Name: isolation protocol of mouse monocyte-derived dendritic cells and their subsequent in vitro activation with tumor immune complexes
Uploaded: 2018-05-31T13:00:00
Description: Watch this Scientific Journal Video about Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes at JoVE.com

The protocols below refer to the isolation of mouse MoDC, yet the overall principles may apply to other DC subsets cells, as well. 12 - 16-week-old C57Bl/6j mice were maintained in an American Association for the Accreditation of Laboratory Animal Care&#8211;accredited animal facility. All protocols were approved by Stanford University and Tel-Aviv University Institutional Animal Care and Use Committee.
1. Isolation of Tumor Associated Monocyte-Derived DC
<ol>
	<li>In a laminar flow hood, re...

<ol>
	<li>Steinman, R. M., Banchereau, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Taking+dendritic+cells+into+medicine.">Taking dendritic cells into medicine.</a> Nature. 449 (7161), 419-426 (2007).</li><li>Palucka, K., Banchereau, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dendritic-cell-based+therapeutic+cancer+vaccines.">Dendritic-cell-based therapeutic cancer vaccines.</a> Immunity. 39 (1), 38-48 (2013).</li><li>Mildner, A., Jung, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+function+of+dendritic+cell+subsets.">Development and function of dendritic cell subsets.</a> Immunity. 40 (5), 642-656 (2014).</li><li>Merad, M., Sathe, P., Helft, J., Miller, J., Mortha, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+dendritic+cell+lineage:+ontogeny+and+function+of+dendritic+cells+and+their+subsets+in+the+steady+state+and+the+inflamed+setting.">The dendritic cell lineage: ontogeny and function of dendritic cells and their subsets in the steady state and the inflamed setting.</a> Annual review of immunology. 31, 563-604 (2013).</li><li>Guilliams, 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=Dendritic+cells,+monocytes+and+macrophages:+a+unified+nomenclature+based+on+ontogeny.">Dendritic cells, monocytes and macrophages: a unified nomenclature based on ontogeny.</a> Nature reviews. 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Given the large number of DC required for vaccinating mice (approximately 2-4 x 106 DC per one mouse), most of the vaccination strategies in mice are based on isolation of DC from BM and spleen followed by their ex vivo activation. However, attempts to activate tumor DC in vivo, using the same conditions for activating spleen and BM DC, have often been unsuccessful in producing effective immunity. In two subsequent publications, Carmi et al. have found that blood and tumor MoDC diffe...

Since their discovery, dendritic cells (DC) have been a focus of extensive research due to their unique ability to skew T cell differentiation1. Over the past several decades, an extensive research effort has sought to define the various DC subsets and their function during tumor progression and immunity 2. DCs are composed of heterogeneous cell populations that differ from each other in their pattern-recognition receptors, tissue distribution, and migratory and antigen presentation capabilities3,4,5. Compared to other DC subsets, monocyte-derived DC (MoDC) are far more abundant in tumors and can be easily generated from circulating or tumor-infiltrating monocytes6,7. Therefore, many clinical trials seeking to take advantage of their relative prevalence are based on in vivo and ex vivo manipulation of autologous MoDC in order to elicit T cell immunity 8,9.
Similarly, DC-based vaccination of experimental tumor models requires 2-3 serial injections, 5-7 days apart, of 1-2 x 106 activated DC pulsed with tumor antigens. Therefore, to achieve this large number of DC, most mouse studies have primarily used MoDC cultured from bone marrow (BM) precursors in GM-CSF for 7-9 days (IL-4 is not needed in the mouse setting)10,11. Nonetheless, given that GM-CSF knockout mice have overall normal DC compartment 12,13, and given the mixed populations obtained from that culture,14 the physiological relevance of these DC has been called into question.
Alternatively, DC may be routinely isolated from spleen cells. However, DC comprise only about 0.3-0.8% of total spleen cells (resulting in approximately 7 x 105 DC/spleen), and of these cells, only CD103+ DC and MoDC can migrate back to lymphoid organs. Since MoDCs comprise approximately 10-15% of splenic DC populations15,16, most isolation protocols yield approximately 1 x 105 MoDC per spleen. Expansion of MoDC can be achieved by injecting transfected B16 cells that secrete GM-CSF, resulting in a 100-fold increase in splenic MoDC17. However, the use of MoDC for developing DC vaccines is limited since this procedure cannot be done in humans and the obtained MoDC are already highly activated.
In addition to obtaining adequate numbers of DC, another challenge for developing effective DC vaccines against autologous cancer cells involves the lack of sufficient danger signals in the tumor setting to fully activate DC. Induction of co-stimulatory signals is usually achieved through activation of pattern-recognition receptors (PRR), or c-type lectin signaling pathways18,19,20,21. A further approach for activating DC exploits their ability to take up antigens through interactions with surface Fc&#947; receptors (Fc&#947;R). Indeed, a number of important manuscripts have shown that injection of MoDC from BM precursors activated with tumor-IgG IC can prevent tumor growth in prophylactic settings, and can lead to the eradication of established tumors22,23.
In two recent papers, Carmi et al. discovered that in contrast to BMDC and spleen DC, MoDC from the blood and tumors cannot respond to IgG IC without additional stimuli. This was found to be due to the presence of high intracellular levels of tyrosine phosphatases regulating Fc&#947;R signaling24,25. By defining a critical checkpoint in DC, this work provided an important insight into the requirements for successful DC-based vaccination. The requirement for additional stimuli to enable Fc&#947;R signaling, and presumably signaling from other lectin receptors utilizing a similar phosphorylation cascade, thus underscores the need for avoiding the priming of DC during their isolation.
Therefore, the present protocol describes the isolation of MoDC from blood and tumors, which differ markedly from BM and spleen DC, and highlights precautions worth considering during the process.

