Name: analyzing tumor and tissue distribution of target antigen specific therapeutic antibody
Uploaded: 2020-05-16T12:30:00
Description: Watch this Scientific Journal Video about Analyzing Tumor and Tissue Distribution of Target Antigen Specific Therapeutic Antibody at JoVE.com

We are thankful to University of Virginia Cancer Center Core Imaging Facility, Biomolecular Analysis Facility, Advanced Microscopy Facility and the Core Vivarium Facility for Assistance. J. T-S is an early career investigator of Ovarian Cancer Academy (OCA-DoD). This work was supported by NCI/NIH grant (R01CA233752) to J. T-S, U.S. DoD Breast Cancer Research Program (BCRP) breakthrough level-1 award to J. T-S (BC17097) and U.S. DoD Ovarian Cancer Research Program (OCRP) funding award (OC180412) to J. T-S

All the procedures involving animals handling and tumor xenografts studies were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) here at the University of Virginia and conform to the relevant regulatory standards
1. Expression and purification of antibodies
<ol>
	<li>Maintenance of CHO cells
	<ol>
		<li>Grow CHO cells in FreeStyle CHO Media supplemented with commercially available 1x glutamine supplement at 37 &#730;C shaking at 130 rpm with 5% CO2 ...

<ol>
	<li>Takahashi, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Muromonab+CD3+(Orthoclone+OKT3).">Muromonab CD3 (Orthoclone OKT3).</a> Journal of Toxicological Sciences. 20, 483-484 (1995).</li><li>Tushir-Singh, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibody-siRNA+conjugates:+drugging+the+undruggable+for+anti-leukemic+therapy.">Antibody-siRNA conjugates: drugging the undruggable for anti-leukemic therapy.</a> Expert Opinion in Biological Therapy. 17, 325-338 (2017).</li><li>Gravitz, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+immunotherapy.">Cancer immunotherapy.</a> Nature. 504, 1 (2013).</li><li>Pagel, J. M., West, H. 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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=Folate+receptor-alpha+(FOLR1)+expression+and+function+in+triple+negative+tumors.">Folate receptor-alpha (FOLR1) expression and function in triple negative tumors.</a> PLoS One. 10, 0122209 (2015).</li><li>Lin, J., 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+antitumor+activity+of+the+human+FOLR1-specific+monoclonal+antibody,+farletuzumab,+in+an+ovarian+cancer+mouse+model+is+mediated+by+antibody-dependent+cellular+cytotoxicity.">The antitumor activity of the human FOLR1-specific monoclonal antibody, farletuzumab, in an ovarian cancer mouse model is mediated by antibody-dependent cellular cytotoxicity.</a> Cancer Biology Therapy. 14, 1032-1038 (2013).</li><li>Chen, Y., Kim, M. T., Zheng, L., Deperalta, G., Jacobson, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+Characterization+of+Cross-Linked+Species+in+Trastuzumab+Emtansine+(Kadcyla).">Structural Characterization of Cross-Linked Species in Trastuzumab Emtansine (Kadcyla).</a> Bioconjugate Chemistry. 27, 2037-2047 (2016).</li><li>Bauerschlag, D. 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V., 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=HER2+expression+identifies+dynamic+functional+states+within+circulating+breast+cancer+cells.">HER2 expression identifies dynamic functional states within circulating breast cancer cells.</a> Nature. 537, 102-106 (2016).</li><li>Fakih, M., Vincent, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adverse+events+associated+with+anti-EGFR+therapies+for+the+treatment+of+metastatic+colorectal+cancer.">Adverse events associated with anti-EGFR therapies for the treatment of metastatic colorectal cancer.</a> Current Oncology. 17, 18-30 (2010).</li><li>Koba, W., Jelicks, L. A., Fine, E. 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Selective and tumor tissue specific delivery of anti-cancer therapeutic agent is the key to measure efficacy and safety of a given targeted therapy13. Here we have described a quick and efficient approach to investigate the detailed tissue and tumor distribution of clinical, farletuzumab and a nonclinical BaCa antibody. The described approach is applicable to any newly generated antibody and can be used alongside of a clinically effective antibody (with desired qualities) for its tumor/organ distr...

