Name: assessment of chimeric antigen receptor t cell-associated toxicities using an acute lymphoblastic leukemia patient-derived xenograft mouse model
Uploaded: 2023-02-10T12:35:00
Description: Watch this Scientific Journal Video about Assessment of Chimeric Antigen Receptor T Cell-Associated Toxicities Using an Acute Lymphoblastic Leukemia Patient-Derived Xenograft Mouse Model at JoVE.com

This work was partly supported through the National Institutes of Health (R37CA266344, 1K99CA273304), Department of Defense (CA201127), Mayo Clinic K2R pipeline (S.S.K.), the Mayo Clinic Center for Individualized Medicine (S.S.K.), and the Predolin Foundation (R.L.S.). In addition, we would like to thank the Mayo Clinic NMR Core Facility staff. Figure 1 was created in BioRender.com

This protocol follows the guidelines of Mayo Clinic&#39;s Institutional Review Board (IRB), Institutional Animal Care and Use Committee (IACUC A00001767), and Institutional Biosafety Committee (IBC, Bios00000006.04).
NOTE: All the materials used to work with mice must be sterile.
1. Injection of busulfan to NSG mice
<ol>
	<li>Obtain male, 8-12 weeks old, immunocompromised, NOD-SCID IL2r&#947;null (NSG) mice, and weigh them prior to injection.<br /...

In this report, a methodology to assess CART cell-associated toxicities using an ALL PDX model has been described. More specifically, this model seeks to mimic two life-threatening toxicities, CRS and NI, that patients often experience after the infusion of CART cells. It recapitulates many hallmarks of CART toxicities observed in the clinic: weight loss, motor dysfunction, neuroinflammation, inflammatory cytokine and chemokine production, and the infiltration of different effector cells into the central nervous system<s...

An erratum was issued for:&#160;<a href="https://www.jove.com/t/64535">Assessment of Chimeric Antigen Receptor T Cell-Associated Toxicities Using an Acute Lymphoblastic Leukemia Patient-derived Xenograft Mouse Model</a>. The Authors section was updated from:
Claudia Manriquez Roman1,2,3,4,5 
R. Leo Sakemura1,2 
Fang Jin6 
Roman H. Khadka6 
Mohamad M. Adada1,2 
Elizabeth L. Siegler1,2 
Aaron J. Johnson6 
Saad S. Kenderian1,2,6 
1T Cell Engineering Laboratory, Mayo Clinic, Rochester, 
2Division of Hematology, Mayo Clinic, Rochester, 
3Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, 
4Department of Molecular Medicine, Mayo Clinic, Rochester, 
5Regenerative Sciences PhD Program, Mayo Clinic, Rochester, 
6Department of Immunology, Mayo Clinic, Rochester
to:
Claudia Manriquez Roman1,2,3,4,5 
R. Leo Sakemura1,2 
Brooke L. Kimball1,2 
Fang Jin6 
Roman H. Khadka6 
Mohamad M. Adada1,2 
Elizabeth L. Siegler1,2 
Aaron J. Johnson6 
Saad S. Kenderian1,2,6 
1T Cell Engineering Laboratory, Mayo Clinic, Rochester, 
2Division of Hematology, Mayo Clinic, Rochester, 
3Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, 
4Department of Molecular Medicine, Mayo Clinic, Rochester, 
5Regenerative Sciences PhD Program, Mayo Clinic, Rochester, 
6Department of Immunology, Mayo Clinic, Rochester

An erratum was issued for:&#160;<a href="https://www.jove.com/t/64535">Assessment of Chimeric Antigen Receptor T Cell-Associated Toxicities Using an Acute Lymphoblastic Leukemia Patient-derived Xenograft Mouse Model</a>. The Authors section was updated.

