C.A.M.F. and L.S. participated in protocol design, acquisition and analysis of data, and drafting of the article. 
The authors wish to thank Dr. Kain, Dr. Loutfy, Dr. Wasmuth, and Dr. Ayi for their contributions.
C.F. was supported by a CTN/Ontario HIV Treatment Network (OHTN) postdoctoral fellowship. L.S. is supported by an OHTN Junior Investigator Development Award. The present work was supported by a Canadian Institutes of Health Research (CIHR) operating grant (MOP-13721 and 115160), and a CIHR New Investigator Catalyst grant.

<ol>
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F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+Plasmodium+falciparum+malaria+on+HIV-1+RNA+blood+plasma+concentration.">The effect of Plasmodium falciparum malaria on HIV-1 RNA blood plasma concentration.</a> AIDS (London, England). 13 (4), 487-494 (1999).</li><li>Kamya, M. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+HIV-1+infection+on+antimalarial+treatment+outcomes+in+Uganda:+a+population-based+study.">Effect of HIV-1 infection on antimalarial treatment outcomes in Uganda: a population-based study.</a> The Journal of infectious diseases. 193 (1), 9-15 (2006).</li><li>Kublin, J. 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M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HIV+infection+deregulates+Tim-3+expression+on+innate+cells:+combination+antiretroviral+therapy+results+in+partial+restoration.">HIV infection deregulates Tim-3 expression on innate cells: combination antiretroviral therapy results in partial restoration.</a> Journal of acquired immune deficiency syndromes. 63 (2), 161-167 (2013).</li><li>Finney, C. A. 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E., et al. <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+inhibits+phagocytosis+and+inflammatory+cytokine+responses+of+human+monocyte-derived+macrophages+to+P.+falciparum+infected+erythrocytes.">HIV-1 inhibits phagocytosis and inflammatory cytokine responses of human monocyte-derived macrophages to P. falciparum infected erythrocytes.</a> PloS one. 7 (2), e32102 (2012).</li><li>Weinberg, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Viability+and+functional+activity+of+cryopreserved+mononuclear+cells.">Viability and functional activity of cryopreserved mononuclear cells.</a> Clinical and diagnostic laboratory immunology. 7 (4), 714-716 (2000).</li><li>Fowke, K. R., Behnke, J., Hanson, C., Shea, K., Cosentino, L. 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The authors have nothing to disclose.

Nuestro protocolo se ha optimizado con el fin de estudiar más realista co-infección por el VIH in vitro de la malaria. En primer lugar, se requiere que los eritrocitos humanos frescos y suero para la cultura parásito de la malaria. Esto es vital para obtener una población saludable de parásitos de la malaria. Lisados ​​de parásitos no pueden ser sustituidos por parásitos vivos como la producción de citoquinas es mucho más rápida e intensa al utilizar P. en vivo falciparum infecta...

Co-infección, la infección con múltiples infecciones concurrentes, es la norma en los ambientes naturales. Co-infección puede tener un impacto importante en la patología de la enfermedad y en el manejo clínico de cada infección. En el contexto de la co-infección, la vacuna y la eficacia del medicamento, así como las pruebas de diagnóstico, puede ser afectado negativamente (revisado en 1). Sin embargo, a pesar de su importancia, la mayoría de las investigaciones de patógenos considera infecciones solamente individuales. La malaria y el VIH-1 (VIH) son las principales causas de morbilidad y mortalidad a nivel mundial. Áreas de la malaria y el VIH endemicidad comparten una amplia superposición geográfica, poniendo a millones de personas en riesgo de coinfección y consecuentemente en riesgo de enfermedad clínica más grave 2-10. Las dos enfermedades interactúan negativamente. En las personas infectadas por el VIH, las cargas virales más altas de VIH y disminuciones temporales en los recuentos de células T CD4 + se puede ver durante una infección de la malaria, mientras quecargas de parásitos de la malaria y el riesgo de malaria clínica y grave son más altos en los individuos coinfectados 2,3,5,7,8,10. Los mecanismos por los que el VIH aumenta la gravedad de la malaria no se entienden completamente y garantiza una mayor investigación. Aquí se describe un método por el cual la malaria y la co-infección con el VIH puede ser estudiado in vitro. En concreto, este método permite el examen de las respuestas inmunitarias donde la malaria es específica en el contexto de la infección por el VIH. Nuestro protocolo describe un sistema versátil co-cultivo utilizando recién aisladas células mononucleares de sangre periférica (PBMCs) aisladas de donantes crónicamente infectados por el VIH in vitro y se cultivaron P. falciparum parasitada eritrocitos (PfRBC). El impacto de la terapia antirretroviral contra el VIH en estas respuestas también puede ser examinada utilizando PBMCs recogidos prospectivamente del VIH (+) donantes antes y después de la terapia. Hemos utilizado este sistema para investigar el impacto de la infección por VIHen la respuesta inmune innata la malaria específico 11,12, y fueron capaces de determinar que IFN y TNF respuestas donde la malaria es específica se deterioran en las células NK, células NKT, delta gamma células T de VIH (+) donantes pre y post tratamiento antirretroviral del VIH . Además, hemos sido capaces de utilizar este sistema para determinar que las funciones de monocitos también se vean afectados en donantes VIH (+), pero se recuperan después de VIH el tratamiento antirretroviral.