<table>
	<tbody>
		<tr>
			<td>Ficoll-Paque PREMIUM</td>
			<td>GE-Healthcare</td>
			<td>17-5442-02</td>
			<td></td>
		</tr>
		<tr>
			<td>OptiPrep</td>
			<td>StemCell Technologies</td>
			<td>07820</td>
			<td></td>
		</tr>
		<tr>
			<td>CD45 MicroBeads</td>
			<td>Miltenyi</td>
			<td>130-052-301</td>
			<td></td>
		</tr>
		<tr>
			<td>EasySep Monocyte Isolation Kit</td>
			<td>StemCell Technologies</td>
			<td>19861</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase IV</td>
			<td>Sigma</td>
			<td>C9697-50MG</td>
			<td>Test each lot for endotoxin</td>
		</tr>
		<tr>
			<td>DNase I</td>
			<td>Sigma</td>
			<td>DN25-10MG</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS</td>
			<td>ThermoFisher</td>
			<td>14025092</td>
			<td></td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>ThermoFisher</td>
			<td>16140071</td>
			<td>Test each lot for endotoxin</td>
		</tr>
		<tr>
			<td>PE-CD11c</td>
			<td>Biolegend</td>
			<td>117307</td>
			<td></td>
		</tr>
		<tr>
			<td>APC-CD11b</td>
			<td>Biolegend</td>
			<td>101211</td>
			<td></td>
		</tr>
		<tr>
			<td>Brilliant Violet 650 MHCII</td>
			<td>Biolegend</td>
			<td>107641</td>
			<td></td>
		</tr>
		<tr>
			<td>AF48- CD86</td>
			<td>Biolegend</td>
			<td>105017</td>
			<td></td>
		</tr>
		<tr>
			<td>APC/Cy7-Ly-C6</td>
			<td>Biolegend</td>
			<td>108423</td>
			<td></td>
		</tr>
		<tr>
			<td>PE/Cy7-CD15</td>
			<td>Biolegend</td>
			<td>135523</td>
			<td></td>
		</tr>
	</tbody>
</table>

isolation protocol of mouse monocyte-derived dendritic cells and their subsequent in vitro activation with tumor immune complexes

Dendritic cells (DC) are heterogeneous cell populations that differ in their cell membrane markers, migration patterns and distribution, and in their antigen presentation and T cell activation capacities. Since most vaccinations of experimental tumor models require millions of DC, they are widely isolated from the bone marrow or spleen. However, these DC significantly differ from blood and tumor DC in their responses to immune complexes (IC), and presumably to other Syk-coupled lectin receptors. Importantly, given the sensitivity of DC to danger-associated molecules, the presence of endotoxins or antibodies that crosslink activation receptors in one of the isolating steps could result in the priming of DC and thus affect the parameters, or at least the dosage, required to activate them. Therefore, here we describe a detailed protocol for isolating MoDC from blood and tumors while avoiding their premature activation. In addition, a protocol is provided for MoDC activation with tumor IC, and their subsequent analyses.

