Name: a simple flow cytometric method to measure glucose uptake and glucose transporter expression for monocyte subpopulations in whole blood
Uploaded: 2016-08-12T14:00:00
Description: Watch this Scientific Journal Video about A Simple Flow Cytometric Method to Measure Glucose Uptake and Glucose Transporter Expression for Monocyte Subpopulations in Whole Blood at JoVE.com

This research was funded by the Australian Centre for HIV and Hepatitis Virology Research (ACH2) and a 2010 developmental grant (CNIHR) from the University of Washington Center for AIDS Research (CFAR), an NIH funded program under award number AI027757 which is supported by the following NIH Institutes and Centers (NIAID, NCI, NIMH, NIDA, NICHD, NHLBI, NIA). C.S.P is a recipient of the CNIHR and ACH2 grant. SMC is a recipient of a National Health and Medical Research Council of Australia (NHMRC) Principal Research Fellowship. The authors gratefully acknowledge the contribution to this work of the Victorian Operational Infrastructure Support Program received by the Burnet Institute. We acknowledge the assistance of Geza Paukovic and Eva Orlowski-Oliver from the AMREP Flow Cytometry Core Facility for flow cytometry training and technical advice. We thank Angus Morgan for media coaching and organization of the video shoot.&#160; Our gratitude to Jesse Masson and Jehad Abdulaziz K. Alzahrani for lab assistance during the video shoot.&#160;We thank the efforts of Dr David Simar at the School of Medical Sciences, UNSW, Australia who offered critical methodological advice. C.S.P would like to thank <a href="http://www.nice-consultants.com/">www.nice-consultants.com</a> for graphic consultations.
AUTHORS&#39; CONTRIBUTION:
C.S.P conceived the project, designed and conducted experiments, analyzed and interpreted data, and wrote the manuscript. J.J.A interpreted data and wrote the manuscript. T.R.B wrote the manuscript. J.M.M interpreted data, made critical intellectual suggestions, and reviewed the manuscript. S.M.C interpreted data, made critical intellectual suggestions and reviewed the manuscript.

NOTE: HIV-infected and HIV-uninfected subjects were recruited from the Infectious Diseases Unit at The Alfred Hospital in Melbourne, VIC, Australia, and from the local community, respectively. Informed consent was obtained from all participants, and the research was approved by The Alfred Hospital Research and Ethics Committee.
1. Glut1 Cell Surface Detection on Monocytes and Monocyte Subpopulations
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	<li>Collect blood in citrate ACD-B anticoagulant tubes and begin the experiments in a b...

<ol>
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The protocol described here details a simple method to examine glucose transporter expression and fluorescent glucose analog uptake by monocyte and monocyte subpopulations in whole blood. By assessing 2-NBDG uptake in whole blood, this technique allows for conditions similar to those in vivo. A previous study examined 6-NBDG uptake in monocytes separated from whole blood by density centrifugation17. However, this study did not examine monocyte subpopulations and separation of monocytes from whole bloo...