FDA approved the first monoclonal antibody targeting CD3 (OKT3, Muromonab) in 19861,2. Since then for the next twenty years, there has been a rapid explosion in the field of antibody engineering due to the overwhelming success of antibodies against immune checkpoint inhibitors3. Beside indirect activation of immune system, antibodies are being aimed to directly flag cancer cells to precisely engage immune effector cells, trigger cytotoxicity via death receptor agonist, block tumor cell survival signaling, obstruct angiogenesis (growth of blood vessels), constrain immune checkpoint regulators, deliver radioisotopes, chemotherapy drugs and siRNA as a conjugated agents2. In addition, studying the single chain variable fragments (scFv) of various antibodies on the surface of patient derived T-cells and NK cells (CAR-T and CAR-NK) is a fast growing area of clinical investigations for cell-based therapies4.
The ultra-high affinity of antibody-based drugs that provides selectivity to antigen expressing tumor cells makes it an attractive agent. Likewise, the targeted delivery and tumor retention of a therapeutic antibody (or a chemical drug) is the key to balance efficacy over toxicity. Therefore, a large number of protein engineering based strategies that include but are not limited to bispecific5 and tri-specific antibodies6 are being exploited to significantly enhance avidity optimized tumor retention of intravenously (IV) injected therapeutics5,7. Here, we describe a simple fluorescence-based method to address the tumor and tissue distribution of potentially effective anti-cancer antibodies.
Because animal tissues possess auto-fluorescence when excited in visible spectrum, the antibodies were initially labeled with near Infrared dye (e.g., IRDye 800CW). For proofs of concept investigations, we have made use of folate receptor alpha-1 (FOLR1) targeting antibody called farletuzumab and its derivative called Bispecific anchor Cytotoxicity activator (BaCa)7 antibody that co-targets FOLR1 and death receptor-5 (DR5)8 in one recombinant antibody. FOLR1 is a well-defined overexpressed target receptor in ovarian and TNBC cancer cells, tumor xenografts and patient tumors9. Notably, there are multiple efforts to clinically exploit FOLR1 using antibody-based approaches to engage immune effector cells and antibody drug conjugates (ADC) for ovarian and breast cancers10,11.
In this methods paper, we cloned, expressed and purified clinical anti-FOLR1 (farletuzumab) along with other control antibodies using CHO expression system. IgG1 isotype and a clinical anti-idiotype mucin-16 antibody called abagovomab12 were used as negative controls. Following protein-A purification, indicated antibodies were labeled with IRDye 800CW and were administered into the tail vein of nude mice either bearing ovarian tumor xenografts or stably transfected human FOLR1 expressing murine colon cancer xenografts. The antibody localization was tracked by live imaging using in vivo imaging spectrum at multiple different time points7. This method does not require any genetic modification or injection of the substrate to enable light emission and is significantly quicker, cost effective and efficient. The general cloning, expression, purification and labeling protocol described below can be applied to any clinical and nonclinical antibody if heavy and light chain sequences are available.

<table>
	<tbody>
		<tr>
			<td>FreeStyle CHO media</td>
			<td>Gibco Life Technologies</td>
			<td>Cat # 12651-014</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Anti (100X)</td>
			<td>Gibco Life Technologies</td>
			<td>Cat # 15240-062</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Clumping Agent</td>
			<td>Gibco Life Technologies</td>
			<td>Cat # 01-0057DG</td>
			<td></td>
		</tr>
		<tr>
			<td>BD Insulin Syringe</td>
			<td>BD BioSciences</td>
			<td>Cat #329420</td>
			<td></td>
		</tr>
		<tr>
			<td>Caliper IVIS Spectrum</td>
			<td>PerkinElmer</td>
			<td>Cat #124262</td>
			<td></td>
		</tr>
		<tr>
			<td>CHO CD EfficientFeed B</td>
			<td>Gibco Life Technologies</td>
			<td>Cat #A10240-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning 500 mL DMEM (Dulbecco&#39;s Modified Eagle&#39;s Medium)</td>
			<td>Corning</td>
			<td>Cat # 10-13-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning 500 mL RPMI 1640</td>
			<td>Corning</td>
			<td>Cat # 10-040-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Cy5 conjugated Anti-Human IgG (H+L)</td>
			<td>Jackson ImmunoResearch</td>
			<td>Cat # 709-175-149</td>
			<td></td>
		</tr>
		<tr>
			<td>GlutaMax-I (100X)</td>
			<td>Gibco Life Technologies</td>
			<td>Cat # 35050-061</td>
			<td></td>
		</tr>
		<tr>
			<td>HiPure Plasmid Maxiprep kit</td>
			<td>Invitrogen</td>
			<td>Cat # K21007</td>
			<td></td>
		</tr>
		<tr>
			<td>HiTrap MabSelect SuRe Column</td>
			<td>GE Healthcare</td>
			<td>Cat # 11-0034-93</td>
			<td></td>
		</tr>
		<tr>
			<td>Infusion</td>
			<td>Takara BioScience</td>
			<td>STO344</td>
			<td></td>
		</tr>
		<tr>
			<td>IRDye 800CW NHS Ester</td>
			<td>LI-COR</td>
			<td>Cat # 929-70020</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane, USP</td>
			<td>Covetrus</td>
			<td>Cat # 11695-6777-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Lubricant Eye Ointment</td>
			<td>Refresh Lacri-Lube</td>
			<td>Cat #4089</td>
			<td></td>
		</tr>
		<tr>
			<td>Matrigel</td>
			<td>Corning</td>
			<td>Cat # 354234</td>
			<td></td>
		</tr>
		<tr>
			<td>PEI transfection reagent</td>
			<td>Thermo Fisher</td>
			<td>Cat # BMS1003A</td>
			<td></td>
		</tr>
		<tr>
			<td>Slide-A-Lyzer Dialysis Cassettes</td>
			<td>Thermo Scientific</td>
			<td>Cat # 66333</td>
			<td></td>
		</tr>
		<tr>
			<td>Steritop Vacuum Filters</td>
			<td>Millipore Express</td>
			<td>Cat #S2GPT02RE</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Gibco Life Technologies</td>
			<td>Cat # 15400-054</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Experimental Models: Cell lines</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Human: OVCAR-3</td>
			<td>American Type Culture Collection</td>
			<td>ATCC HTB-161</td>
			<td></td>
		</tr>
		<tr>
			<td>Human: CHO-K cells</td>
			<td>Stable transformed in our lab</td>
			<td>ATCC CCL-61</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse: 4T1</td>
			<td>Kind gift from Dr. Chip Landen, UVA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse: MC38</td>
			<td>Kind gift from Dr. Suzanne Ostrand-Rosenberg, UMBC</td>
			<td>Authenticated by STR profiling</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse: MC38 hFOLR1</td>
			<td>Generated in our laboratory (This paper)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Experimental Models: Animal</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Mice: athymic Nude Foxn1nu/Foxn1+</td>
			<td>Envigo</td>
			<td>Multiple Orders</td>
			<td></td>
		</tr>
		<tr>
			<td>Mice: NOD.Cg Prkdcscid Il2rgtm1Wjl/SzJ</td>
			<td>Jackson Laboratory</td>
			<td>Multiple Orders</td>
			<td></td>
		</tr>
	</tbody>
</table>