We initially compared the capacity of antibodies from na&#239;ve syngeneic and allogeneic mice to bind to tumor cells. To this end, B16F10 and LMP tumor cell lines were fixed in paraformaldehyde and washed extensively. B16F10 is a melanoma cell line, which was originally isolated from lung metastases in C57Bl/6 mice. LMP is a pancreatic tumor cell that was isolated from KrasG12D/+, LSL-Trp53R172H/+, and Pdx-1-Cre mice, and grows steadily in 129F1 mice. To obtain IC, tumor cells were incub...

Watch this Scientific Journal Video about Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes at JoVE.com

Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes

Monocyte-derived DC (MoDC) can sense minor amounts of danger-associated molecules and are therefore easily primed. We provide a detailed protocol for the isolation of MoDC from blood and tumors and their activation with immune complexes while highlighting key precautions that should be considered in order to avoid their premature activation.

Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes

Dendritic cells (DC) are heterogeneous cell populations that differ in their cell membrane markers, migration patterns and distribution, and in their ...

This method is designed to help scientists to isolate monocyte-derived DCs from the blood and tumors of tumor-bearing mice in order to study their immunostimulatory properties. I think that the main advantage of this procedure compared to other method is that the obtained monocyte-derived DCs better reflect their activation state in the tumor and blood. The hardest thing is probably to make sure that all of your reagents and tools are sterile and that you will not introduce contamination during this procedure.I've been isolating myeloid cells and dendritic cells from tumors for over 15 years now, and I had the idea of this method when I noticed that different isolation protocols resulted in different patterns of cell activation. Demonstrating the procedure will be Mrs. Santana-Magal, who is a grad student in my lab.After euthanizing the mice using carbon dioxide inside a laminar flow hood, extract the tumors and place them in RPMI medium without fetal bovine serum. Then, use surgery scissors to slice the tumor into small pieces. Transfer all of the tumor pieces from a single mouse to a 30-milliliter flat-bottom tube containing HBSS buffer supplemented with collagenase IV and DNase I along with the magnetic stir bars.Incubate the tube with the tumor pieces on a shaker at 37 degrees Celsius with a magnetic stirrer inside at 200 to 400 revolutions per minute for 20 to 30 minutes. Next, filter the cells through a 70-micrometer cell strainer. Then, centrifuge the cells at 400 times g for five to 10 minutes at four degrees Celsius.After centrifugation, add 1.5 milliliters of density gradient medium stock solution to 8.5 milliliters of HBSS. Then, mix the density gradient medium vigorously. Next, pipette the mixture to the pellet.Centrifuge the cell suspension at 400 times g for 20 minutes at room temperature. Decant the supernatant after the centrifugation is over. After washing the pelleted cells twice, resuspend in one milliliter of isolation buffer.Add the cell suspension to 30 microliters of CD11b conjugated magnetic beads. Next, incubate the mixture at four degrees Celsius for 15 minutes. Following centrifugation, remove the supernatant and resuspend the pellet in one milliliter of isolation buffer.Apply the cell suspension on a pre-washed magnetic column. Next, use three milliliters of isolation buffer to wash the column twice. Then, remove the column from the magnet.Next, add six milliliters of isolation buffer in the column. Push with a plunger to flush out the magnetically labeled cells in a sterile collection tube. Once again, centrifuge the cells at 400 times g for five to 10 minutes at four degrees Celsius.After resuspending and staining the cells, sort the cells by gating the small cells, using small side and small forward scatter. After euthanizing the mouse, spray 70%ethanol on it. Then, use surgical scissors to remove the skin covering the heart under the laminar hood.Next, clean the scissors with ethanol. Wash the cavity with 20-millimolar EDTA HBSS, and use the scissors to cut the right atrium of the heart. Then, use a 10-milliliter syringe with a 25-gauge needle to slowly flush the right ventricle of the heart with 20-millimolar EDTA HBSS.Then, use a sterile syringe to draw blood from the pleural cavity. Transfer the blood in a tube containing heparan sulfate and