Monocytes are a major component of the human innate immune system that are rapidly mobilized to sites of infection and inflammation1. Activation of monocytes is critical for limiting acute damage by pathogens and is also central to the pathogenesis of several chronic diseases, including atherosclerosis2, cancer3, and HIV4,5.
The metabolism of resting and activated monocytes differs dramatically, with resting monocytes utilizing oxidative metabolism and activated monocytes utilizing glycolytic metabolism (i.e., fermentation of glucose to lactate)6. Activation of monocytes induces expression of glucose transporters that allows for increased glucose uptake for glycolytic metabolism7. Monocyte glucose transporter 1 (Glut1) is one such transporter upregulated during activation and its expression has been shown to lead to production of pro-inflammatory cytokines in vitro and in adipose tissue of obese mice8. Infection of a monocytic cell line by Kaposi sarcoma associated herpesvirus leads to cellular upregulation of Glut19, and we recently showed that during chronic HIV infection an increased percentage of Glut1-expressing monocytes are present during untreated and combination antiretroviral therapy-treated infection10. Taken together, these studies show that glucose uptake and glycolytic metabolism by monocytes are important aspects of many inflammatory diseases. Thus, a simple method to measure monocyte Glut1 expression and glucose uptake during homeostasis and inflammatory disease is likely to be of use to a wide range of researchers.
Human monocytes are heterogeneous, being comprised of three distinct subsets that can be examined by differential expression of the cell surface markers CD14 and CD1611,12. Classical monocytes express a high level of CD14 but do not express CD16 (CD14++CD16-), intermediate monocytes express a high level of CD14 and an intermediate level of CD16 (CD14++CD16+), and non-classical monocytes express a low level of CD14 and a high level of CD16 (CD14+CD16++). Monocytes that express CD16 are termed CD16+ monocytes, which compared to CD16- monocytes have high expression of inflammatory cytokines and the ability to more effectively present antigens13,14. Approximately 10% of monocytes express CD16 during homeostasis with higher percentages observed during inflammation15. Monocyte subpopulations are associated with certain disease states and could be useful biological markers of disease and disease progression16.
Our goal was to identify a method that can measure glucose transporter expression and glucose uptake by human monocytes and monocyte subpopulations in conditions as close to physiological conditions as possible. Previous studies measured monocyte glucose transporter expression and glucose uptake17,18, though these methods examined isolated monocytes that can have altered protein expression compared to physiological conditions19, and no previous study has examined human monocyte subpopulations. Using multi-parametric flow cytometry, we describe a method to examine glucose transporter expression and uptake of the fluorescent glucose analog 2-NBDG by total monocytes and monocyte subpopulations (based on CD14 and CD16 expression) within whole unmanipulated blood.

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			<td height="61" style="height:61px;width:140px;">VACUETT Tube 9 ml ACD-B anticoagulant tubes</td>
			<td style="width:147px;">Greiner Bio-One GmbH</td>
			<td style="width:139px;">455094</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:140px;">5 ml sterile polypropylene tubes</td>
			<td style="width:147px;">BD Biosciences</td>
			<td style="width:139px;">352063</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:140px;">Albumin from Bovine Serum (BSA)</td>
			<td style="width:147px;">Sigma-Aldrich</td>
			<td style="width:139px;">A7906</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:140px;">16% formaldehyde solution</td>
			<td style="width:147px;">Electron Microscopy Science</td>
			<td style="width:139px;">15710</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="121">
			<td height="121" style="height:121px;width:140px;">BD FACS lysing solution (10X)</td>
			<td style="width:147px;">BD Biosciences</td>
			<td style="width:139px;">349202</td>
			<td style="width:147px;">Dilute BD FACS lysing solution 1/10 with deionized water for working concentration (store for up to 1 week at 4&#176;C)</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:140px;">anti-CD3-PE</td>
			<td style="width:147px;">BD Biosciences</td>
			<td style="width:139px;">555340</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:140px;">anti CD14-APC</td>
			<td style="width:147px;">BD Biosciences</td>
			<td style="width:139px;">555399</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:140px;">anti-CD16-PECy7</td>
			<td style="width:147px;">BD Biosciences</td>
			<td style="width:139px;">557744</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:140px;">anti-Glut1-FITC</td>
			<td style="width:147px;">R &#38; D Systems</td>
			<td style="width:139px;">FAB1418F</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:140px;">IgG2b-FITC</td>
			<td style="width:147px;">R &#38; D Systems</td>
			<td style="width:139px;">IC0041F</td>
			<td style="width:147px;"></td>
		</tr>
		<tr height="241">
			<td height="241" style="height:241px;width:140px;">2-NBDG</td>
			<td style="width:147px;">Life technologies</td>
			<td style="width:139px;">N13195</td>
			<td style="width:147px;">Suspend 5 mg of 2-NBDG into 1 ml of deionized water to make a 14.60 mM stock solution (keep for up to 6 months at 4&#176;C). To make the working 2-NBDG concentration, dilute stock 1/100 with 1X DPBS. Cover with foil. (store for up to 1 week at 4&#176;C)</td>
		</tr>
		<tr height="77">
			<td height="77" style="height:78px;width:140px;">Dulbecco&#8217;s Phosphate Buffered Saline (1X)</td>
			<td style="width:147px;">Life technologies</td>
			<td style="width:139px;">14190-144</td>
			<td style="width:147px;">To make wash solution, add 0.5 g BSA per 100 ml DPBS (store for up to 2 weeks at 4&#176;C)</td>
		</tr>
	</tbody>
</table>

a simple flow cytometric method to measure glucose uptake and glucose transporter expression for monocyte subpopulations in whole blood