<table><tbody><tr><td>alanine</td><td>Sigma</td><td>A7377</td><td></td></tr><tr><td>antibodies (see other table)</td><td></td><td></td><td></td></tr><tr><td>BD Cytofix/Cytoperm with BD GolgiPlug</td><td>BD</td><td>555028</td><td>includes brefeldin A, cytofix/cytoperm buffer and perm/wash buffer</td></tr><tr><td>BD Vacutainer ACD Solution A</td><td>BD</td><td>364506</td><td></td></tr><tr><td>BD Vacutainer Sodium Heparin</td><td>BD</td><td>17-1440-02</td><td></td></tr><tr><td>DPBS (no calcium, no magnesium)</td><td>Corning</td><td>21-031-CV</td><td></td></tr><tr><td>Fetal Bovine Serum</td><td>Sigma</td><td>F1051</td><td>heat inactivate before use</td></tr><tr><td>Ficoll-Paque PLUS</td><td>GE Healthcare</td><td>17-1440-02</td><td></td></tr><tr><td>gentamycin (10 mg/ml)</td><td>Gibco</td><td>15710-064</td><td></td></tr><tr><td>Hema3 Staining Set</td><td>Fisher</td><td>122-911</td><td></td></tr><tr><td>HEPES</td><td>Fisher</td><td>BP310-500</td><td></td></tr><tr><td>hypoxanthine</td><td>Sigma</td><td>H9636</td><td></td></tr><tr><td>Ionomycin</td><td>Sigma</td><td>I3909</td><td></td></tr><tr><td>MEM non-essential amino acids (10 mM)</td><td>Gibco</td><td>11140</td><td></td></tr><tr><td>PMA</td><td>Sigma</td><td>P8139</td><td></td></tr><tr><td>RPMI-1640 powder</td><td>Life-Technologies</td><td>31800-022</td><td></td></tr><tr><td>RPMI-1640 with L-glutamine and HEPES</td><td>Thermo Scientific</td><td>SH30255.01</td><td></td></tr><tr><td>sodium bicarbonate (powder, cell culture)</td><td>Sigma</td><td>S5761</td><td></td></tr><tr><td>Sodium Pyruvate (100 mM)</td><td>Gibco</td><td>11360</td><td></td></tr><tr><td>Tris (Trizma base)</td><td>Sigma</td><td>T6066</td><td></td></tr><tr><td>Trizol</td><td>Ambion</td><td>15596018</td><td></td></tr><tr><td>Trypan Blue (0.4%)</td><td>Gibco</td><td>15250-061</td><td></td></tr><tr><td>BD CompBead</td><td>BD</td><td>552843, 552845</td><td>depends on antibodies used</td></tr><tr><td>Parasite Gas Mixture</td><td>By special order</td><td></td><td>3% CO&lt;sub&gt;2&lt;/sub&gt;, 1% O&lt;sub&gt;2&lt;/sub&gt;, balance N&lt;sub&gt;2&lt;/sub&gt;</td></tr><tr><td>&lt;strong&gt;Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>0.2 &amp;#956;m filter unit</td><td></td><td></td><td></td></tr><tr><td>Glass slides</td><td></td><td></td><td></td></tr><tr><td>T25 flasks</td><td></td><td></td><td></td></tr><tr><td>T75 flasks</td><td></td><td></td><td></td></tr><tr><td>50 ml tubes</td><td></td><td></td><td></td></tr><tr><td>24 well culture plates</td><td></td><td></td><td></td></tr><tr><td>unplugged Pasteur pipettes</td><td></td><td></td><td></td></tr><tr><td>plugged Pasteur pipettes</td><td></td><td></td><td></td></tr><tr><td>sterile transfer pipettes</td><td></td><td></td><td></td></tr><tr><td>hemocytometer</td><td></td><td></td><td></td></tr><tr><td>flow cytometer (3 laser)</td><td></td><td></td><td></td></tr><tr><td>&lt;strong&gt;Antibodies used for flow cytometry&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Anti-TNF</td><td>eBiosciences</td><td>551487</td><td>FITC (fluorophore)
2 &amp;#956;l</td></tr><tr><td>Anti-IFN&amp;#947;</td><td>Biolegend</td><td>506507</td><td>PE (fluorophore) 
20 &amp;#956;l</td></tr><tr><td>Anti-CD8</td><td>Biolegend</td><td>300914</td><td>PE-Cy7 (fluorophore) 
1 &amp;#956;l</td></tr><tr><td>Anti-CD14</td><td>Biolegend; BD Biosciences</td><td>325624; 551487</td><td>Biotin (fluorophore) 
0.5 &amp;#956;l
Streptavin PE-TR (fluorophore) 
0.1 &amp;#956;l</td></tr><tr><td>Anti-CD56</td><td>Biolegend</td><td>318322</td><td>PerCP/Cy5.5 (fluorophore) 
5 &amp;#956;l</td></tr><tr><td>Anti-&amp;#947;&amp;#948;</td><td>Biolegend</td><td>331212</td><td>APC (fluorophore)
5 &amp;#956;l</td></tr><tr><td>Anti-CD3</td><td>Biolegend</td><td>300426</td><td>APC-Cy7 (fluorophore) 
5 &amp;#956;l</td></tr><tr><td>Anti-CD4</td><td>Biolegend</td><td>317424</td><td>Pacific Blue (fluorophore)
1 &amp;#956;l</td></tr></tbody></table>

