiments with fresh human neutrophils cannot be performed. For this reason promyelocytic HL60 cells are differentiated along the granulocytic pathway using the differentiation inducers dimethyl sulfoxide (DMSO) and retinoic acid (RA). The aim of our experiments is to study the role of neutrophils on the sensitivity of lymphoma cells to anti-lymphoma agents. However these methods can be generalized to study the interactions of neutrophils or neutrophil-like cells with a large range of cell types in different situations.

Neutrophils are the most abundant type of white blood cells. The isolation of neutrophils from human blood by density gradient separation method and the differentiation of human promyelocytic (HL60) cells along the granulocytic pathway are described here; to test their role on sensitivity of lymphoma cells to anti-lymphoma agents.

Neutrophilen-Isolierung und Analyse zur Bestimmung ihrer Rolle in der Lymphom-Zellempfindlichkeit therapeutische Mittel

Neutrophils are the most abundant (40% to 75%) type of white blood cells and among the first inflammatory cells to migrate towards the site of ...

Influenza A Virus Studies in a Mouse Model of Infection

Influenza viruses cause over 500,000 deaths worldwide1 and are associated with an annual cost of 12 - 14 billion USD in the United States alone considering direct medical and hospitalization expenses and work absenteeism2. Animal models are crucial in Influenza A virus (IAV) studies to evaluate viral pathogenesis, host-pathogen interactions, immune responses, and the efficacy of current and/or novel vaccine approaches as well as antivirals. Mice are an advantageous small animal model because their immune system is evolutionarily similar to that found in humans, they are available from commercial vendors as genetically identical subjects, there are multiple strains that can be exploited to evaluate the genetic basis of infections, and they are relatively inexpensive and easy to manipulate. To recapitulate IAV infection in humans via the airways, mice are first anesthetized prior to intranasal inoculation with infectious IAVs under proper biosafety containment. After infection, the pathogenesis of IAVs is determined by monitoring daily the morbidity (body weight loss) and mortality (survival) rate. In addition, viral pathogenesis can also be evaluated by assessing virus replication in the upper (nasal mucosa) or lower (lungs) respiratory tract of infected mice. Humoral responses upon IAV infection can be rapidly evaluated by non-invasive bleeding and secondary antibody detection assays aimed at detecting the presence of total or neutralizing antibodies. Here, we describe the common methods used to infect mice intranasally (i.n) with IAV and evaluate pathogenesis, humoral immune responses and protection efficacy.

Influenza A viruses (IAVs) are important human respiratory pathogens. To understand the pathogenicity of IAVs and to perform preclinical testing of novel vaccine approaches, animal models mimicking human physiology are required. Here, we describe techniques to evaluate IAV pathogenesis, humoral responses and vaccine efficacy using a mouse model of infection.

Influenza-A-Virus-Studien in einem Mausmodell der Infektion

Influenza viruses cause over 500,000 deaths worldwide1 and are associated with an annual cost of 12 - 14 billion USD in the United States alone ...

Measuring Influenza Neutralizing Antibody Responses to A(H3N2) Viruses in Human Sera by Microneutralization Assays Using MDCK-SIAT1 Cells

Neutralizing antibodies against hemagglutinin (HA) of influenza viruses are considered the main immune mechanism that correlates with protection for influenza infections. Microneutralization (MN) assays are often used to measure neutralizing antibody responses in human sera after influenza vaccination or infection. Madine Darby Canine Kidney (MDCK) cells are the commonly used cell substrate for MN assays. However, currently circulating 3C.2a and 3C.3a A(H3N2) influenza viruses have acquired altered receptor binding specificity. The MDCK-SIAT1 cell line with increased &#945;-2,6 sialic galactose moieties on the surface has proven to provide improved infectivity and more faithful replications than conventional MDCK cells for these contemporary A(H3N2) viruses. Here, we describe a MN assay using MDCK-SIAT1 cells that has been optimized to quantify neutralizing antibody titers to these contemporary A(H3N2) viruses. In this protocol, heat inactivated sera containing neutralizing antibodies are first serially diluted, then incubated with 100 TCID50/well of influenza A(H3N2) viruses to allow antibodies in the sera to bind to the viruses. MDCK-SIAT1 cells are then added to the virus-antibody mixture, and incubated for 18 - 20 h at 37 &#176;C, 5% CO2 to allow A(H3N2) viruses to infect MDCK-SIAT1 cells. After overnight incubation, plates are fixed and the amount of virus in each well is quantified by an enzyme-linked immunosorbent assay (ELISA) using anti-influenza A nucleoprotein (NP) monoclonal antibodies. Neutralizing antibody titer is defined as the reciprocal of the highest serum dilution that provides &#8805;50% inhibition of virus infectivity.

Measuring Influenza Neutralizing Antibody Responses to AH3N2 Viruses in Human Sera by Microneutralization Assays Using MDCK-SIAT1 Cells

Influenza neutralizing antibodies correlate with protection of influenza infections. Microneutralization assays measure neutralizing antibodies in human sera and are often used for influenza human serology. We describe a microneutralization assay using MDCK-SIAT1 cells to measure neutralizing antibody titers to contemporary 3C.2a and 3C.3a A(H3N2) viruses following influenza vaccination or infection.

Messung der Influenza neutralisierenden Antikörperantworten gegen a/H3N2-Viren im menschlichen Serum von Microneutralization Assays mit MDCK-SIAT1 Zellen

Neutralizing antibodies against hemagglutinin (HA) of influenza viruses are considered the main immune mechanism that correlates with protection for ...