Monocytes are innate immune cells that can be activated by pathogens and inflammation associated with certain chronic inflammatory diseases. Activation of monocytes induces effector functions and a concomitant shift from oxidative to glycolytic metabolism that is accompanied by increased glucose transporter expression. This increased glycolytic metabolism is also observed for trained immunity of monocytes, a form of innate immunological memory. Although in vitro protocols examining glucose transporter expression and glucose uptake by monocytes have been described, none have been examined by multi-parametric flow cytometry in whole blood. We describe a multi-parametric flow cytometric protocol for the measurement of fluorescent glucose analog 2-NBDG uptake in whole blood by total monocytes and the classical (CD14++CD16-), intermediate (CD14++CD16+) and non-classical (CD14+CD16++) monocyte subpopulations. This method can be used to examine glucose transporter expression and glucose uptake for total monocytes and monocyte subpopulations during homeostasis and inflammatory disease, and can be easily modified to examine glucose uptake for other leukocytes and leukocyte subpopulations within blood.

Compensation must be performed for individual fluorochromes to prevent fluorescence spillover. Monocytes are first enriched by gating based on forward and side scatter. The plots presented are representatives of at least six independent experiments conducted on whole blood from six or more participants as previously reported10. Figure 1A shows the initial gating of monocytes by cell scatter and exclusion of T cells by gating within the CD3- populatio...

Watch this Scientific Journal Video about A Simple Flow Cytometric Method to Measure Glucose Uptake and Glucose Transporter Expression for Monocyte Subpopulations in Whole Blood at JoVE.com

A Simple Flow Cytometric Method to Measure Glucose Uptake and Glucose Transporter Expression for Monocyte Subpopulations in Whole Blood

Monocytes are integral components of the human innate immune system that rely on glycolytic metabolism when activated. We describe a flow cytometry protocol to measure glucose transporter expression and glucose uptake by total monocytes and monocyte subpopulations in fresh whole blood.

Monocytes are innate immune cells that can be activated by pathogens and inflammation associated with certain chronic inflammatory diseases. Activation of ...