an in vitro model for measuring immune responses to malaria in the context of hiv co-infection

Malaria and HIV co-infection is a growing health priority. However, most research on malaria or HIV currently focuses on each infection individually. Although understanding the disease dynamics for each of these pathogens independently is vital, it is also important that the interactions between these pathogens are investigated and understood. 
We have developed a versatile in vitro model of HIV-malaria co-infection to study host immune responses to malaria in the context of HIV infection. Our model allows the study of secreted factors in cellular supernatants, cell surface and intracellular protein markers, as well as RNA expression levels. The experimental design and methods used limit variability and promote data reliability and reproducibility. 
All pathogens used in this model are natural human pathogens (Plasmodium falciparum and HIV-1), and all infected cells are naturally infected and used fresh. We use human erythrocytes parasitized with P. falciparum and maintained in continuous in vitro culture. We obtain freshly isolated peripheral blood mononuclear cells from chronically HIV-infected volunteers. Every condition used has an appropriate control (P. falciparum parasitized vs. normal erythrocytes), and every HIV-infected donor has an HIV uninfected control, from which cells are harvested on the same day. This model provides a realistic environment to study the interactions between malaria parasites and human immune cells in the context of HIV infection.

Los gráficos representan los niveles de producción de IFN a partir de células NKT (Figura 2), utilizando CD56 + CD3 + γδ- puertas para obtener la población las células NKT (datos no mostrados). Las células se cultivaron durante 72 horas antes de la tinción. Una vez teñidos, 100.000 células CD3 + fueron adquiridas en el citómetro de flujo para obtener grandes poblaciones suficientes de NK, NKT y las células delta gamma (células de interés). Un mínimo de 5.600 células NKT se muestran en c...