analyzing tumor and tissue distribution of target antigen specific therapeutic antibody

Monoclonal antibodies are high affinity multifunctional drugs that work by variable independent mechanisms to eliminate cancer cells. Over the last few decades, the field of antibody-drug conjugates, bispecific antibodies, chimeric antigen receptors (CAR) and cancer immunotherapy has emerged as the most promising area of basic and therapeutic investigations. With numerous successful human trials targeting immune checkpoint receptors and CAR-T cells in leukemia and melanoma at a breakthrough pace, it is highly exciting times for oncologic therapeutics derived from variations of antibody engineering. Regrettably, a significantly large numbers of antibody and CAR based therapeutics have also proven disappointing in human trials of solid cancers because of the limited availability of immune effector cells in the tumor bed. Importantly, nonspecific distribution of therapeutic antibodies in tissues other than tumors also contribute to the lack of clinical efficacy, associated toxicity and clinical failure. As faithful translation of preclinical studies into human clinical trails are highly relied on mice tumor xenograft efficacy and safety studies, here we highlight a method to test the tumor and general tissue distribution of therapeutic antibodies. This is achieved by labeling the protein-A purified antibody with near Infrared fluorescent dye followed by live imaging of tumor bearing mice.

In the described methodology, first we cloned antibodies targeting folate receptor alpha-1 (FOLR1) named farletuzumab, and a bispecific antibody called BaCa consisting of farletuzumab and lexatumumab along with control antibodies such as abagovomab (sequences provided in Supplementary File 1). Details of representative variable heavy (VH) and variable light (VL) domains in DNA clones (pVH, pVL) are shown in Figure 1A. To confirm the positive clones, we carried out colony PCR...

Watch this Scientific Journal Video about Analyzing Tumor and Tissue Distribution of Target Antigen Specific Therapeutic Antibody at JoVE.com

Analyzing Tumor and Tissue Distribution of Target Antigen Specific Therapeutic Antibody

Here we present a protocol to study the in vivo localization of antibodies in mice tumor xenograft models.

Monoclonal antibodies are high affinity multifunctional drugs that work by variable independent mechanisms to eliminate cancer cells. Over the last few ...