EDTA. Next, pipette the blood on the density gradient medium.Centrifuge the blood cells at 400 times g for 15 minutes at room temperature with low brake. After centrifugation, collect the mononuclear cells in a tube. Dissolve the cells in 10 milliliters of isolation buffer to wash the cells.Again, centrifuge the cells at 400 times g for five to 10 minutes at four degrees Celsius. To select the CD11b cells, resuspend the cell pellet in one milliliter of isolation buffer. Incubate for 15 minutes with 50 microliters of CD11b conjugated magnetic beads at four degrees Celsius.Recentrifuge at 400 times g for five to 10 minutes at four degrees Celsius. Then, remove the supernatant. Resuspend the pellet in one milliliter of isolation buffer.Next, apply the cell suspension on a pre-washed magnetic column. Wash the column with isolation buffer twice. Remove the column from the magnet, and add six milliliters of isolation buffer on the column.Next, flush out the magnetically labeled cells in a sterile collection tube by pushing the plunger. Centrifuge the cells at 400 times g for five to 10 minutes at four degrees Celsius. Resuspend the cells in isolation buffer and stain with fluorophore-conjugated antibodies.Sort the cells by gating the small cells using small side and small forward scatter. First, fix the cells in 1.8%buffered paraformaldehyde for 10 minutes at room temperature. Seed the cell suspension in each well of a U-shaped 96-well plate.Next, add varying dilutions of tumor-binding antibodies in each well. Thereafter, incubate the cells on ice for 15 to 20 minutes. After incubation, wash the cells with 150 microliters of phosphate buffered saline.Then, centrifuge at 400 times g for five to 10 minutes at four degrees Celsius. Post-centrifugation, expel the supernatant and wash the cells twice. Dissolve the cells in 100 microliters of FACS buffer containing fluorophore-conjugated secondary antibody.Next, incubate the plate on ice for 15 to 20 minutes. After 15 to 20 minutes, add 200 microliters of FACS buffer to wash the cells. Centrifuge the plate at 400 times g for five to 10 minutes.Decant the supernatant. Conduct flow cytometry to analyze the tumor binding and to determine the minimal concentration of immunoglobulin G required to coat the cells. Once the cells are coated with minimal immunoglobulin G concentration, add the CFSE-labeled tumor immune complex to the monocyte-derived dendritic cells in a one-to-five ratio.Then, incubate the mixture for 12 to 16 hours overnight in complete medium. Perform FACS analysis of the monocyte-derived dendritic cell activation. Mean fluorescence intensity is calculated following flow cytometric analysis to study the presence of IgG and M antibodies that bind LMP tumor cells ex vivo.Results show that the IgG antibodies from C57-Black/6 allogeneic mice bind the tumor cells much stronger than the antibodies from the 129S1 syngeneic mice. Then, the mean fluorescence intensity of the binding capacity of B16F10 tumor cells with the IgG is calculated. IgG obtained from 129S1 allogeneic mice shows 10-fold higher staining intensity with B16F10 tumor in comparison to syngeneic IgG from C57-Black/6 mice.Next, DIC microscopic images are captured to show the tumor-associated, monocyte-derived dendritic cells from the B16F10 tumors. Here, DIC images are captured to show the inflammatory and patrolling monocyte-derived dendritic cells isolated from the blood of B16F10 tumor-bearing mice. Flow cytometric analysis is also done to compare the activation patterns of monocyte-derived dendritic cells from the spleen and the bone marrow with that of the tumor and blood on incubating with the immune complex.The result shows increased CD86 and MHC II expression by the bone marrow and splenic dendritic cells with the immune complexes. Then, confocal immunohistochemistry is done, which shows tumor uptake and MHC II expression when the dendritic cells are incubated with the CFSE-labeled tumor immune complex. Once mastered, this procedure can be done in a few hours depending on the number of mice you are using.While attempting this procedure, it's important to remember to keep all your reagents and tools sterile at all time. Mouse fur is a major source for contaminations. Make sure that none of the hairs are touching your tissues.We hope that after watching this video, you'll have a good understanding of how to isolate monocyte-derived DCs from mouse blood and tumors and how to subsequently activate them with immune complex cells while avoiding their premature activation.