The overall goal of this methodology is to measure the uptake of glucose and its transporter on different monocyte subpopulations. This method can be used to answer key questions in the immunology field, such as What is the importance of immune cell metabolism in disease outcomes? The main advantages of these techniques are it is quick, easy to perform, requires no reactive material, and requires only a small volume of blood.Within one hour of collecting the blood samples, in citrate ACD-B anticoagulant tubes, place the samples into a biological safety cabinet. Next, add 100 microliters of blood from each sample into individual polypropylene tubes, and treat the cells with two milliliters of 1X lysing solution on ice, pipetting gently to mix. After 15 minutes, centrifuge the cells and follow this with two more spins in wash buffer.After the second wash, use a pipette to carefully remove as much of the supernatants as possible, and re-suspend the pellets in 100 microliters of wash buffer on ice. To identify the specific monocyte subpopulations, stain the cells with five microliters of the appropriate antibodies per 100 microliters of cells, for 30 minutes on ice in the the dark. At the end of the incubation, wash the samples two times in wash solution and fix the cells with 200 microliters of 0.5%formaldehyde in PBS.Then, analyze the cells within 24 hours on a flow cytometer capable of detecting four colors. To assess the glucose uptake of the monocyte subpopulations, transfer 90 microliters of blood from each sample into individual polypropylene tubes, and add 10 microliters of the fluorescent glucose analog of interest to the blood. Flick the tubes gently to mix, and cover the samples with aluminum foil.Then, place the cells at 37 degrees Celsius for 15 to 30 minutes, followed by their immediate transfer to ice. Next, add four milliliters of FACS lysing solution to the tubes, and centrifuge the cells. Then, perform a second centrifugation in wash buffer.Decant the supernatant, and stain the cells with the appropriate antibodies of interest for 30 minutes at four degrees Celsius in the dark. Then, wash the samples in four milliliters of ice-cold wash buffer, re-suspend the pellets in 200 to 300 microliters of ice-cold PBS, and analyze the tubes within 10 minutes. For flow cytometric analysis, first use the unstained and individually stained control samples to set the compensation.Next, in the appropriate single-cell analysis software, open the first sample in a forward by side scatter plot, and gate the monocytes as illustrated. Then, double-click the gated monocyte population, and gate the CD3-negative population. Now double-click on the CD3-negative population, and set the x-axis to display the CD14 staining, and the y-axis to display the CD16 staining.Next, to measure the uptake of glucose or its transporter in a specific monocyte subpopulation, generate the appropriate histograms. Then, where defined cell populations exist, use the control FITC igG samples to set the gate and determine the total percentage of CD14-positive monocytes in each sample. Here, the initial gating strategy for isolating the monocytes by cell scatter and T-cell exclusion by gating within the CD3-negative population, is shown.The monocytes are then gated for CD14 expression alone, or in combination with CD16 to identify the total monocytes or monocyte subpopulations. Distinct populations of CD14-positive Glut-1 glucose transporter positive monocytes may be observed, most notably in the circulating white blood cells obtained from HIV-positive individuals. CD14-positive Glut-1 positive cells may also be observed within specific monocyte subsets in HIV-uninfected individuals, although these populations are more pronounced in HIV-positive patients.As expected from the glucose transporter expression data, the glucose analog 2-NBDG, is also taken up in higher quantities by cells from HIV-positive individuals. Once mastered, this technique can be completed within one-and-a-half hours if performed properly. While attempting this procedure, it is important to limit light exposure to all regions.Following glucose analog uptakes, cells can be stained with cell surface antibodies to identify specific immune populations that you're interested in. After its development, this method can be used to determine how HIV affects immune cell metabolism, can also be explored by other researchers, in different fields, such as immunology, virology, and cancer research. After watching this video, you should have a good understanding on how to detect glucose transporter one, and glucose uptake in immune cells.Don't forget that when working with infectious agents, standard safety procedures should be employed.

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A Functional Whole Blood Assay to Measure Viability of Mycobacteria, using Reporter-Gene Tagged BCG or M.Tb (BCG lux/M.Tb lux)

Functional assays have long played a key role in measuring of immunogenicity of a given vaccine. This is conventionally expressed as serum bactericidal titers. Studies of serum bactericidal titers in response to childhood vaccines have enabled us to develop and validate cut-off levels for protective immune responses and such cut-offs are in routine use. No such assays have been taken forward into the routine assessment of vaccines that induce primarily cell-mediated immunity in the form of effector T cell responses, such as TB vaccines. In the animal model, the performance of a given vaccine candidate is routinely evaluated in standardized bactericidal assays, and all current novel TB-vaccine candidates have been subjected to this step in their evaluation prior to phase 1 human trials. The assessment of immunogenicity and therefore likelihood of protective efficacy of novel anti-TB vaccines should ideally undergo a similar step-wise evaluation in the human models now, including measurements in bactericidal assays.
Bactericidal assays in the context of tuberculosis vaccine research are already well established in the animal models, where they are applied to screen potentially promising vaccine candidates. Reduction of bacterial load in various organs functions as the main read-out of immunogenicity. However, no such assays have been incorporated into clinical trials for novel anti-TB vaccines to date.
Although there is still uncertainty about the exact mechanisms that lead to killing of mycobacteria inside human macrophages, the interaction of macrophages and T cells with mycobacteria is clearly required. The assay described in this paper represents a novel generation of bactericidal assays that enables studies of such key cellular components with all other cellular and humoral factors present in whole blood without making assumptions about their relative individual contribution. The assay described by our group uses small volumes of whole blood and has already been employed in studies of adults and children in TB-endemic settings. We have shown immunogenicity of the BCG vaccine, increased growth of mycobacteria in HIV-positive patients, as well as the effect of anti-retroviral therapy and Vitamin D on mycobacterial survival in vitro. Here we summarise the methodology, and present our reproducibility data using this relatively simple, low-cost and field-friendly model.
Note: Definitions/Abbreviations
BCG lux = M. bovis BCG, Montreal strain, transformed with shuttle plasmid pSMT1 carrying the luxAB genes from Vibrio harveyi, under the control of the mycobacterial GroEL (hsp60) promoter. 
CFU = Colony Forming Unit (a measure of mycobacterial viability).