Erratum: Assessment of Chimeric Antigen Receptor T Cell-Associated Toxicities Using an Acute Lymphoblastic Leukemia Patient-derived Xenograft Mouse Model

Chimeric antigen receptor T (CART) cell therapy has revolutionized the field of cancer immunotherapy. It has proven to be successful in treating relapsed/refractory acute lymphoblastic leukemia (ALL), large B cell lymphoma, mantle cell lymphoma, follicular lymphoma, and multiple myeloma1,2,3,4,5,6,7, leading to recent FDA approvals. Despite the initial success in clinical trials, treatment with CART cell therapy results in toxicities that are often severe and occasionally lethal. The most common toxicities after CART cell therapy include the development of CRS and NI, also referred to as immune effector cell-associated neurotoxicity syndrome (ICANS)8,9. CRS is caused due to the overactivation and massive expansion of CART cells in vivo, leading to the subsequent secretion of multiple inflammatory cytokines, including interferon-&#947;, tumor necrosis factor-&#945;, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-6 (IL-6). This results in hypotension, high fevers, capillary leak syndrome, respiratory failure, multi-organ failure, and in some cases, death10,11. CRS develops in 50-100% of cases after CART19 cell therapy11,12,13. ICANS is another unique adverse event associated with CART cell therapy and is characterized by generalized cerebral edema, confusion, obtundation, aphasia, motor weakness, and occasionally, seizures9,14.&#160;Any grade of ICANS occurs in up to 70% of patients, and Grades 3-4 are reported in 20-30% of patients5,10,15,16. Overall, CRS and ICANS are common and can be fatal.
The management of ICANS after CART cell therapy is challenging. Most patients with ICANS also experience CRS17, which can often be treated with the IL-6 receptor antagonist tocilizumab or steroids18. A previous report revealed that early intervention with tocilizumab decreased the rate of severe CRS but did not affect the incidence or severity of ICANS19. Currently, there is no effective treatment or prophylactic agent for ICANS, and it is crucial to investigate preventive strategies20.
Myeloid cells and associated cytokines/chemokines are thought to be the main drivers of the development of CRS and ICANS21. While CRS is directly related to the extreme elevation of cytokines and T cell expansion, the pathophysiology of ICANS is largely unknown22,23. Therefore, it is imperative to establish a mouse model that recapitulates these toxicities after CART cell therapy to study the mechanisms and develop preventive strategies.
There are multiple preclinical animal models currently used to study, optimize, and validate the efficacy of CART cells, as well as to monitor their associated toxicities. These include syngeneic, xenograft, immunocompetent transgenic, humanized transgenic, and patient-derived xenograft mice, in addition to primate models. However, each of these models has drawbacks, and some do not reflect the true efficacy or safety concerns of CART cells24,25. Therefore, it is imperative to carefully choose the best model for the intended goals of the study.
This article seeks to describe the methodology that is used to assess CART cell-associated toxicities, CRS and NI, using an ALL patient-derived xenograft (PDX) in vivo model (Figure 1). Specifically, in the methods described here, CART19 cells generated in the authors&#39; laboratory are used following previously described protocols. Briefly, human T cells are isolated from healthy donor peripheral blood mononuclear cells (PBMCs) via a density gradient technique, stimulated with CD3/CD28 beads on day 0, and lentivirally transduced on day 1 with CARs composed of a CD19-targeted single chain variable fragment fused to 4-1BB and CD3&#950; signaling domains. These