وقد أيد هذا الاستعراض من قبل المعاهد الوطنية للصحة المنح ، AI074420 - 02 ، جائزة الباحث بوروز ويلكوم ، Hirschl الجوائز شهادة العلماء إلى BKC ومركز جبهة الخلاص الوطني للعلوم والتكنولوجيا بيوفوتونيك ، الاتفاق التعاوني PHY012099 ، والنظام الصحي UCD جائزة البحوث لTH UCD CTSC NCRR ULRR024146.

<ol>
	<li>Blanco, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+level+of+coreceptor-independent+HIV+transfer+induced+by+contacts+between+primary+CD4+T+cells.">High level of coreceptor-independent HIV transfer induced by contacts between primary CD4 T cells.</a> J Biol Chem. 279, 51305-51314 (2004).</li><li>Sourisseau, M., Sol-Foulon, N., Porrot, F., Blanchet, F., Schwartz, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inefficient+human+immunodeficiency+virus+replication+in+mobile+lymphocytes.">Inefficient human immunodeficiency virus replication in mobile lymphocytes.</a> J Virol. 81, 1000-1012 (2007).</li><li>Jolly, C., Kashefi, K., Hollinshead, M., Sattentau, Q. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HIV-1+cell+to+cell+transfer+across+an+Env-induced,+actin-dependent+synapse.">HIV-1 cell to cell transfer across an Env-induced, actin-dependent synapse.</a> J Exp Med. 199, 283-293 (2004).</li><li>Hubner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequence+of+human+immunodeficiency+virus+type+1+(HIV-1)+Gag+localization+and+oligomerization+monitored+with+live+confocal+imaging+of+a+replication-competent,+fluorescently+tagged+HIV-1.">Sequence of human immunodeficiency virus type 1 (HIV-1) Gag localization and oligomerization monitored with live confocal imaging of a replication-competent, fluorescently tagged HIV-1.</a> J Virol. 81, 12596-12607 (2007).</li><li>Hubner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+3D+video+microscopy+of+HIV+transfer+across+T+cell+virological+synapses.">Quantitative 3D video microscopy of HIV transfer across T cell virological synapses.</a> Science. 323, 1743-1747 (2009).</li></ol>

الإعلان عن أي تضارب في المصالح.

نحن هنا وصف طريقة بسيطة لتصور نقل الفيروس من خلية خلية. الأبحاث الحديثة من مختبرنا وغيرها &#39;تشير إلى أن هذا قد يكون الطريقة السائدة لانتشار الفيروس بين خلايا تي. وصف الأسلوب هنا يوظف النموذج المؤتلف من فيروس نقص المناعة البشرية ، ودعا فيروس نقص المناعة البشرية ، iGFP الكمامة ، والذي يحمل علامة ترميز وراثيا ببروتين أخضر في الهيكلية الأساسية الكمامة ، والبروتين. وبسبب المستويات العالية للإنتاج في كل GFP جسيمات الفيروس ، وهذا تكرار استنساخ فيروس نقص المناعة البشرية المختصة ، تمكن الباحثون لتعقب جزيئات الفيروس الفردية في الوقت الحقيقي. هذا الفيروس ينبغي أن تكون مفيدة خاصة في الدراسات المتعلقة بنقل وتجميع خلية خلية من فيروس نقص المناعة البشرية. نقل فيروس نقص المناعة البشرية من قبل خلية خلية ونقل عالية الكفاءة. خلال ثلاث ساعات شارك في الثقافة ، ونحن نرى الروتينية الفيروس نقلت إلى 20-30 ٪ من الخلايا التائية الابتدائية ، والمقررة من قبل التدفق الخلوي. وتعتبر الكفاءة النوعية مماثلة خلال تصوير الخلايا الحية. خلايا تي المصابة فيروسي بدء تشكيل نقاط الاشتباك العصبي مع الخلايا غير المصابة T الأولية على الفور تقريبا بعد الشروع في الثقافة المشتركة. للاهتمام ، وليس كل الخلايا الأولية T قادرة على التفاعل مع الخلايا المصابة بفيروس نقص المناعة البشرية Jurkat رغم التفاعلات القسري مع ملاقط الليزر (الملاحظات غير المنشورة ، وجنرال موتورز). وفيروس نقص المناعة البشرية الكمامة - iGFP ستكون بلا شك مفيدة لتحديد مجموعات فرعية الخلايا التائية التي هي الأكثر عرضة للخلية خلية نقل ، سواء في المختبر والمجراة.