This protocol demonstrates the expression and purification of antibodies and real time monitoring of antibody distribution in tumor and tissue. Screening antibodies with described protocol will help select antibodies that have limited non-specific tissue distribution, and enrich tumor localizations. The described technique is quick and cost-effective.Other techniques, such as single-photon emission computed tomography and positron emission tomography, are very expensive and require radioactive and other sophisticated tracers. The technique is not limited to cancer targeting antibodies. It can be applied to any other disease, such as lung or heart diseases, for the analysis of antibody distribution in the body.Demonstrating the procedure, will be Jeremy Gatesman, a veterinary technician from my university. Raw CHO cells in 200 milliliters of media, in Delong, Erlenmeyer baffled flasks. Combine five milliliters of CHO freestyle media with 50 micrograms of variable heavy clone DNA, and 75 micrograms a variable light clone DNA in a 15 milliliter tube.Then, vortex the tube. Leave the mixture at room temperature for five minutes. Add 750 microliters of one milligram per milliliter polyethylenimine stock to the DNA solution, and aggressively vortex it for 30 seconds.Leave the mixture at room temperature for an additional five minutes. Add the entire mixture to the CHO cells while manually shaking the flask. Immediately incubate the cells at 37 degrees Celsius while shaking at 130 RPM.On the next day, add two milliliters of 100 X anti-clumping agent, and two milliliters of 100 X antibacterial antimycotic solution to the cells. Incubate the flasks at 32 to 34 degrees Celsius, with shaking at 130 RPM. Continue culturing the cells for 10 to 11 days, adding 10 milliliters of Tryptone N1 feed, and two milliliters of 100 X glutamine supplement on every fifth day.Count the cells on every third day to ensure that cell viability remains above 80%On day 10 or 11, harvest the medium for antibody purification by centrifuging the culture at 3000 times G, and four degrees Celsius for 40 to 60 minutes. Then, filter the clear media with a 0.22 micrometer bottle filter. To purify the antibodies, equilibrate the protein A column with two column volumes of binding buffer.Pass the filtered media through the column at the flow rate of one milliliter per minute. Then wash the column with two column volumes of binding buffer. Use five milliliters of elution buffer to elute the antibody into 500 microliter fractions.And neutralize the pH of the alluded antibody by adding 10 microliters of neutralization buffer for fraction. Measure the concentration of the purified antibody with a spectrophotometer using the default protocol for IgG. Dialyze 0.5 milliliters of the antibody using a dialysis cassette in one liter of conjugation buffer.After four hours, transfer the dialysis cassette to fresh buffer and dialyze overnight. To set up a conjugation reaction, add 0.03 micrograms of IRR dye 800 CWU per one milligram of antibody in a total volume of 500 microliters. Incubate the mixture for two hours at 20 degrees Celsius, then purify the labeled conjugates by extensive dialysis against PBS.Estimate the degree of labeling by measuring the absorbance of the dye 780 nanometers, and absorbance of the protein at 280 nanometers. To develop mouse xenographs, gently lift the skin of the animal and separate it from the underlying muscle layer. Slowly inject 100 microliters of cell suspension under the skin with a 26 gauge needle.Wait for a few seconds before taking the needle out so that basement matrix medium inform the semi-solid gel-like structure along with cells under the skin, which will prevent the mixture from coming out of the injection site. To perform in vivo imaging, inject the dye labeled antibody via the tail vein. After anesthetizing the mouse, check for the lack of response to pedal reflexes, and dilate the vein by applying warm water.Use a 1cc insulin syringe with a 26 gauge needle to inject 25 micrograms of the labeled antibody in a volume of 100 microliters. As a negative control, label and inject the non-specific IgG isotype antibody which does not target cancer cells. Perform in vivo imaging eight, 24 and 48 hours after antibody injections.In the imaging software, click initialize. Confirm that the stage temperature is 37 degrees Celsius. In the control panel, set up fluorescence imaging through the imaging wizard, and set the excitation to 773 nanometers, emission to 792 nanometers.Transfer the anesthetized mouse into the imaging chamber. Position it on the imaging field using the nose cone. When ready, click acquire on the control panel for the image acquisition, and click auto expose.The generated image is the overlay of the fluorescence on the photographic image with optical fluorescence and density displayed in units of counts or photons. Positive cDNA clones with variable heavy and variable light domains were confirmed with colony PCR. Representative results of purified farletuzumab run on non-reducing and reducing SDS page are shown here.Heavy and light chains produced 50 and 25 kilodalton bands after reduction. Binding of antibodies to native proteins in the cell surface was also confirmed. Fluorescently labeled antibodies were tail vein injected, into mice grafted with full R1 expressing tumors.Animals were lived image at multiple time points using IVIS. the data confirs selective enrichment of full R1 and BaCa antibodies into the tumors. When attempting this protocol, keep in mind that held maintenance of CHO cells is critical for antibody yield.And it is important to have a similar degree of fluorescent dye conjugation for competitive tumor localization. Following this procedure, other methods such as tissue immunohistochemistry and tissue or tumor specific ELISA can be performed to support the live mice imaging data.