Watch this Scientific Journal Video about An In Vitro Model for Measuring Immune Responses to Malaria in the Context of HIV Co-infection at JoVE.com

An In Vitro Model for Measuring Immune Responses to Malaria in the Context of HIV Co-infection

Human co-infection is difficult to replicate in vitro. However, human malaria parasites can readily be cultured in vitro, as can freshly isolated human peripheral blood mononuclear cells naturally infected with HIV. This provides an excellent model for studying early immune responses to malaria parasites in the context of HIV co-infection.

Un<em&gt; In Vitro</em&gt; Modelo para medir la respuesta inmune a la malaria en el contexto del VIH Co-infección

Malaria and HIV co-infection is a growing health priority. However, most research on malaria or HIV currently focuses on each infection individually. ...

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Immunology and Infection

An In Vitro Model for Measuring Immune Responses to Malaria in the Context of HIV Co-infection

10.2K vistas.  University of Calgary. Human co-infection is difficult to replicate in vitro. However, human malaria parasites can readily be cultured in vitro, as can freshly isolated human peripheral blood mononuclear cells naturally infected with HIV. This provides an excellent model for studying early immune responses to malaria parasites in the context of HIV co-infection. 

Video: An In Vitro Model for Measuring Immune Responses to Malaria in the Context of HIV Co-infection

An In vitro Co-infection Model to Study Plasmodium falciparum-HIV-1 Interactions in Human Primary Monocyte-derived Immune Cells

Plasmodium falciparum, the causative agent of the deadliest form of malaria, and human immunodeficiency virus type-1 (HIV-1) are among the most important health problems worldwide, being responsible for a total of 4 million deaths annually1. Due to their extensive overlap in developing regions, especially Sub-Saharan Africa, co-infections with malaria and HIV-1 are common, but the interplay between the two diseases is poorly understood. Epidemiological reports have suggested that malarial infection transiently enhances HIV-1 replication and increases HIV-1 viral load in co-infected individuals2,3. Because this viremia stays high for several weeks after treatment with antimalarials, this phenomenon could have an impact on disease progression and transmission.
The cellular immunological mechanisms behind these observations have been studied only scarcely. The few in vitro studies investigating the impact of malaria on HIV-1 have demonstrated that exposure to soluble malarial antigens can increase HIV-1 infection and reactivation in immune cells. However, these studies used whole cell extracts of P. falciparum schizont stage parasites and peripheral blood mononuclear cells (PBMC), making it hard to decipher which malarial component(s) was responsible for the observed effects and what the target host cells were4,5. Recent work has demonstrated that exposure of immature monocyte-derived dendritic cells to the malarial pigment hemozoin increased their ability to transfer HIV-1 to CD4+ T cells6,7, but that it decreased HIV-1 infection of macrophages8. To shed light on this complex process, a systematic analysis of the interactions between the malaria parasite and HIV-1 in different relevant human primary cell populations is critically needed.
Several techniques for investigating the impact of HIV-1 on the phagocytosis of micro-organisms and the effect of such pathogens on HIV-1 replication have been described. We here present a method to investigate the effects of P. falciparum-infected erythrocytes on the replication of HIV-1 in human primary monocyte-derived macrophages. The impact of parasite exposure on HIV-1 transcriptional/translational events is monitored by using single cycle pseudotyped viruses in which a luciferase reporter gene has replaced the Env gene while the effect on the quantity of virus released by the infected macrophages is determined by measuring the HIV-1 capsid protein p24 by ELISA in cell supernatants.

An In vitro Co-infection Model to Study Plasmodium falciparum-HIV-1 Interactions in Human Primary Monocyte-derived Immune Cells

We have developed an in vitro malaria-HIV-1 co-infection model to study the impact of Plasmodium falciparum on the HIV-1 replicative cycle in human primary monocyte-derived macrophages. This versatile system can easily be adapted to other primary cell types susceptible to HIV-1 infection.

Un<em&gt; In vitro</em&gt; Co-infección modelo para estudiar<em&gt; Plasmodium falciparum</em&gt;-VIH-1 en las interacciones humano primario de monocitos derivados de las células inmunitarias

Plasmodium falciparum, the causative agent  of the deadliest form of malaria, and human immunodeficiency virus type-1 (HIV-1) are among the most important ...