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		<th>Catalogue Number</th>
		<th>Comment</th>
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<tr>
<td>Jurkat T Cells</td>
<td>&nbsp;</td>
<td>ATCC</td>
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<td>Leukocyte buffy coats from whole blood</td>
<td>&nbsp;</td>
<td>New York Blood Center</td>
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<td>RPMI</td>
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<td>Sigma</td>
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<td>Fetal Bovine Serum</td>
<td>&nbsp;</td>
<td>Hyclone</td>
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<td>Penicillin/Streptomycin</td>
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<td>Invitrogen</td>
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<td>Nucleofector System and Solution V</td>
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<td>Lonza</td>
<td>&nbsp;</td>
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<td>EndoFree Maxi Prep Kits</td>
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<td>Qiagen</td>
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<td>HIV Gag-iGFP plasmid</td>
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<td>Chen Laboratory</td>
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<td>CD4+ T Cell Isolation Kit</td>
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<td>Miltenyi Biotec</td>
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<td>Ficoll-Paque</td>
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<td>GE Healthcare</td>
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<td>Celltracker/CellTrace Dyes</td>
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<td>Invitrogen</td>
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<td>CO2-Independent Media</td>
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<td>Invitrogen</td>
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<td>Imaging Chambers</td>
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<td>Ibidi</td>
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<td>Olympus IX-71 Inverted Microscope</td>
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<td>Olympus</td>
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<td>PlanApo N 1.42NA 60X oil objective</td>
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<td>Olympus</td>
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<td>Innova 70C ArKr ion gas laser</td>
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<td>Coherent </td>
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<td>CSU-10 Nipkow-type spinning disk confocal unit</td>
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<td>Yokogawa</td>
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<td>Di01-T405/488/568/647-13x15x0.5 dichroic beamsplitter</td>
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<td>Semrock</td>
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<tr>
<td>525/50 bandpass filter</td>
<td>&nbsp;</td>
<td>Semrock</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
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<td>iXon+ 897 electron-multiplied charged coupled devise camera</td>
<td>&nbsp;</td>
<td>Andor</td>
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<td>ASI 400 Thermostatic Heater</td>
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<td>Nevtek</td>
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visualizing cell-to-cell transfer of hiv using fluorescent clones of hiv and live confocal microscopy

التفجير بواسطة بروتين الفلورية الخضراء للبروتينات المفضلة لديهم ، وعلماء الأحياء والآن لدينا القدرة على دراسة العمليات الخلوية الحية معقدة باستخدام المجهر مضان الفيديو. لتتبع تحركات بروتين فيروس نقص المناعة البشرية الأساسية خلال خلية الى خلية من انتقال فيروس نقص المناعة البشرية ، لدينا GFP الموسومة البروتين الكمامة في سياق استنساخ الجزيئية المعدية فيروس نقص المناعة البشرية ، ودعا فيروس نقص المناعة البشرية الكمامة - iGFP. ندرس هذا استنساخ الفيروسية باستخدام المجهر مبائر الفيديو. في التجربة التالية تصور ، ونحن transfect خلية T الإنسان تمشيا مع فيروس نقص المناعة البشرية ، iGFP الكمامة ، ونحن نستخدم CD4 المعافين fluorescently المسمى + الخلايا التائية لتكون بمثابة الخلايا المستهدفة للفيروس. استخدام تسميات مختلفة الفلورسنت يمكننا بسهولة تتبع الإنتاج الفيروسية وهياكل النقل عبر نقاط الاشتباك العصبي بين الخلايا يسمى الفيروسية. بسيطة غرف الغاز نفاذية التصوير يسمح لنا أن نلاحظ المشابك مع مبائر المجهري المباشر من دقائق إلى أيام. ويمكن استخدام هذه الأساليب لتتبع البروتينات الفيروسية لأنها تتحرك في خلية واحدة من لالمقبل.