A Functional Whole Blood Assay to Measure Viability of Mycobacteria, using Reporter-Gene Tagged BCG or M.Tb BCG lux/M.Tb lux

We describe an alternative approach to the enumeration of mycobacteria in vitro, which uses reporter-gene tagged mycobacteria instead of colony-forming units (CFU). &#x201C;Survival&#x201D; of organisms as well as host response-markers are measured simultaneously, providing a low-cost, versatile and functional system for studies of host/pathogen interactions in the context of tuberculosis.

Functional assays have long played a key role in measuring of immunogenicity of a given vaccine. This is conventionally expressed as serum bactericidal ...

A Simple and Efficient Method to Detect Nuclear Factor Activation in Human Neutrophils by Flow Cytometry

Neutrophils are the most abundant leukocytes in peripheral blood. These cells are the first to appear at sites of inflammation and infection, thus becoming the first line of defense against invading microorganisms. Neutrophils possess important antimicrobial functions such as phagocytosis, release of lytic enzymes, and production of reactive oxygen species. In addition to these important defense functions, neutrophils perform other tasks in response to infection such as production of proinflammatory cytokines and inhibition of apoptosis. Cytokines recruit other leukocytes that help clear the infection, and inhibition of apoptosis allows the neutrophil to live longer at the site of infection. These functions are regulated at the level of transcription. However, because neutrophils are short-lived cells, the study of transcriptionally regulated responses in these cells cannot be performed with conventional reporter gene methods since there are no efficient techniques for neutrophil transfection. Here, we present a simple and efficient method that allows detection and quantification of nuclear factors in isolated and immunolabeled nuclei by flow cytometry. We describe techniques to isolate pure neutrophils from human peripheral blood, stimulate these cells with anti-receptor antibodies, isolate and immunolabel nuclei, and analyze nuclei by flow cytometry. The method has been successfully used to detect NF-&kappa;B and Elk-1 nuclear factors in nuclei from neutrophils and other cell types. Thus, this method represents an option for analyzing activation of transcription factors in isolated nuclei from a variety of cell types.

Neutrophils are the most abundant leukocytes in blood. Neutrophils possess transcriptionally regulated functions such as production of proinflammatory cytokines and inhibition of apoptosis. These functions can be studied with the method presented here, which allows detection and quantification of nuclear factors by flow cytometry in isolated nuclei

Neutrophils  are the most abundant leukocytes in peripheral blood. These cells are the first  to appear at sites of inflammation and infection, thus ...

Isolation and Flow Cytometric Analysis of Glioma-infiltrating Peripheral Blood Mononuclear Cells