Investigación

Inmunología e Infección

In Vitro Assay to Evaluate the Impact of Immunoregulatory Pathways on HIV-specific CD4 T Cell Effector Function

T cell exhaustion is a major factor in failed pathogen clearance during chronic viral infections. Immunoregulatory pathways, such as PD-1 and IL-10, are upregulated upon this ongoing antigen exposure and contribute to loss of proliferation, reduced cytolytic function, and impaired cytokine production by CD4 and CD8 T cells. In the murine model of LCMV infection, administration of blocking antibodies against these two pathways augmented T cell responses. However, there is currently no in vitro assay to measure the impact of such blockade on cytokine secretion in cells from human samples. Our protocol and experimental approach enable us to accurately and efficiently quantify the restoration of cytokine production by HIV-specific CD4 T cells from HIV infected subjects.
Here, we depict an in vitro experimental design that enables measurements of cytokine secretion by HIV-specific CD4 T cells and their impact on other cell subsets. CD8 T cells were depleted from whole blood and remaining PBMCs were isolated via Ficoll separation method. CD8-depleted PBMCs were then incubated with blocking antibodies against PD-L1 and/or IL-10R&#945; and, after stimulation with an HIV-1 Gag peptide pool, cells were incubated at 37 &#176;C, 5% CO2. After 48 hr, supernatant was collected for cytokine analysis by beads arrays and cell pellets were collected for either phenotypic analysis using flow cytometry or transcriptional analysis using qRT-PCR. For more detailed analysis, different cell populations were obtained by selective subset depletion from PBMCs or by sorting using flow cytometry before being assessed in the same assays. These methods provide a highly sensitive and specific approach to determine the modulation of cytokine production by antigen-specific T-helper cells and to determine functional interactions between different populations of immune cells.

In Vitro Assay to Evaluate the Impact of Immunoregulatory Pathways on HIV-specific CD4 T Cell Effector Function

We developed an in vitro assay to investigate the role of immunoregulatory pathways in the regulation of cytokine secretion by HIV-specific CD4 T cells.

Ensayo in vitro para evaluar el impacto de inmunoreguladoras Caminos de CD4 T función específica para el VIH efector celular

T cell exhaustion is a major factor in failed pathogen clearance during chronic viral infections. Immunoregulatory pathways, such as PD-1 and IL-10, are ...

An Experimental Model to Study Tuberculosis-Malaria Coinfection upon Natural Transmission of Mycobacterium tuberculosis and Plasmodium berghei

Coinfections naturally occur due to the geographic overlap of distinct types of pathogenic organisms. Concurrent infections most likely modulate the respective immune response to each single pathogen and may thereby affect pathogenesis and disease outcome. Coinfected patients may also respond differentially to anti-infective interventions. Coinfection between tuberculosis as caused by mycobacteria and the malaria parasite Plasmodium, both of which are coendemic in many parts of sub-Saharan Africa, has not been studied in detail. In order to approach the challenging but scientifically and clinically highly relevant question how malaria-tuberculosis coinfection modulate host immunity and the course of each disease, we established an experimental mouse model that allows us to dissect the elicited immune responses to both pathogens in the coinfected host. Of note, in order to most precisely mimic naturally acquired human infections, we perform experimental infections of mice with both pathogens by their natural routes of infection, i.e. aerosol and mosquito bite, respectively.

An Experimental Model to Study Tuberculosis-Malaria Coinfection upon Natural Transmission of Mycobacterium tuberculosis and Plasmodium berghei

Tuberculosis and malaria are two of the most prevalent infections in humans and major causes of morbidity and mortality in impoverished populations in the tropics. We established an experimental model system to study outcome of malaria-tuberculosis coinfection in mice after challenge with both pathogens via their natural route of infection.

Un modelo experimental para estudiar la tuberculosis-Malaria Coinfección sobre Transmisión Natural de Mycobacterium tuberculosis Y Plasmodium berghei</i

Coinfections naturally occur due to the geographic overlap of distinct types of pathogenic organisms. Concurrent infections most likely modulate the ...

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.