Watch this Scientific Journal Video about Visualizing Cell-to-cell Transfer of HIV using Fluorescent Clones of HIV and Live Confocal Microscopy at JoVE.com

Visualizing Cell-to-cell Transfer of HIV using Fluorescent Clones of HIV and Live Confocal Microscopy

تصور هذه التجربة هو بمثابة دليل لاستخدام استنساخ الفلورسنت لفيروس نقص المناعة الجزيئية للعيش تجارب التصوير مبائر.

تصور الخلية إلى خلية نقل فيروس نقص المناعة البشرية باستخدام النسخ نيون فيروس نقص المناعة البشرية ومتحد البؤر المجهري لايف

By fusing the green fluorescent protein to their favorite proteins, biologists now have the ability to study living complex cellular processes using ...

visualizing-cell-to-cell-transfer-hiv-using-fluorescent-clones-hiv

Research

JoVE Journal

Immunology and Infection

16.3K Views.  Mount Sinai School of Medicine. تصور هذه التجربة هو بمثابة دليل لاستخدام استنساخ الفلورسنت لفيروس نقص المناعة الجزيئية للعيش تجارب التصوير مبائر.

Video: Visualizing Cell-to-cell Transfer of HIV using Fluorescent Clones of HIV and Live Confocal Microscopy

Specific Marking of HIV-1 Positive Cells using a Rev-dependent Lentiviral Vector Expressing the Green Fluorescent Protein

Most of HIV-responsive expression vectors are based on the HIV promoter, the long terminal repeat (LTR). While responsive to an early HIV protein, Tat, the LTR is also responsive to cellular activation states and to the local chromatin activity where the integration has occurred. This can result in high HIV-independent activity, and has restricted the usefulness of LTR-based reporter to mark HIV positive cells 1,2,3. Here, we constructed an expression lentiviral vector that possesses, in addition to the Tat-responsive LTR, numerous HIV DNA sequences that include the Rev-response element and HIV splicing sites 4,5,6. The vector was incorporated into a lentiviral reporter virus, permitting highly specific detection of replicating HIV in living cell populations. The activity of the vector was measured by expression of the green fluorescence protein (GFP). The application of this vector as reported here offers a novel alternative approach to existing methods, such as in situ PCR or HIV antigen staining, to identify HIV-positive cells. The vector can also express therapeutic genes for basic or clinical experimentation to target HIV-positive cells.

We have developed a lentiviral vector that possesses, in addition to the Tat-responsive LTR, the Rev-response element (RRE) that can regulate reporter gene expression in an HIV-1 Tat- and Rev-dependent fashion. The vector permits the specific detection of replicating HIV in living cells via the expression of GFP.

تمييز خلايا محددة HIV - 1 الإيجابية باستخدام المتجهات التي تعتمد على رؤيا Lentiviral وإذ تعرب عن البروتين الأخضر نيون

Most of HIV-responsive expression vectors are based on the HIV promoter, the long terminal repeat (LTR). While responsive to an early HIV protein, Tat, ...

Genotypic Inference of HIV-1 Tropism Using Population-based Sequencing of V3

Background: Prior to receiving a drug from CCR5-antagonist class in HIV therapy, a patient must undergo an HIV tropism test to confirm that his or her viral population uses the CCR5 coreceptor for cellular entry, and not an alternative coreceptor. One approach to tropism testing is to examine the sequence of the V3 region of the HIV envelope, which interacts with the coreceptor.
Methods: Viral RNA is extracted from blood plasma. The V3 region is amplified in triplicate with nested reverse transcriptase-PCR. The amplifications are then sequenced and analyzed using the software, RE_Call. Sequences are then submitted to a bioinformatic algorithm such as geno2pheno to infer viral tropism from the V3 region. Sequences are inferred to be non-R5 if their geno2pheno false positive rate falls below 5.75%. If any one of the three sequences from a sample is inferred to be non-R5, the patient is unlikely to respond to a CCR5-antagonist.

HIV tropism can be inferred from the V3 region of the viral envelope. V3 is PCR amplified in triplicate using nested RT-PCR, sequenced, and interpreted using bioinformatic software. Samples with with 1 or more sequence(s) with low g2P scores are classified as non-R5 virus.

الاستدلال الوراثي من HIV - 1 Tropism باستخدام السكان على أساس تسلسل V3

Background: Prior to receiving a drug from CCR5-antagonist class in HIV therapy, a patient must undergo an HIV tropism test to confirm that his or her ...