Our laboratory has recently demonstrated that natural killer (NK) cells are capable of eradicating orthotopically implanted mouse GL26 and rat CNS-1 malignant gliomas soon after intracranial engraftment if the cancer cells are rendered deficient in their expression of the &#946;-galactoside-binding lectin galectin-1 (gal-1). More recent work now shows that a population of Gr-1+/CD11b+ myeloid cells is critical to this effect. To better understand the mechanisms by which NK and myeloid cells cooperate to confer gal-1-deficient tumor rejection we have developed a comprehensive protocol for the isolation and analysis of glioma-infiltrating peripheral blood mononuclear cells (PBMC). The method is demonstrated here by comparing PBMC infiltration into the tumor microenvironment of gal-1-expressing GL26 gliomas with those rendered gal-1-deficient via shRNA knockdown. The protocol begins with a description of&#160;how to culture and prepare GL26 cells for inoculation into the syngeneic C57BL/6J mouse brain. It then explains the steps involved in the isolation and flow cytometric analysis of glioma-infiltrating PBMCs from the early brain tumor microenvironment. The method is adaptable to a number of in vivo experimental designs in which temporal data on immune infiltration into the brain is required. The method is sensitive and highly reproducible, as glioma-infiltrating PBMCs can be isolated from intracranial tumors as soon as 24 hr post-tumor engraftment with similar cell counts observed from time point matched tumors throughout independent experiments. A single experimentalist can perform the method from brain harvesting to flow cytometric analysis of glioma-infiltrating PBMCs in roughly 4-6 hr depending on the number of samples to be analyzed. Alternative glioma models and/or cell-specific detection antibodies may also be used at the experimentalists&#8217; discretion to assess the infiltration of several other immune cell types of interest without the need for alterations to the overall procedure.

Presented here is a straightforward method for the isolation and flow cytometric analysis of glioma-infiltrating peripheral blood mononuclear cells that yields time-dependent quantitative data on the number and activation status of immune cells entering the early brain tumor microenvironment.

Our laboratory has recently demonstrated that natural killer (NK) cells are capable of eradicating orthotopically implanted mouse GL26 and rat CNS-1 ...

Measuring Granulocyte and Monocyte Phagocytosis and Oxidative Burst Activity in Human Blood

The granulocyte and monocyte phagocytosis and oxidative burst (OB) activity assay can be used to study the innate immune system. This manuscript provides the necessary methodology to add this assay to an exercise immunology arsenal. The first step in this assay is to prepare two aliquots ("H" and "F") of whole blood (heparin). Then, dihydroethidium is added to the H aliquot, and both aliquots are incubated in a warm water bath followed by a cold water bath. Next, Staphylococcus aureus (S. aureus) is added to the H aliquot and fluorescein isothiocyanate-labeled S. aureus is added to the F aliquot (bacteria:phagocyte = 8:1), and both aliquots are incubated in a warm water bath followed by a cold water bath. Then, trypan blue is added to each aliquot to quench extracellular fluorescence, and the cells are washed with phosphate-buffered saline. Next, the red blood cells are lysed, and the white blood cells are fixed. Finally, a flow cytometer and appropriate analysis software are used to measure granulocyte and monocyte phagocytosis and OB activity. This assay has been used for over 20 years. After heavy and prolonged exertion, athletes experience a significant but transient increase in phagocytosis and an extended decrease in OB activity. The post-exercise increase in phagocytosis is correlated with inflammation. In contrast to normal weight individuals, granulocyte and monocyte phagocytosis is chronically elevated in overweight and obese participants, and is modestly correlated with C-reactive protein. In summary, this flow cytometry-based assay measures the phagocytosis and OB activity of phagocytes and can be used as an additional measure of exercise- and obesity-induced inflammation.

The purpose of this manuscript is to present a method for measuring monocyte and granulocyte phagocytosis and oxidative burst activity in human blood samples.

The granulocyte and monocyte phagocytosis and oxidative burst (OB) activity assay can be used to study the innate immune system. This manuscript provides ...

Flow Cytometric Analysis of Natural Killer Cell Lytic Activity in Human Whole Blood

NK cell cytotoxicity is a widely used measure to determine the effect of outside intervention on NK cell function. However, the accuracy and reproducibility of this assay can be considered unstable, either because of user&#39;s errors or because of the sensitivity of NK cells to experimental manipulation. To eliminate these issues, a workflow that reduces them to a minimum was established and is presented here. To illustrate, we obtained blood samples, at various time points, from runners (n = 4) that were submitted to an intense bout of exercise. First, NK cells are simultaneously identified and isolated through CD56 tagging and magnetic-based sorting, directly from whole blood and from as little as one milliliter. The sorted NK cells are removed of any reagent or capping antibodies. They can be counted in order to establish an accurate NK cell count per milliliter of blood. Secondly, the sorted NK cells (effectors cells or E) can be mixed with 3,3&#39;-Diotadecyloxacarbocyanine Perchlorate (DiO) tagged K562 cells (target cells or T) at an assay-optimal 1:5 T:E ratio, and analyzed using an imaging flow-cytometer that allows for the visualization of each event and the elimination of any false positive or false negatives (such as doublets or effector cells). This workflow can be completed in about 4 h, and allows for very stable results even when working with human samples. When available, research teams can test several experimental interventions in human subjects, and compare measurements across several time points without compromising the data&#39;s integrity.