HIV-1 innate sensing requires direct contact of infected CD4+ T cells with plasmacytoid dendritic cells (pDCs). In order to study this process, the protocols described here use freshly isolated human peripheral blood mononuclear cells (PBMCs) or plasmacytoid dendritic cells (pDCs) to sense infections in either T cell line (MT4) or heterologous primary CD4+ T cells. In order to ensure proper sensing, it is essential that PBMC are isolated immediately after blood collection and that optimal percentage of infected T cells are used. Furthermore, multi-parametric flow cytometric staining can be used to confirm that PBMC samples contain the different cell lineages at physiological ratios. A number of controls can also be included to evaluate viability and functionality of pDCs. These include, the presence of specific surface markers, assessing cellular responses to known agonist of Toll-Like Receptors (TLR) pathways, and confirming a lack of spontaneous type-I interferon (IFN) production. In this system, freshly isolated PBMCs or pDCs are co-cultured with HIV-1 infected cells in 96 well plates for 18-22 hr. Supernatants from these co-cultures are then used to determine the levels of bioactive type-I IFNs by monitoring the activation of the ISGF3 pathway in HEK-Blue IFN-&#945;/&#946; cells. Prior and during co-culture conditions, target cells can be subjected to flow cytometric analysis to determine a number of parameters, including the percentage of infected cells, levels of specific surface markers, and differential killing of infected cells. Although, these protocols were initially developed to follow type-I IFN production, they could potentially be used to study other imuno-modulatory molecules released from pDCs and to gain further insight into the molecular mechanisms governing HIV-1 innate sensing.

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.

Unlike cell-free HIV-1 particles, infected CD4+ T cells are effectively sensed by plasmacytoid dendritic cells (pDCs). This manuscript describes a method where peripheral blood mononuclear cells (PBMCs) or isolated pDCs are co-cultured with HIV-1 infected T cells to evaluate innate sensing by pDCs as assessed by release of type-I IFN.

La evaluación de la innata de detección de VIH-1 CD4 infectados<sup&gt; +</sup&gt; Células T por las células dendríticas plasmocitoides Usando un<em&gt; Ex vivo</em&gt; Co-cultura del sistema.

HIV-1 innate sensing requires direct contact of infected CD4+ T cells with plasmacytoid dendritic cells (pDCs). In order to study this process, the ...

In Vivo Assessment of Rodent Plasmodium Parasitemia and Merozoite Invasion by Flow Cytometry

During blood stage infection, malaria parasites invade, mature, and replicate within red blood cells (RBCs). This results in a regular growth cycle and an exponential increase in the proportion of malaria infected RBCs, known as parasitemia. We describe a flow cytometry based protocol which utilizes a combination of the DNA dye Hoechst, and the mitochondrial membrane potential dye, JC-1, to identify RBCs which contain parasites and therefore the parasitemia, of in vivo blood samples from Plasmodium chabaudi adami DS infected mice. Using this approach, in combination with fluorescently conjugated antibodies, parasitized RBCs can be distinguished from leukocytes, RBC progenitors, and RBCs containing Howell-Jolly bodies (HJ-RBCs), with a limit of detection of 0.007% parasitemia. Additionally, we outline a method for the comparative assessment of merozoite invasion into two different RBC populations. In this assay RBCs, labeled with two distinct compounds identifiable by flow cytometry, are transfused into infected mice. The relative rate of invasion into the two populations can then be assessed by flow cytometry based on the proportion of parasitized RBCs in each population over time. This combined approach allows the accurate measurement of both parasitemia and merozoite invasion in an in vivo model of malaria infection.

In Vivo Assessment of Rodent Plasmodium Parasitemia and Merozoite Invasion by Flow Cytometry

The malaria parasite invades and replicates within red blood cells. The accurate assessment of merozoite invasion and parasitemia is therefore crucial in assessing the course of malaria infection. Here we describe a flow cytometry based protocol for the measurement of these parameters in a mouse model of malaria.

En la Evaluación in vivo de roedores Plasmodium parasitemia y Merozoite Invasión por Citometría de Flujo

During blood stage infection, malaria parasites invade, mature, and replicate within red blood cells (RBCs). This results in a regular growth cycle and an ...