Determination of Molecular Structures of HIV Envelope Glycoproteins using Cryo-Electron Tomography and Automated Sub-tomogram Averaging

Since its discovery nearly 30 years ago, more than 60 million people have been infected with the human immunodeficiency virus (HIV) <a href="http://www.usaid.gov">(www.usaid.gov)</a>. The virus infects and destroys CD4+ T-cells thereby crippling the immune system, and causing an acquired immunodeficiency syndrome (AIDS) 2. Infection begins when the HIV Envelope glycoprotein "spike" makes contact with the CD4 receptor on the surface of the CD4+ T-cell. This interaction induces a conformational change in the spike, which promotes interaction with a second cell surface co-receptor 5,9. The significance of these protein interactions in the HIV infection pathway makes them of profound importance in fundamental HIV research, and in the pursuit of an HIV vaccine.
The need to better understand the molecular-scale interactions of HIV cell contact and neutralization motivated the development of a technique to determine the structures of the HIV spike interacting with cell surface receptor proteins and molecules that block infection. Using cryo-electron tomography and 3D image processing, we recently demonstrated the ability to determine such structures on the surface of native virus, at &tilde;20 &Aring; resolution 9,14. This approach is not limited to resolving HIV Envelope structures, and can be extended to other viral membrane proteins and proteins reconstituted on a liposome. In this protocol, we describe how to obtain structures of HIV envelope glycoproteins starting from purified HIV virions and proceeding stepwise through preparing vitrified samples, collecting, cryo-electron microscopy data, reconstituting and processing 3D data volumes, averaging and classifying 3D protein subvolumes, and interpreting results to produce a protein model. The computational aspects of our approach were adapted into modules that can be accessed and executed remotely using the Biowulf GNU/Linux parallel processing cluster at the NIH <a href="http://biowulf.nih.gov">(http://biowulf.nih.gov)</a>. This remote access, combined with low-cost computer hardware and high-speed network access, has made possible the involvement of researchers and students working from school or home.

The protocol describes a high-throughput approach to determining structures of membrane proteins using cryo-electron tomography and 3D image processing. It covers the details of specimen preparation, data collection, data processing and interpretation, and concludes with the production of a representative target for the approach, the HIV-1 Envelope glycoprotein. These computational procedures are designed in a way that enables researchers and students to work remotely and contribute to data processing and structural analysis.

تحديد الهياكل الجزيئية لفيروس نقص المناعة البشرية جليكوبروتينات مغلف باستخدام البرد الكترون والتصوير المقطعي الآلي متوسط ​​الفرعية صورة مقطعية

Since its discovery nearly 30 years ago, more than 60 million people have been infected with the human immunodeficiency virus (HIV) (www.usaid.gov). The ...

Prediction of HIV-1 Coreceptor Usage (Tropism) by Sequence Analysis using a Genotypic Approach

Maraviroc (MVC) is the first licensed antiretroviral drug from the class of coreceptor antagonists. It binds to the host coreceptor CCR5, which is used by the majority of HIV strains in order to infect the human immune cells (Fig. 1). Other HIV isolates use a different coreceptor, the CXCR4. Which receptor is used, is determined in the virus by the Env protein (Fig. 2). Depending on the coreceptor used, the viruses are classified as R5 or X4, respectively. MVC binds to the CCR5 receptor inhibiting the entry of R5 viruses into the target cell. During the course of disease, X4 viruses may emerge and outgrow the R5 viruses. Determination of coreceptor usage (also called tropism) is therefore mandatory prior to administration of MVC, as demanded by EMA and FDA. 
The studies for MVC efficiency MOTIVATE, MERIT and 1029 have been performed with the Trofile assay from Monogram, San Francisco, U.S.A. This is a high quality assay based on sophisticated recombinant tests. The acceptance for this test for daily routine is rather low outside of the U.S.A., since the European physicians rather tend to work with decentralized expert laboratories, which also provide concomitant resistance testing. These laboratories have undergone several quality assurance evaluations, the last one being presented in 20111.
For several years now, we have performed tropism determinations based on sequence analysis from the HIV env-V3 gene region (V3)2. This region carries enough information to perform a reliable prediction. 
The genotypic determination of coreceptor usage presents advantages such as: shorter turnover time (equivalent to resistance testing), lower costs, possibility to adapt the results to the patients' needs and possibility of analysing clinical samples with very low or even undetectable viral load (VL), particularly since the number of samples analysed with VL&lt;1000 copies/&mu;l roughly increased in the last years (Fig. 3).
The main steps for tropism testing (Fig. 4) demonstrated in this video: 
1. Collection of a blood sample 
 2. Isolation of the HIV RNA from the plasma and/or HIV proviral DNA from blood mononuclear cells 
 3. Amplification of the env region 
 4. Amplification of the V3 region 
 5. Sequence reaction of the V3 amplicon 
 6. Purification of the sequencing samples 
 7. Sequencing the purified samples 
 8. Sequence editing 
 9. Sequencing data interpretation and tropism prediction