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Research

JoVE Journal

Cancer Research

Target Cell Pre-enrichment and Whole Genome Amplification for Single Cell Downstream Characterization

Rare target cells can be isolated from a high background of non-target cells using antibodies specific for surface proteins of target cells. A recently developed method uses a medical wire functionalized with anti-epithelial cell adhesion molecule (EpCAM) antibodies for in vivo isolation of circulating tumor cells (CTCs)1. A patient-matched cohort in non-metastatic prostate cancer showed that the in vivo isolation technique resulted in a higher percentage of patients positive for CTCs as well as higher CTC counts as compared to the current gold standard in CTC enumeration. As cells cannot be recovered from current medical devices, a new functionalized wire (referred to as Device) was manufactured allowing capture and subsequent detachment of cells by enzymatic treatment. Cells are allowed to attach to the Device, visualized on a microscope and detached using enzymatic treatment. Recovered cells are cytocentrifuged onto membrane-coated slides and harvested individually by means of laser microdissection or micromanipulation. Single-cell samples are then subjected to single-cell whole genome amplification allowing multiple downstream analysis including screening and target-specific approaches. The procedure of isolation and recovery yields high quality DNA from single cells and does not impair subsequent whole genome amplification (WGA). A single cell&#39;s amplified DNA can be forwarded to screening and/or targeted analysis such as array comparative genome hybridization (array-CGH) or sequencing. The device allows ex vivo isolation from artificial rare cell samples (i.e. 500 target cells spiked into 5 mL of peripheral blood). Whereas detachment rates of cells are acceptable (50 - 90%), the recovery rate of detached cells onto slides spans a wide range dependent on the cell line used (&#60;10 - &#62;50%) and needs some further attention. This device is not cleared for the use in patients.

This protocol is to recover and prepare rare target cells from a mixture with non-target background cells for molecular genetic characterization at the single-cell level. DNA quality is equal to non-treated single cells and allows for single-cell application (both screening based and targeted analysis).

Rare target cells can be isolated from a high background of non-target cells using antibodies specific for surface proteins of target cells. A recently ...

A Three-dimensional Thymic Culture System to Generate Murine Induced Pluripotent Stem Cell-derived Tumor Antigen-specific Thymic Emigrants

The inheritance of pre-rearranged T cell receptors (TCRs) and their epigenetic rejuvenation make induced pluripotent stem cell (iPSC)-derived T cells a promising source for adoptive T cell therapy (ACT). However, classical in vitro methods for producing regenerated T cells from iPSC result in either innate-like or terminally differentiated T cells, which are phenotypically and functionally distinct from na&#239;ve T cells. Recently, a novel three-dimensional (3D) thymic culture system was developed to generate a homogenous subset of CD8&#945;&#946;+ antigen-specific T cells with a na&#239;ve T cell-like functional phenotype, including the capacity for proliferation, memory formation, and tumor suppression in vivo. This protocol avoids aberrant developmental fates, allowing for the generation of clinically relevant iPSC-derived T cells, designated as iPSC-derived thymic emigrants (iTE), while also providing a potent tool to elucidate the subsequent functions necessary for T cell maturation after thymic selection.

This article describes a novel method to generate tumor antigen-specific induced pluripotent stem cell-derived thymic emigrants (iTE) by a three-dimensional (3D) thymic culture system. iTE are a homogenous subset of T cells closely related to na&#239;ve T cells with the capacity for proliferation, memory formation, and tumor suppression.

The inheritance of pre-rearranged T cell receptors (TCRs) and their epigenetic rejuvenation make induced pluripotent stem cell (iPSC)-derived T cells a ...

In Vitro Tumor Cell Rechallenge For Predictive Evaluation of Chimeric Antigen Receptor T Cell Antitumor Function

The field of chimeric antigen receptor (CAR) T cell therapy is rapidly advancing with improvements in CAR design, gene-engineering approaches and manufacturing optimizations. One challenge for these development efforts, however, has been the establishment of in vitro assays that can robustly inform selection of the optimal CAR T cell products for in vivo therapeutic success. Standard in vitro tumor-lysis assays often fail to reflect the true antitumor potential of the CAR T cells due to the relatively short co-culture time and high T cell to tumor ratio. Here, we describe an in vitro co-culture method to evaluate CAR T cell recursive killing potential at high tumor cell loads. In this assay, long-term cytotoxic function and proliferative capacity of CAR T cells is examined in vitro over 7 days with additional tumor targets administered to the co-culture every other day. This assay can be coupled with profiling T cell activation, exhaustion and memory phenotypes. Using this assay, we have successfully distinguished the functional and phenotypic differences between CD4+ and CD8+ CAR T cells against glioblastoma (GBM) cells, reflecting their differential in vivo antitumor activity in orthotopic xenograft models. This method provides a facile approach to assess CAR T cell potency and to elucidate the functional variations across different CAR T cell products.