This work describes an advanced workflow for the accurate and fast determination of NK (Natural Killer) cell count and NK cell cytotoxicity in human blood samples.

NK cell cytotoxicity is a widely used measure to determine the effect of outside intervention on NK cell function. However, the accuracy and ...

Generation of Human Monocyte-derived Dendritic Cells from Whole Blood

Dendritic cells (DCs) recognize foreign structures of different pathogens, such as viruses, bacteria, and fungi, via a variety of pattern recognition receptors (PRRs) expressed on their cell surface and thereby activate and regulate immunity. 
The major function of DCs is the induction of adaptive immunity in the lymph nodes by presenting antigens via MHC I and MHC II molecules to na&#239;ve T lymphocytes. Therefore, DCs have to migrate from the periphery to the lymph nodes after the recognition of pathogens at the sites of infection. For in vitro experiments or DC vaccination strategies, monocyte-derived DCs are routinely used. These cells show similarities in physiology, morphology, and function to conventional myeloid dendritic cells. They are generated by interleukin 4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation of monocytes isolated from healthy donors. Here, we demonstrate how monocytes are isolated and stimulated from anti-coagulated human blood after peripheral blood mononuclear cell (PBMC) enrichment by density gradient centrifugation. Human monocytes are differentiated into immature DCs and are ready for experimental procedures in a non-clinical setting after 5 days of incubation.

Here, we demonstrate how monocytes are isolated by magnetic bead separation from peripheral blood mononuclear cells after density gradient centrifugation of human anti-coagulated blood. Following incubation for 5 days, human monocytes are differentiated into immature dendritic cells and are ready for experimental procedures in a non-clinical setting.

Dendritic cells (DCs) recognize foreign structures of different pathogens, such as viruses, bacteria, and fungi, via a variety of pattern recognition ...

Use of a Monocyte Monolayer Assay to Evaluate Fc&#947; Receptor-mediated Phagocytosis

Although originally developed for predicting transfusion outcomes of serologically incompatible blood, the monocyte monolayer assay (MMA) is a highly versatile in vitro assay that can be modified to examine different aspects of antibody and Fc&#947; receptor (Fc&#947;R)-mediated phagocytosis in both research and clinical settings. The assay utilizes adherent monocytes from peripheral blood mononuclear cells isolated from mammalian whole blood. MMA has been described for use in both human and murine investigations. These monocytes express Fc&#947;Rs (e.g., Fc&#947;RI, Fc&#947;RIIA, Fc&#947;RIIB, and Fc&#947;RIIIA) that are involved in immune responses. The MMA exploits the mechanism of Fc&#947;R-mediated interactions, phagocytosis in particular, where antibody-sensitized red blood cells (RBCs) adhere to and/or activate Fc&#947;Rs and are subsequently phagocytosed by the monocytes. In vivo, primarily tissue macrophages found in the spleen and liver carry out Fc&#947;R-mediated phagocytosis of antibody-opsonized RBCs, causing extravascular hemolysis. By evaluating the level of phagocytosis using the MMA, different aspects of the in vivo Fc&#947;R-mediated process can be investigated. Some applications of the MMA include predicting the clinical relevance of allo- or autoantibodies in a transfusion setting, assessing candidate drugs that promote or inhibit phagocytosis, and combining the assay with fluorescent microscopy or traditional Western immunoblotting to investigate the downstream signaling effects of Fc&#947;R-engaging drugs or antibodies. Some limitations include the laboriousness of this technique, which takes a full day from start to finish, and the requirement of research ethics approval in order to work with mammalian blood. However, with diligence and adequate training, the MMA results can be obtained within a 24-h turnover time.