Stem-cell Based Engineered Immunity Against HIV Infection in the Humanized Mouse Model

With the rapid development of stem cell-based gene therapies against HIV, there is pressing requirement for an animal model to study the hematopoietic differentiation and immune function of the genetically modified cells. The humanized Bone-marrow/Liver/Thymus (BLT) mouse model allows for full reconstitution of a human immune system in the periphery, which includes T cells, B cells, NK cells and monocytes. The human thymic implant also allows for thymic selection of T cells in autologous thymic tissue. In addition to the study of HIV infection, the model stands as a powerful tool to study differentiation, development and functionality of cells derived from hematopoietic stem cells (HSCs). Here we outline the construction of humanized non-obese diabetic (NOD)-severe combined immunodeficient (SCID)-common gamma chain knockout (c&#947;-/-)-Bone-marrow/Liver/Thymus (NSG-BLT) mice with HSCs transduced with CD4 chimeric antigen receptor (CD4CAR) lentivirus vector. We show that the CD4CAR HSCs can successfully differentiate into multiple lineages and have anti-HIV activity. The goal of the study is to demonstrate the use of NSG-BLT mouse model as an in vivo model for engineered immunity against HIV. It is worth noting that, because lentivirus and human tissue is used, experiments and surgeries should be performed in a Class II biosafety cabinet in a Biosafety Level 2 (BSL2) with special precautions (BSL2+) facility.

This protocol describes the methods in constructing a humanized bone-marrow/liver/thymus mouse model with stem cell-based engineered immunity against HIV infection.

-Base de células madre Inmunidad Diseñado frente a la infección por VIH en el modelo de ratón humanizado

With the rapid development of stem cell-based gene therapies against HIV, there is pressing requirement for an animal model to study the hematopoietic ...

Medicina

Establishment of the Dual Humanized TK-NOG Mouse Model for HIV-associated Liver Pathogenesis

Despite the increased life expectancy of patients infected with human immunodeficiency virus-1 (HIV-1), liver disease has emerged as a common cause of their morbidity. The liver immunopathology caused by HIV-1 remains elusive. Small xenograft animal models with human hepatocytes and human immune system can recapitulate the human biology of the disease&#39;s pathogenesis. Herein, a protocol is described to establish a dual humanized mouse model through human hepatocytes and CD34+ hematopoietic stem/progenitor cells (HSPCs) transplantation, to study liver immunopathology as observed in HIV-infected patients. To achieve dual reconstitution, male TK-NOG (NOD.Cg-Prkdcscid Il2rgtm1Sug Tg(Alb-TK)7-2/ShiJic) mice are intraperitoneally injected with ganciclovir (GCV) doses to eliminate mouse transgenic liver cells, and with treosulfan for nonmyeloablative conditioning, both of which facilitate human hepatocyte (HEP) engraftment and human immune system (HIS) development. Human albumin (ALB) levels are evaluated for liver engraftment, and the presence of human immune cells in blood detected by flow cytometry confirms the establishment of human immune system. The model developed using the protocol described here resembles multiple components of liver damage from HIV-1 infection. Its establishment could prove to be essential for studies of hepatitis virus co-infection and for the evaluation of antiviral and antiretroviral drugs.

This protocol provides a reliable method to establish humanized mice with both human immune system and liver cells. Dual reconstituted immunodeficient mice achieved via intrasplenic injection of human hepatocytes and CD34+ hematopoietic stem cells are susceptible to human immunodeficiency virus-1 infection and recapitulate liver damage as observed in HIV-infected patients.

Establecimiento del modelo de ratón TK-NOG humanizado dual para la patogénesis hepática asociada al VIH

Despite the increased life expectancy of patients infected with human immunodeficiency virus-1 (HIV-1), liver disease has emerged as a common cause of ...

Measuring Naturally Acquired Phagocytosis-Inducing Antibodies to Plasmodium falciparum Parasites by a Flow Cytometry-Based Assay

The protocol describes how to set up and run a flow cytometry-based phagocytosis assay of Plasmodium falciparum-infected erythrocytes (IEs) opsonized by naturally acquired IgG antibodies specific for VAR2CSA. VAR2CSA is the parasite antigen that mediates the selective sequestration of IEs in the placenta that can cause a severe form of malaria in pregnant women, called placental malaria (PM). Protection from PM is mediated by VAR2CSA-specific antibodies that are believed to function by inhibiting placental sequestration and/or by opsonizing IEs for phagocytosis. The assay employs late-stage-synchronized IEs that have been selected in vitro to express VAR2CSA, plasma/serum-antibodies from women with naturally acquired PM-specific immunity, and the phagocytic cell line THP-1. However, the protocol can easily be modified to assay the functionality of antibodies to any parasite antigen present on the IE surface, whether induced by natural exposure or by vaccination. The assay offers simple and high-throughput evaluation, with good reproducibility, of an important functional aspect of antibody-mediated immunity in malaria. It is, therefore, useful when evaluating clinical immunity to P. falciparum malaria, a major cause of morbidity and mortality in the tropics, particularly in sub-Saharan Africa.