Here, we describe an in vitro co-culture method to recursively challenge tumor-targeted T cells, which allows for phenotypic and functional analysis of antitumor T cell activity.

The field of chimeric antigen receptor (CAR) T cell therapy is rapidly advancing with improvements in CAR design, gene-engineering approaches and ...

In Vivo Immunofluorescence Localization for Assessment of Therapeutic and Diagnostic Antibody Biodistribution in Cancer Research

Monoclonal antibodies (mAbs) are important tools in cancer detection, diagnosis, and treatment. They are used to unravel the role of proteins in tumorigenesis, can be directed to cancer biomarkers enabling tumor detection and characterization, and can be used for cancer therapy as mAbs or antibody-drug conjugates to activate immune effector cells, to inhibit signaling pathways, or directly kill cells carrying the specific antigen. Despite clinical advancements in the development and production of novel and highly specific mAbs, diagnostic and therapeutic applications can be impaired by the complexity and heterogeneity of the tumor microenvironment. Thus, for the development of efficient antibody-based therapies and diagnostics, it is crucial to assess the biodistribution and interaction of the antibody-based conjugate with the living tumor microenvironment. Here, we describe In Vivo Immunofluorescence Localization (IVIL) as a new approach to study interactions of antibody-based therapeutics and diagnostics in the in vivo physiological and pathological conditions. In this technique, a therapeutic or diagnostic antigen-specific antibody is intravenously injected in&#160;vivo and localized ex vivo with a secondary antibody in isolated tumors. IVIL, therefore, reflects the in vivo biodistribution of antibody-based drugs and targeting agents. Two IVIL applications are described assessing the biodistribution and accessibility of antibody-based contrast agents for molecular imaging of breast cancer. This protocol will allow future users to adapt the IVIL method for their own antibody-based research applications.

The in vivo immunofluorescence localization (IVIL) method can be used to examine in vivo biodistribution of antibodies and antibody conjugates for oncological purposes in living organisms using a combination of in vivo tumor targeting and ex vivo immunostaining methods.

Monoclonal antibodies (mAbs) are important tools in cancer detection, diagnosis, and treatment. They are used to unravel the role of proteins in ...

Using Human Induced Pluripotent Stem Cells for the Generation of Tumor Antigen-specific T Cells

The generation and expansion of functional T cells in vitro can lead to a broad range of clinical applications. One such use is for the treatment of patients with advanced cancer. Adoptive T cell transfer (ACT) of highly enriched tumor antigen-specific T cells has been shown to cause durable regression of metastatic cancer in some patients. However, during expansion, these cells may become exhausted or senescent, limiting their effector function and persistence in vivo. Induced pluripotent stem cell (iPSC) technology may overcome these obstacles by leading to in vitro generation of large numbers of less differentiated tumor antigen-specific T cells. Human iPSC (hiPSC) have the capacity to differentiate into any type of somatic cell, including lymphocytes, which retain the original T cell receptor (TCR) genomic rearrangement when a T cell is used as a starting cell. Therefore, reprogramming of human tumor antigen-specific T cells to hiPSC followed by redifferentiation to T cell lineage has the potential to produce rejuvenated tumor antigen-specific T cells. Described here is a method for generating tumor antigen-specific CD8&#945;&#946;+ single positive (SP) T cells from hiPSC using OP9/DLL1 co-culture system. This method is a powerful tool for in vitro T cell lineage generation and will facilitate the development of in vitro derived T cells for use in regenerative medicine and cell-based therapies.

This article describes a method to generate functional tumor antigen-specific induced pluripotent stem cell-derived CD8&#945;&#946;+ single positive T cells using OP9/DLL1 co-culture system.

The generation and expansion of functional T cells in vitro can lead to a broad range of clinical applications. One such use is for the treatment of ...

Analyzing Tumor Gene Expression Factors with the CorExplorer Web Portal

Differential gene expression analysis is an important technique for understanding disease states. The machine learning algorithm CorEx has shown utility in analyzing differential expression of groups of genes in tumor RNA-seq in a way that may be helpful for advancing precision oncology. However, CorEx produces many factors that can be challenging to analyze and connect to existing understanding. To facilitate such connections, we have built a website, CorExplorer, that allows users to interactively explore the data and answer common questions related to its analysis. We trained CorEx on RNA-seq gene expression data for four tumor types: ovarian, lung, melanoma, and colorectal. We then incorporated corresponding survival, protein-protein interactions, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments, and heatmaps into the website for association with the factor graph visualization. Here we employ example protocols to illustrate use of the database for comprehending the significance of the learned tumor factors in the context of this external data.