Prediction of HIV-1 Coreceptor Usage Tropism by Sequence Analysis using a Genotypic Approach

The prediction of the coreceptor usage of HIV-1 is required for the administration of a new class of antiretroviral drugs, i.e. coreceptor antagonists. It can be performed by sequence analysis of the env gene and subsequent interpretation through an internet based interpretation system (geno2pheno[coreceptor]).

التنبؤ الإشتخدام HIV-1 Coreceptor (Tropism) من خلال تحليل تسلسل الوراثي باستخدام نهج

Maraviroc (MVC) is the first licensed antiretroviral drug from the class of coreceptor antagonists. It binds to the host coreceptor CCR5, which is used by ...

In vitro Uncoating of HIV-1 Cores

The genome of the retroviruses is encased in a capsid surrounded by a lipid envelope. For lentiviruses, such as HIV-1, the conical capsid shell is composed of CA protein arranged as a lattice of hexagon. The capsid is closed by 7 pentamers at the broad end and 5 at the narrow end of the cone1, 2. Encased in this capsid shell is the viral ribonucleoprotein complex, and together they comprise the core.
Following fusion of the viral membrane with the target cell membrane, the HIV-1 is released into the cytoplasm. The capsid then disassembles releasing free CA in the soluble form3 in a process referred to as uncoating. The intracellular location and timing of HIV-1 uncoating are poorly understood. Single amino-acid substitutions in CA that alter the stability of the capsid also impair the ability of HIV-1 to infect cells4. This indicates that the stability of the capsid is critical for HIV-1 infection.
HIV-1 uncoating has been difficult to study due to lack of availability of sensitive and reliable assays for this process. Here we describe a quantitative method for studying uncoating in vitro using cores isolated from infectious HIV-1 particles. The approach involves isolation of cores by sedimentation of concentrated virions through a layer of detergent and into a linear sucrose gradient, in the cold. To quantify uncoating, the isolated cores are incubated at 37&deg;C for various timed intervals and subsequently pelleted by ultracentrifugation. The extent of uncoating is analyzed by quantifying the fraction of CA in the supernatant. This approach has been employed to analyze effects of viral mutations on HIV-1 capsid stability4, 5, 6. It should also be useful for studying the role of cellular factors in HIV-1 uncoating.

In vitro Uncoating of HIV-1 Cores

Uncoating is an essential step in the early phase of the HIV-1 life cycle and is defined as the disassembly of the capsid shell and the release of the viral ribonucleoprotein complex (vRNP). Here, we demonstrate techniques for isolating intact cores from HIV-1 virions and for quantifying their uncoating in vitro.

Uncoating في المختبر من HIV - 1 النوى

The genome of the retroviruses is encased in a capsid surrounded by a lipid envelope. For lentiviruses, such as HIV-1, the conical capsid shell is ...