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Research

JoVE Journal

Cancer Research

Isolation of Circulating Tumor Cells in an Orthotopic Mouse Model of Colorectal Cancer

Despite the advantages of easy applicability and cost-effectiveness, subcutaneous mouse models have severe limitations and do not accurately simulate tumor biology and tumor cell dissemination. Orthotopic mouse models have been introduced to overcome these limitations; however, such models are technically demanding, especially in hollow organs such as the large bowel. In order to produce uniform tumors which reliably grow and metastasize, standardized techniques of tumor cell preparation and injection are critical. 
We have developed an orthotopic mouse model of colorectal cancer (CRC) which develops highly uniform tumors and can be used for tumor biology studies as well as therapeutic trials. Tumor cells from either primary tumors, 2-dimensional (2D) cell lines or 3-dimensional (3D) organoids are injected into the cecum and, depending on the metastatic potential of the injected tumor cells, form highly metastatic tumors. In addition, CTCs can be found regularly. We here describe the technique of tumor cell preparation from both 2D cell lines and 3D organoids as well as primary tumor tissue, the surgical and injection techniques as well as the isolation of CTCs from the tumor-bearing mice, and present tips for troubleshooting.

We describe the establishment of orthotopic colorectal tumors via injection of tumor cells or organoids into the cecum of mice and the subsequent isolation of circulating tumor cells (CTCs) from this model.

Despite the advantages of easy applicability and cost-effectiveness, subcutaneous mouse models have severe limitations and do not accurately simulate ...

Moving Upwards: A Simple and Flexible In Vitro Three-dimensional Invasion Assay Protocol

Although 3D invasion assays have been developed, the challenge remains to study cells without affecting the integrity of their microenvironment. Traditional 3D assays such as the Boyden Chamber require that cells are displaced from the original culture location and moved to a new environment. Not only does this disrupt the cellular processes that are intrinsic to the microenvironment, but it often results in a loss of cells. These problems are especially challenging when dealing with cells that are either rare, or extremely sensitive to their microenvironment. Here, we describe the development of a 3D invasion assay that avoids both concerns. In this assay, cells are plated within a small well and an ECM matrix containing a chemoattractant is laid atop the cells. This requires no cell displacement, and allows the cells to invade upwards into the matrix. In this assay, cell invasion as well as cell morphology can be assessed within the collagen gel. Using this assay, we characterize the invasive capacity of rare and sensitive cells; the hybrid cells resulting from fusion between breast cancer cells MCF7 and mesenchymal/multipotent stem/stroma cells (MSCs).

Moving Upwards: A Simple and Flexible In Vitro Three-dimensional Invasion Assay Protocol

This protocol describes an inverted vertical invasion assay that could be used to quantify the migration and invasion capabilities of cells in a three-dimensional setting while preserving the cell microenvironment. This assay is suitable for rare and/or sensitive cells.

Although 3D invasion assays have been developed, the challenge remains to study cells without affecting the integrity of their microenvironment. ...

Isolation and Characterization of Tumor-initiating Cells from Sarcoma Patient-derived Xenografts

The existence and importance of tumor-initiating cells (TICs) have been supported by increasing evidence during the past decade. These TICs have been shown to be responsible for tumor initiation, metastasis, and drug resistance. Therefore, it is important to develop specific TIC-targeting therapy in addition to current chemotherapy strategies, which mostly focus on the bulk of non-TICs. In order to further understand the mechanism behind the malignancy of TICs, we describe a method to isolate and to characterize TICs in human sarcomas. Herein, we show a detailed protocol to generate patient-derived xenografts (PDXs) of human sarcomas and to isolate TICs by fluorescence-activated cell sorting (FACS) using human leukocyte antigen class I (HLA-1) as a negative marker. Also, we describe how to functionally characterize these TICs, including a sphere formation assay and a tumor formation assay, and to induce differentiation along mesenchymal pathways. The isolation and characterization of PDX TICs provide clues for the discovery of potential targeting therapy reagents. Moreover, increasing evidence suggests that this protocol may be further extended to isolate and characterize TICs from other types of human cancers.

We describe a detailed protocol for the isolation of tumor-initiating cells from human sarcoma patient-derived xenografts by fluorescence-activated cell sorting, using human leukocyte antigen-1 (HLA-1) as a negative marker, and for the further validation and characterization of these HLA-1-negative tumor-initiating cells.

The existence and importance of tumor-initiating cells (TICs) have been supported by increasing evidence during the past decade. These TICs have been ...