We introduce the CorExplorer web portal, an resource for exploration of tumor RNA sequencing factors found by the machine learning algorithm CorEx (Correlation Explanation), and show how factors can be analyzed relative to survival, database annotations, protein-protein interactions, and one another to gain insight into tumor biology and therapeutic interventions.

Differential gene expression analysis is an important technique for understanding disease states. The machine learning algorithm CorEx has shown utility ...

Measuring Real-time Drug Response in Organotypic Tumor Tissue Slices

Tumor tissues are composed of cancerous cells, infiltrated immune cells, endothelial cells, fibroblasts, and extracellular matrix. This complex milieu constitutes the tumor microenvironment (TME) and can modulate response to therapy in vivo or drug response ex vivo. Conventional cancer drug discovery screens are carried out on cells cultured in a monolayer, a system critically lacking the influence of TME. Thus, experimental systems that integrate sensitive and high-throughput assays with physiological TME will strengthen the preclinical drug discovery process. Here, we introduce ex vivo tumor tissue slice culture as a platform for medium-high-throughput drug screening. Organotypic tissue slice culture constitutes precisely-cut, thin tumor sections that are maintained with the support of a porous membrane in a liquid-air interface. In this protocol, we describe the preparation and maintenance of tissue slices prepared from mouse tumors and tumors from patient-derived xenograft (PDX) models. To assess changes in tissue viability in response to drug treatment, we leveraged a biocompatible luminescence-based viability assay that enables real-time, rapid, and sensitive measurement of viable cells in the tissue. Using this platform, we evaluated dose-dependent responses of tissue slices to the multi-kinase inhibitor, staurosporine, and cytotoxic agent, doxorubicin. Further, we demonstrate the application of tissue slices for ex vivo pharmacology by screening 17 clinical and preclinical drugs on tissue slices prepared from a single PDX tumor. Our physiologically-relevant, highly-sensitive, and robust ex vivo screening platform will greatly strengthen preclinical oncology drug discovery and treatment decision making.&#160;

We introduce a protocol for measuring real-time drug response in organotypic tumor tissue slices. The experimental strategy outlined here provides a platform to carry out medium-high throughput drug screens on tissue slices derived from clinical or mouse tumors in ex vivo conditions.

Tumor tissues are composed of cancerous cells, infiltrated immune cells, endothelial cells, fibroblasts, and extracellular matrix. This complex milieu ...

An Ex Vivo Brain Slice Model to Study and Target Breast Cancer Brain Metastatic Tumor Growth

Brain metastasis is a serious consequence of breast cancer for women as these tumors are difficult to treat and are associated with poor clinical outcomes. Preclinical mouse models of breast cancer brain metastatic (BCBM) growth are useful but are expensive, and it is difficult to track live cells and tumor cell invasion within the brain parenchyma. Presented here is a protocol for ex vivo brain slice cultures from xenografted mice containing intracranially injected breast cancer brain-seeking clonal sublines. MDA-MB-231BR luciferase tagged cells were injected intracranially into the brains of Nu/Nu female mice, and following tumor formation, the brains were isolated, sliced, and cultured ex vivo. The tumor slices were imaged to identify tumor cells expressing luciferase and monitor their proliferation and invasion in the brain parenchyma for up to 10 days. Further, the protocol describes the use of time-lapse microscopy to image the growth and invasive behavior of the tumor cells following treatment with ionizing radiation or chemotherapy. The response of tumor cells to treatments can be visualized by live-imaging microscopy, measuring bioluminescence intensity, and performing histology on the brain slice containing BCBM cells. Thus, this ex vivo slice model may be a useful platform for rapid testing of novel therapeutic agents alone or in combination with radiation to identify drugs personalized to target an individual patient&#39;s breast cancer brain metastatic growth within the brain microenvironment.

An Ex Vivo Brain Slice Model to Study and Target Breast Cancer Brain Metastatic Tumor Growth

We introduce a protocol for measuring real-time drug and radiation response of breast cancer brain metastatic cells in an organotypic brain slice model. The methods provide a quantitative assay to investigate the therapeutic effects of various treatments on brain metastases from breast cancer in an ex vivo manner within the brain microenvironment interface.

Brain metastasis is a serious consequence of breast cancer for women as these tumors are difficult to treat and are associated with poor clinical ...