Rapid Screening of HIV Reverse Transcriptase and Integrase Inhibitors

Although a number of anti HIV drugs have been approved, there are still problems with toxicity and drug resistance. This demonstrates a need to identify new compounds that can inhibit infection by the common drug resistant HIV-1 strains with minimal toxicity. Here we describe an efficient assay that can be used to rapidly determine the cellular cytotoxicity and efficacy of a compound against WT and mutant viral strains.
The desired target cell line is seeded in a 96-well plate and, after a 24 hr incubation, serially dilutions of the compounds to be tested are added. No further manipulations are necessary for cellular cytotoxicity assays; for anti HIV assays a predetermined amount of either a WT or drug resistant HIV-1 vector that expresses luciferase is added to the cells. Cytotoxicity is measured by using an ATP dependent luminescence assay and the impact of the compounds on infectivity is measured by determining the amount of luciferase in the presence or the absence of the putative inhibitors.
This screening assay takes 4 days to complete and multiple compounds can be screened in parallel. Compounds are screened in triplicate and the data are normalized to the infectivity/ATP levels in absence of target compounds. This technique provides a quick and accurate measurement of the efficacy and toxicity of potential anti HIV compounds.

Here we describe cellular cytotoxicity and single round infectivity assays that allow for the rapid and accurate screening of compounds to determine their cellular cytotoxicity (CC50) and IC50 values against WT and drug resistant HIV-1.

الفحص السريع للفيروس نقص المناعة البشرية والناسخ العكسي مثبطات Integrase

Although a number of anti HIV drugs have been approved, there are still problems with toxicity and drug resistance. This demonstrates a need to identify ...

Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay

HIV-1 envelope glycoproteins (Env) mediate viral entry into target cells and are essential to the infectious cycle. Understanding how those glycoproteins are able to fuel the fusion process through their conformational changes could lead to the design of better, more effective immunogens for vaccine strategies. Here we describe a cell-based ELISA assay that allows studying the recognition of trimeric HIV-1 Env by monoclonal antibodies. Following expression of HIV-1 trimeric Env at the surface of transfected cells, conformation specific anti-Env antibodies are incubated with the cells. A horseradish peroxidase-conjugated secondary antibody and a simple chemiluminescence reaction are then used to detect bound antibodies. This system is highly flexible and can detect Env conformational changes induced by soluble CD4 or cellular proteins. It requires minimal amount of material and no highly-specialized equipment or know-how. Thus, this technique can be established for medium to high throughput screening of antigens and antibodies, such as newly-isolated antibodies.

Understanding viral surface antigens conformations is required to evaluate antibody neutralization and guide the design of effective vaccine immunogens. Here we describe a cell-based ELISA assay that allows the study of the recognition of trimeric HIV-1 Env expressed at the surface of transfected cells by specific anti-Env antibodies.

تقييم بتكوين لHIV-1 مغلف مثلوثي بروتينات سكرية باستخدام خلية القاعدة ELISA الفحص

HIV-1 envelope glycoproteins (Env) mediate viral entry into target cells and are essential to the infectious cycle. Understanding how those glycoproteins ...

Isolation of Exosomes from the Plasma of HIV-1 Positive Individuals

Exosomes are small vesicles ranging in size from 30 nm to 100 nm that are released both constitutively and upon stimulation from a variety of cell types. They are found in a number of biological fluids and are known to carry a variety of proteins, lipids, and nucleic acid molecules. Originally thought to be little more than reservoirs for cellular debris, the roles of exosomes regulating biological processes and in diseases are increasingly appreciated.
Several methods have been described for isolating exosomes from cellular culture media and biological fluids. Due to their small size and low density, differential ultracentrifugation and/or ultrafiltration are the most commonly used techniques for exosome isolation. However, plasma of HIV-1 infected individuals contains both exosomes and HIV viral particles, which are similar in size and density. Thus, efficient separation of exosomes from HIV viral particles in human plasma has been a challenge.
To address this limitation, we developed a procedure modified from Cantin et. al., 2008 for purification of exosomes from HIV particles in human plasma. Iodixanol velocity gradients were used to separate exosomes from HIV-1 particles in the plasma of HIV-1 positive individuals. Virus particles were identified by p24 ELISA. Exosomes were identified on the basis of exosome markers acetylcholinesterase (AChE), and the CD9, CD63, and CD45 antigens. Our gradient procedure yielded exosome preparations free of virus particles. The efficient purification of exosomes from human plasma enabled us to examine the content of plasma-derived exosomes and to investigate their immune modulatory potential and other biological functions.

Techniques describing a gradient procedure to separate exosomes from human immunodeficiency virus (HIV) particles are described. This procedure was used to isolate exosomes away from HIV particles in human plasma from HIV-infected individuals. The isolated exosomes were analyzed for cytokine/chemokine content.