The monocyte monolayer assay (MMA) is an in vitro assay that utilizes isolated primary monocytes obtained from mammalian peripheral whole blood to evaluate Fc&#947; receptor (Fc&#947;R)-mediated phagocytosis.

Although originally developed for predicting transfusion outcomes of serologically incompatible blood, the monocyte monolayer assay (MMA) is a highly ...

A Simple Red Blood Cell Lysis Method for the Establishment of B Lymphoblastoid Cell Lines

A number of methods exist for the transformation of B lymphocytes by the Epstein Barr virus in vitro into immortalized cell lines. We have developed a new method with a powerful and simple strategy for the establishment of B-LCLs, the red blood cell lysis method. This method simplified the PBMC separation procedure with red blood cell removal, and used as little as 0.5 mL of whole blood for establishing EBV-immortalized cell lines, which can proliferate to large cell numbers in a relatively short amount time with a 100% success rate. The method is simple, reliable, time saving, and applicable to treating a large number of the clinical samples.

A simple red blood cell lysis method for establishing B-LCLs was developed with high immortalization efficiency, requiring a small amount of blood and saving time from initiation to cryopreservation.

A number of methods exist for the transformation of B lymphocytes by the Epstein Barr virus in vitro into immortalized cell lines. We have developed a new ...

Characterization of Human Monocyte Subsets by Whole Blood Flow Cytometry Analysis

Monocytes are key contributors in various inflammatory disorders and alterations to these cells, including their subset proportions and functions, can have pathological significance. An ideal method for examining alterations to monocytes is whole blood flow cytometry as the minimal handling of samples by this method limits artifactual cell activation. However, many different approaches are taken to gate the monocyte subsets leading to inconsistent identification of the subsets between studies. Here we demonstrate a method using whole blood flow cytometry to identify and characterize human monocyte subsets (classical, intermediate, and non-classical). We outline how to prepare the blood samples for flow cytometry, gate the subsets (ensure contaminating cells have been removed), and determine monocyte subset expression of surface markers &#8212; in this example M1 and M2 markers. This protocol can be extended to other studies that require a standard gating method for assessing monocyte subset proportions and monocyte subset expression of other functional markers.

Here we present a protocol for characterizing monocyte subsets by whole blood flow cytometry. This includes outlining how to gate the subsets and assess their expression of surface markers and giving an example of the assessment of the expression of M1 (inflammatory) and M2 markers (anti-inflammatory).

Monocytes are key contributors in various inflammatory disorders and alterations to these cells, including their subset proportions and functions, can ...

Simultaneous Study of the Recruitment of Monocyte Subpopulations Under Flow In Vitro

The recruitment of monocytes from the blood to targeted peripheral tissues is critical to the inflammatory process during tissue injury, tumor development and autoimmune diseases. This is facilitated through a process of capture from free flow onto the luminal surface of activated endothelial cells, followed by their adhesion and transendothelial migration (transmigration) into the underlying affected tissue. However, the mechanisms that support the preferential and context-dependent recruitment of monocyte subpopulations are still not fully understood. Therefore, we have developed a method that allows the recruitment of different monocyte subpopulations to be simultaneously visualized and measured under flow. This method, based on time-lapse confocal imaging, allows for the unambiguous distinction between adherent and transmigrated monocytes. Here, we describe how this method can be used to simultaneously study the recruitment cascade of pro-angiogenic and non-angiogenic monocytes in vitro. Furthermore, this method can be extended to study the different steps of recruitment of up to three monocyte populations.

Here, we present an integrated protocol that measures monocyte subpopulation trafficking under flow in vitro by use of specific surface markers and confocal fluorescence microscopy. This protocol can be used to explore sequential recruitment steps as well as to profile other leukocyte subtypes using other specific surface markers.

The recruitment of monocytes from the blood to targeted peripheral tissues is critical to the inflammatory process during tissue injury, tumor development ...