Enrichment and Characterization of the Tumor Immune and Non-immune Microenvironments in Established Subcutaneous Murine Tumors

The tumor immune microenvironment (TIME) has recently been recognized as a critical mediator of treatment response in solid tumors, especially for immunotherapies. Recent clinical advances in immunotherapy highlight the need for reproducible methods to accurately and thoroughly characterize the tumor and its associated immune infiltrate. Tumor enzymatic digestion and flow cytometric analysis allow broad characterization of numerous immune cell subsets and phenotypes; however, depth of analysis is often limited by fluorophore restrictions on panel design and the need to acquire large tumor samples to observe rare immune populations of interest. Thus, we have developed an effective and high throughput method for separating and enriching the tumor immune infiltrate from the non-immune tumor components. The described tumor digestion and centrifugal density-based separation technique allows separate characterization of tumor and tumor immune infiltrate fractions and preserves cellular viability, and thus, provides a broad characterization of the tumor immunologic state. This method was used to characterize the extensive spatial immune heterogeneity in solid tumors, which further demonstrates the need for consistent whole tumor immunologic profiling techniques. Overall, this method provides an effective and adaptable technique for the immunologic characterization of subcutaneous solid murine tumors; as such, this tool can be used to better characterize the tumoral immunologic features and in the preclinical evaluation of novel immunotherapeutic strategies.

Here we describe a method to separate and enrich components of the tumor immune and non-immune microenvironment in established subcutaneous tumors. This technique allows for the separate analysis of tumor immune infiltrate and non-immune tumor fractions which can permit comprehensive characterization of the tumor immune microenvironment.

The tumor immune microenvironment (TIME) has recently been recognized as a critical mediator of treatment response in solid tumors, especially for ...

Mesenchymal Stem Cell Isolation from Pulp Tissue and Co-Culture with Cancer Cells to Study Their Interactions

Cancer as a multistep process and complicated disease is not only regulated by individual cell proliferation and growth but also controlled by tumor environment and cell-cell interactions. Identification of cancer and stem cell interactions, including changes in extracellular environment, physical interactions, and secreted factors, might enable the discovery of new therapy options. We combine known co-culture techniques to create a model system for mesenchymal stem cells (MSCs) and cancer cell interactions. In the current study, dental pulp stem cells (DPSCs) and PC-3 prostate cancer cell interactions were examined by direct and indirect co-culture techniques. Condition medium (CM) obtained from DPSCs and 0.4 &#181;m pore sized trans-well membranes were used to study paracrine activity. Co-culture of different cell types together was performed to study direct cell-cell interaction. The results revealed that CM increased cell proliferation and decreased apoptosis in prostate cancer cell cultures. Both CM and trans-well system increased cell migration capacity of PC-3 cells. Cells stained with different membrane dyes were seeded into the same culture vessels, and DPSCs participated in a self-organized structure with PC-3 cells under this direct co-culture condition. Overall, the results indicated that co-culture techniques could be useful for cancer and MSC interactions as a model system.

We provide protocols for evaluation of mesenchymal stem cells isolated from dental pulp and prostate cancer cell interactions based on direct and indirect co-culture methods. Condition medium and trans-well membranes are suitable to analyze indirect paracrine activity. Seeding differentially stained cells together is an appropriate model for direct cell-cell interaction.

Cancer as a multistep process and complicated disease is not only regulated by individual cell proliferation and growth but also controlled by tumor ...

Real Time Detection of In Vitro Tumor Cell Apoptosis Induced by CD8+ T Cells to Study Immune Suppressive Functions of Tumor-infiltrating Myeloid Cells

Potentiation of the tumor-killing ability of CD8+ T cells in tumors, along with their efficient tumor infiltration, is a key element of successful immunotherapies. Several studies have indicated that tumor infiltrating myeloid cells (e.g., myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs)) suppress cytotoxicity of CD8+ T cells in the tumor microenvironment, and that targeting these regulatory myeloid cells can improve immunotherapies. Here, we present an in vitro assay system to evaluate immune suppressive effects of monocytic-MDSCs and TAMs on the tumor-killing ability of CD8+ T cells. To this end, we first cultured na&#239;ve splenic CD8+ T cells with anti-CD3/CD28 activating antibodies in the presence or absence of suppressor cells, and then co-cultured the pre-activated T cells with target cancer cells in the presence of a fluorogenic caspase-3 substrate. Fluorescence from the substrate in cancer cells was detected by real-time fluorescence microscopy as an indicator of T-cell induced tumor cell apoptosis. In this assay, we can successfully detect the increase of tumor cell apoptosis by CD8+ T cells and its suppression by pre-culture with TAMs or MDSCs. This functional assay is useful for investigating CD8+ T cell suppression mechanisms by regulatory myeloid cells and identifying druggable targets to overcome it via high throughput screening.