عزل Exosomes من البلازما من HIV-1 الأفراد ايجابية

Exosomes are small vesicles ranging in size from 30 nm to 100 nm that are released both constitutively and upon stimulation from a variety of cell types. ...

Phagosome Migration and Velocity Measured in Live Primary Human Macrophages Infected with HIV-1

Macrophages are phagocytic cells that play a major role at the crossroads between innate and specific immunity. They can be infected by the human immunodeficiency virus (HIV)-1 and because of their resistance to its cytopathic effects they can be considered to be persistent viral reservoirs. In addition, HIV-infected macrophages exhibit defective functions that contribute to the development of opportunistic diseases.
The exact mechanism by which HIV-1 impairs the phagocytic response of macrophages was unknown. We had previously shown that the uptake of various particulate material by macrophages was inhibited when they were infected with HIV-1. This inhibition was only partial and phagosomes did form within HIV-infected macrophages. Therefore, we focused on analyzing the fate of these phagosomes. Phagosome maturation is accompanied by migration of these compartments towards the cell center, where they fuse with lysosomes, generating phagolysosomes, responsible for degradation of the ingested material. We used IgG-opsonized Sheep Red Blood Cells as a target for phagocytosis. To measure the speed of centripetal movement of phagosomes in individual HIV-infected macrophages, we used a combination of bright field and fluorescence confocal microscopy. We established a method to calculate the distance of phagosomes towards the nucleus, and then to calculate the velocity of the phagosomes. HIV-infected cells were identified thanks to a GFP-expressing virus, but the method is applicable to non-infected cells or any type of infection or treatment.

We describe a method to measure the velocity of phagosomes moving towards the cell center in living cells infected with or without the human immunodeficiency virus (HIV) type 1, using spinning disk confocal fluorescence microscopy to identify fluorescent infected cells and bright field microscopy to detect phagosomes.

يبلوع الهجرة والسرعة تقاس في لايف الابتدائية الضامة الإنسان المصابة بفيروس نقص المناعة البشرية-1

Macrophages are phagocytic cells that play a major role at the crossroads between innate and specific immunity. They can be infected by the human ...

Measurement of In Vitro Integration Activity of HIV-1 Preintegration Complexes

HIV-1 envelope proteins engage cognate receptors on the target cell surface, which leads to viral-cell membrane fusion followed by the release of the viral capsid (CA) core into the cytoplasm. Subsequently, the viral Reverse Transcriptase (RT), as part of a namesake nucleoprotein complex termed the Reverse Transcription Complex (RTC), converts the viral single-stranded RNA genome into a double-stranded DNA copy (vDNA). This leads to the biogenesis of another nucleoprotein complex, termed the pre-integration complex (PIC), composed of the vDNA and associated virus proteins and host factors. The PIC-associated viral integrase (IN) orchestrates the integration of the vDNA into the host chromosomal DNA in a temporally and spatially regulated two-step process. First, the IN processes the 3&#39; ends of the vDNA in the cytoplasm and, second, after the PIC traffics to the nucleus, it mediates integration of the processed vDNA into the chromosomal DNA. The PICs isolated from target cells acutely infected with HIV-1 are functional in vitro, as they are competent to integrate the associated vDNA into an exogenously added heterologous target DNA. Such PIC-based in vitro integration assays have significantly contributed to delineating the mechanistic details of retroviral integration and to discovering IN inhibitors. In this report, we elaborate upon an updated HIV-1 PIC assay that employs a nested real-time quantitative Polymerase Chain Reaction (qPCR)-based strategy for measuring the in vitro integration activity of isolated native PICs.

Measurement of In Vitro Integration Activity of HIV-1 Preintegration Complexes

This report describes an in vitro assay for measuring the human immunodeficiency virus type 1 (HIV-1) preintegration complex (PIC)-associated integration activity in the cytoplasmic extracts of acutely infected cells. The integration of PIC-associated HIV-1 DNA into heterologous target DNA is quantified by using a nested real-time polymerase chain reaction strategy.

قياس ل<em&gt; في المختبر</em&gt; التكامل آخر من HIV-1 Preintegration مجمعات

HIV-1 envelope proteins engage cognate receptors on the target cell surface, which leads to viral-cell membrane fusion followed by the release of the ...