Measuring Naturally Acquired Phagocytosis-Inducing Antibodies to Plasmodium falciparum Parasites by a Flow Cytometry-Based Assay

The overall goal of this protocol is to provide instruction on how to measure the capacity of antibodies present in sera or plasma of individuals, naturally exposed to Plasmodium falciparum infection, to opsonize and induce phagocytosis of the parasite-infected erythrocytes (IEs).

Medición de anticuerpos que inducen la fagocitosis adquirida naturalmente a los parásitos plasmodium falciparum mediante un ensayo basado en citometría de flujo

The protocol describes how to set up and run a flow cytometry-based phagocytosis assay of Plasmodium falciparum-infected erythrocytes (IEs) opsonized by ...

In Vitro Assay of Plasmodium-Infected Red Blood Cell Killing by Cytotoxic Lymphocytes

Malaria is a major public health concern, presenting more than 200 million cases per year worldwide. Despite years of scientific efforts, protective immunity to malaria is still poorly understood, mainly due to methodological limitations of long-term Plasmodium culture, especially for Plasmodium vivax. Most studies have focused on adaptive immunity protection against malaria by antibodies, which play a key role in controlling malaria. However, the sterile protection induced by attenuated Plasmodium sporozoites vaccines is related to cellular response, mainly to cytotoxic T lymphocytes, such as CD8+ and gamma delta T cells (&#947;&#948; T). Hence, new methodologies must be developed to better comprehend the functions of the cellular immune response and thus support future therapy and vaccine development. To find a new strategy to analyze this cell-mediated immunity to Plasmodium blood-stage infection, our group established an in vitro assay that measures infected red blood cell (iRBC) killing by cytotoxic lymphocytes. This assay can be used to study cellular immune response mechanisms against different Plasmodium spp. in the blood stage. Innate and adaptative cytotoxic immune cells can directly eliminate iRBCs and the intracellular parasite in an effector:target mechanism. Target iRBCs are labeled to evaluate cell viability, and cocultured with effector cells (CD8+ T, &#947;&#948; T, NK cells, etc.). The lysis percentage is calculated based on tested conditions, compared to a spontaneous lysis control in a flow cytometry-based assay. Ultimately, this killing assay methodology is a major advance in understanding cell-mediated immunity to blood-stage malaria, helping uncover new potential therapeutic targets and accelerate the development of malaria vaccines.

In Vitro Assay of Plasmodium-Infected Red Blood Cell Killing by Cytotoxic Lymphocytes

Here we describe a new method to help elucidate the mechanisms of cellular immunity to Plasmodium during the blood stage of infection. This is an in vitro assay that measures infected red blood cell killing by cytotoxic lymphocytes.&#160;

In vitro Ensayo de destrucción de glóbulos rojos infectados con plasmodio por linfocitos citotóxicos

Malaria is a major public health concern, presenting more than 200 million cases per year worldwide. Despite years of scientific efforts, protective ...

Generation of an In Vitro Cell Culture Model of Malaria-HIV Co-Infection

Source: Finney, C. et al., <a href="https://app.jove.com/v/52969">An In Vitro&#160;Model for Measuring Immune Responses to Malaria in the Context of HIV Co-infection.</a>&#160;J. Vis. Exp.&#160;(2015)
This video demonstrates the generation of an in vitro malaria-HIV co-infection cell culture model. HIV-infected peripheral blood mononuclear cells co-cultured with Plasmodium falciparum parasitized erythrocytes potentially support each other&#39;s growth and provide insights into the immune responses and disease progression in HIV and malaria co-infections.

Generación de un modelo de cultivo celular in vitro de coinfección malaria-VIH

All procedures involving sample collection have been performed in accordance with the institute&#39;s IRB guidelines.
CAUTION: Working with human blood ...

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