Real Time Detection of In Vitro Tumor Cell Apoptosis Induced by CD8+ T Cells to Study Immune Suppressive Functions of Tumor-infiltrating Myeloid Cells

We describe here a protocol to investigate cytotoxicity of pre-activated CD8+ T cells against cancer cells by detecting apoptotic cancer cells via real-time microscopy. This protocol can investigate mechanisms behind myeloid cell-induced T cell suppression and evaluate compounds aimed at replenishing T cells via blockade of immune suppressive myeloid cells.

Potentiation of the tumor-killing ability of CD8+ T cells in tumors, along with their efficient tumor infiltration, is a key element of successful ...

Intramucosal Inoculation of Squamous Cell Carcinoma Cells in Mice for Tumor Immune Profiling and Treatment Response Assessment

Head and neck squamous cell carcinoma (HNSCC) is a debilitating and deadly disease with a high prevalence of recurrence and treatment failure. To develop better therapeutic strategies, understanding tumor microenvironmental factors that contribute to the treatment resistance is important. A major impediment to understanding disease mechanisms and improving therapy has been a lack of murine cell lines that resemble the aggressive and metastatic nature of human HNSCCs. Furthermore, a majority of murine models employ subcutaneous implantations of tumors which lack important physiological features of the head and neck region, including high vascular density, extensive lymphatic vasculature, and resident mucosal flora. The purpose of this study is to develop and characterize an orthotopic model of HNSCC. We employ two genetically distinct murine cell lines and established tumors in the buccal mucosa of mice. We optimize collagenase-based tumor digestion methods for the optimal recovery of single cells from established tumors. The data presented here show that mice develop highly vascularized tumors that metastasize to regional lymph nodes. Single-cell multiparametric mass cytometry analysis shows the presence of diverse immune populations with myeloid cells representing the majority of all immune cells. The model proposed in this study has applications in cancer biology, tumor immunology, and preclinical development of novel therapeutics. The resemblance of the orthotopic model to clinical features of human disease will provide a tool for enhanced translation and improved patient outcomes.

Here we present a reproducible method for developing an orthotopic murine model of head and neck squamous cell carcinoma. Tumors demonstrate clinically relevant histopathological features of the disease, including necrosis, poor differentiation, nodal metastases, and immune infiltration. Tumor-bearing mice develop clinically relevant symptoms including dysphagia, jaw displacement, and weight loss.

Head and neck squamous cell carcinoma (HNSCC) is a debilitating and deadly disease with a high prevalence of recurrence and treatment failure. To develop ...

In Vitro Assay to Study Tumor-macrophage Interaction

Tumor associated macrophages (TAMs) account for a large percentage of cells in the tumor mass for different types of cancers. Glioblastoma (GBM), a malignant brain tumor with no cure, has up to a half the tumor mass TAMs. TAMs can be pro-tumoral or anti-tumoral, depending on the activation of specific genes in the cells. Genetic mutations in the tumors, through regulating cytokine expression, can affect recruitment of TAMs to the tumor microenvironment. Here, we describe a quantitative cell-based assay to assess macrophage recruitment by the conditioned medium from the tumor cells. This assay uses the human macrophage cell line MV-4-11 to study macrophage attraction by the conditioned medium from glioblastoma, allowing for high reproducibility and low variability. Data generated with this assay can contribute to a better understanding of the interaction between the tumor and the tumor microenvironment. Similar assay can be used to assess interaction between the tumor cells and other immune cells, including T cells and natural killer (NK) cells.

This article represents a useful in vitro assay to evaluate the capability of conditioned medium from tumor cells to attract macrophages.

Tumor associated macrophages (TAMs) account for a large percentage of cells in the tumor mass for different types of cancers. Glioblastoma (GBM), a ...