Pancreatic Cancer-Derived Tumor Organoids and Fibroblasts from Fresh Tissue

Establishment of Pancreatic Cancer-Derived Tumor Organoids and Fibroblasts From Fresh Tissue

Tumor organoids are three-dimensional (3D) ex vivo tumor models that recapitulate the biological key features of the original primary tumor tissues. Patient-derived tumor organoids have been used in translational cancer research and can be applied to assess treatment sensitivity and resistance, cell-cell interactions, and tumor cell interactions with the tumor microenvironment. Tumor organoids are complex culture systems that require advanced cell culture techniques and culture media with specific growth factor cocktails and a biological basement membrane that mimics the extracellular environment. The ability to establish primary tumor cultures highly depends on the tissue of origin, the cellularity, and the clinical features of the tumor, such as the tumor grade. Furthermore, tissue sample collection, material quality and quantity, as well as correct biobanking and storage are crucial elements of this procedure. The technical capabilities of the laboratory are also crucial factors to consider. Here, we report a validated SOP/protocol that is technically and economically feasible for the culture of ex vivo tumor organoids from fresh tissue samples of pancreatic adenocarcinoma origin, either from fresh primary resected patient donor tissue or patient-derived xenografts (PDX). The technique described herein can be performed in laboratories with basic tissue culture and mouse facilities and is tailored for wide application in the translational oncology field.

Author Spotlight: Establishment of Pancreatic Cancer-Derived Tumor Organoids and Fibroblasts From Fresh Tissue  

Tumor organoids have revolutionized cancer research and the approach to personalized medicine. They represent a clinically relevant tumor model that allows researchers to stay one step ahead of the tumor in the clinic. This protocol establishes tumor organoids from fresh pancreatic tumor tissue samples and patient-derived xenografts of pancreatic adenocarcinoma origin.

Tumor organoids are three-dimensional (3D) ex vivo tumor models that recapitulate the biological key features of the original primary tumor tissues. ...

Fresh Primary Tumor Tissue Processing to Establish Tumor Organoids and Primary Fibroblasts

Begin by placing the tissue in a sterile tissue culture plate and removing excess media. Measure the tissue with a sterile metal ruler and photograph it. Add three milliliters of advanced DMEM/F-12 media to the cut tissue and pipette the tissue up and down to wash it.Then wash the tissue with three milliliters of PBS. Aspirate the medium from the tissue culture plate and cut it into small pieces using sterile blades and two milliliters of digestion media. Then collect the tissue into a 50-milliliter tube containing five milliliters total of the digestion medium.Incubate the tube at 37 degrees Celsius for one hour. Periodically mix the suspension by pipetting up and down. Inactivate the trypsin by adding five milliliters of advanced DMEM/F-12 to the tube.Then filter the sample through a 70-micrometer pore strainer to remove any large debris. Now pipette two milliliters of DMEM containing 10%FBS to the top of the filter, and use a pipette to collect the debris and tissue remnants for fibroblast culturing. Then plate the debris for fibroblast culture.Centrifuge the filtrate at room temperature at 200 to 300 G for five minutes, and then aspirate the supernatant. Add five milliliters of advanced DMF 12 to the pellet and centrifuge the suspension again at 300 G for five minutes. For red blood cell lysis, resuspend the pellet in four milliliters of ammonium chloride potassium lysis buffer, and transfer it to a 15-milliliter tube.Incubate the cells at room temperature for two minutes. After centrifuging the mixture at the same conditions as demonstrated previously, aspirate the supernatant. To the pellet, add five milliliters of advanced DMEM/F-12, and centrifuge again at four degrees Celsius.After aspirating the supernatant, add one milliliter of commercially available cell dissociation reagent to the pellet and incubate it for two to three minutes at room temperature. After incubation, centrifuge and aspirate the supernatant once again. Then resuspend the pellet in five milliliters of advanced DMEM/F-12.Dissociate cell clumps by pipetting the suspension multiple times with a P1000 pipette. Centrifuge the suspension and remove the supernatant. Next, obtain pre-chilled P1000 and P200 pipette tips, and use the cold tips fixed onto the P1000 pipette to resuspend the cell pellet in the membrane matrix, before placing the Falcon on ice to prevent solidification.Obtain the preheated plate from the incubator. Using the P200 pipette set at 48 microliters and using cold tips, create basement membrane matrix domes in the preheated plate. Then incubate it to solidify the basement membrane mix.Once the matrix is solidified, add two to two and a half milliliters of advanced DMEM/F-12, supplemented with the growth factors and inhibitors. Tumor cells were isolated and tumor organoids were established from fresh tissue over a 15-day period. Occasionally, large cell debris volumes prevent accurate visualization of developing tumor organoids.Developing organoids were observed to phenotypically vary from isolated, rounded to spheroid or aggregate-like cultures, depending on the tumor origin. Organoid cultures may be contaminated by fibroblasts, a common PI product of primary tumor cell culture. After approximately seven days of culture, the fibroblasts migrate from the basement membrane matrix domes and adhere to the cell plates, which may compromise optimal organoid growth.Fibroblast cultures are established from the tissue debris recovered from the filter. The cells migrate out of the tissue debris and adhere to the culture plates.