In Vitro Evaluation of Oncogenic Transformation in Human Mammary Epithelial Cells

Tumorigenesis is a multi-step process in which cells acquire capabilities&#160;that allow their growth, survival, and dissemination under hostile conditions. Different tests seek to identify and quantify these hallmarks of cancerous cells; however, they often focus on a single aspect of cellular transformation and, in fact, multiple tests are required for their proper characterization. The purpose of this work is to provide researchers with a set of tools to assess cellular transformation in vitro from a broad perspective, thereby making it possible to draw sound conclusions.
A sustained proliferative signaling activation is the major feature of tumoral tissues and can be easily monitored under in vitro conditions by calculating the number of population doublings achieved over time. Besides, the growth of cells in 3D cultures allows their interaction with surrounding cells, resembling what occurs in vivo. This enables the evaluation of cellular aggregation and, together with immunofluorescent labeling of distinctive cellular markers, to obtain information on another relevant feature of tumoral transformation: the loss of proper organization. Another remarkable characteristic of transformed cells is their capacity to grow without attachment to other cells and to the extracellular matrix, which can be evaluated with the anchorage assay.
Detailed experimental procedures to evaluate cell growth rate, to perform immunofluorescent labeling of cell lineage markers in 3D cultures, and to test anchorage-independent cell growth in soft agar are provided. These methodologies are optimized for Breast Primary Epithelial Cells (BPEC) due to its relevance in breast cancer; however, procedures can be applied to other cell types after some adjustments.

This protocol provides experimental in vitro tools to evaluate the transformation of human mammary cells. Detailed steps to follow-up cell proliferation rate, anchorage-independent growth capacity, and distribution of cell lineages in 3D cultures with basement membrane matrix are described.

Tumorigenesis is a multi-step process in which cells acquire capabilities&#160;that allow their growth, survival, and dissemination under hostile ...

Chemical Conjugation of a Purified DEC-205-Directed Antibody with Full-Length Protein for Targeting Mouse Dendritic Cells In Vitro and In Vivo

Targeted antigen delivery to cross-presenting dendritic cells (DC) in vivo efficiently induces T effector cell responses and displays a valuable approach in&#160;vaccine design. Antigen is delivered to DC via antibodies specific for endocytosis receptors such as DEC-205 that induce uptake, processing, and MHC class I- and II-presentation.
Efficient and reliable conjugation of the desired antigen to a suitable antibody is a critical step in DC targeting and among other factors depends on the format of the antigen. Chemical conjugation of&#160;full-length protein to purified antibodies is one possible strategy. In the past, we have successfully established cross-linking of the model antigen ovalbumin (OVA) and a DEC-205-specific IgG2a antibody (&#945;DEC-205)&#160;for in vivo DC targeting studies in mice. The first step of the protocol is the purification of the antibody from the supernatant of the NLDC (non-lymphoid dendritic cells)-145 hybridoma by affinity chromatography. The purified antibody is activated for chemical conjugation by sulfo-SMCC (sulfosuccinimidyl 4-[N-maleimidomethyl] cyclohexane-1-carboxylate) while at the same time the sulfhydryl-groups of the OVA protein are exposed through incubation with TCEP-HCl (tris (2-carboxyethyl) phosphine hydrochloride). Excess TCEP-HCl and sulfo-SMCC are removed and the antigen is mixed with the activated antibody for overnight coupling. The resulting &#945;DEC-205/OVA conjugate is concentrated and freed from unbound OVA. Successful conjugation of OVA to &#945;DEC-205 is verified by western blot analysis and enzyme-linked immunosorbent assay (ELISA).
We have successfully used chemically crosslinked &#945;DEC-205/OVA to induce cytotoxic T cell responses in the liver and to compare different adjuvants for their potential in inducing humoral and cellular immunity following in vivo targeting of DEC-205+ DC. Beyond that, such chemically coupled antibody/antigen conjugates offer valuable tools for the efficient induction of vaccine responses to tumor antigens and have been proven to be superior to classical immunization approaches regarding the prevention and therapy of various types of tumors.

Chemical Conjugation of a Purified DEC-205-Directed Antibody with Full-Length Protein for Targeting Mouse Dendritic Cells In Vitro and In Vivo

We describe a protocol for the chemical conjugation of the model antigen ovalbumin to an endocytosis receptor-specific antibody for in vivo dendritic cell targeting. The protocol includes purification of the antibody, chemical conjugation of the antigen, as well as purification of the conjugate and the verification of efficient conjugation.

Targeted antigen delivery to cross-presenting dendritic cells (DC) in vivo efficiently induces T effector cell responses and displays a valuable approach ...