CART cells are then expanded, de-beaded on day 6, and cryopreserved on day 826,27,28,29,30. As outlined previously, mice are subjected to lymphodepleting treatment, followed by the administration of patient-derived leukemic blasts (ALL)28. First, tumor engraftment is verified via submandibular blood collection. Following the establishment of an appropriate tumor burden, CART19 cells are administered to the mice. Then, the mice are weighed daily to assess well-being. Small animal magnetic resonance imaging (MRI) is performed to assess NI, along with tail bleeding to assess T cell expansion and cytokine/chemokine production. The techniques described below are highly recommended to be used as a model to study CART cell-associated toxicities in a PDX model.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>&#160;APC Anti-Human CD19</td>
			<td>Biolegend</td>
			<td>302211</td>
			<td></td>
		</tr>
		<tr>
			<td>Alcohol Prep Pad</td>
			<td>Wecol</td>
			<td>6818</td>
			<td></td>
		</tr>
		<tr>
			<td>Analyze 14.0 software</td>
			<td>AnalyzeDirect Inc.</td>
			<td>N/A</td>
			<td>https://analyzedirect.com/analyze14/</td>
		</tr>
		<tr>
			<td>Artificial tears (Mineral oil and petrolatum)</td>
			<td>Akorn</td>
			<td>17478-062-35</td>
			<td>Topical ophtalmic gel to prevent eye dryness</td>
		</tr>
		<tr>
			<td>BD FACS Lysing Solution&#160;</td>
			<td>BD</td>
			<td>349202</td>
			<td>Red blood cells lysing buffer</td>
		</tr>
		<tr>
			<td>BD Micro-Fin IV insulin syringes</td>
			<td>BD</td>
			<td>329461</td>
			<td></td>
		</tr>
		<tr>
			<td>Brillian Violet 421 Anti-Human CD45</td>
			<td>Biolegend</td>
			<td>304032</td>
			<td></td>
		</tr>
		<tr>
			<td>Bruker Avance II 7 Tesla&#160;</td>
			<td>Bruker Biospin</td>
			<td>N/A</td>
			<td>MRI machine</td>
		</tr>
		<tr>
			<td>Busulfan (NSC-750)</td>
			<td>Selleckchem</td>
			<td>S1692</td>
			<td></td>
		</tr>
		<tr>
			<td>CountBright absolute counting beads</td>
			<td>Invitrogen</td>
			<td>C36950</td>
			<td></td>
		</tr>
		<tr>
			<td>CytoFLEX System B4-R2-V2</td>
			<td>Beckman Coulter</td>
			<td>C10343</td>
			<td>flow cytometer</td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Phosphate-Buffered Saline</td>
			<td>Gibco</td>
			<td>14190-144&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>ERT Control/Gating Module&#160;</td>
			<td>SA Instruments</td>
			<td>Model 1030</td>
			<td>Small Animal Monitoring Respiratory and Gating System</td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>Millipore Sigma</td>
			<td>F8067</td>
			<td></td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>Bright-Line</td>
			<td>Z359629-1EA</td>
			<td></td>
		</tr>
		<tr>
			<td>Human AB Serum; Male Donors; type AB; US</td>
			<td>Corning</td>
			<td>35-060-CI</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane (Liquid)</td>
			<td>Sigma-Aldrich</td>
			<td>792632</td>
			<td></td>
		</tr>
		<tr>
			<td>LIVE/DEAD Fixable Aqua Dead Cell Stain Kit, for 405 nm excitation</td>
			<td>Invitrogen</td>
			<td>L34966</td>
			<td></td>
		</tr>
		<tr>
			<td>Microvette 500 Lithium heparin</td>
			<td>Sarstedt</td>
			<td>20.1345.100</td>
			<td>Blood collection tube</td>
		</tr>
		<tr>
			<td>MILLIPLEX Huma/Cytokine/Chemokine Magnetic Beads Panel</td>
			<td>Millipore Sigma</td>
			<td>HCYTMAG-60K-PX38</td>
			<td>Immunology Multiplex Assay to identify cytokines and chemokines</td>
		</tr>
		<tr>
			<td>Omniscan</td>
			<td>Ge Healthcare Inc.</td>
			<td>0407-0690-10</td>
			<td>Gadolinium-based constrast agent</td>
		</tr>
		<tr>
			<td>Pd Anti-Mouse CD45</td>
			<td>Biolegend</td>
			<td>103106</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin-Glutamine (100x), Liquid</td>
			<td>Gibco</td>
			<td>10378-016</td>
			<td></td>
		</tr>
		<tr>
			<td>Round Bottom Polysterene Test tube</td>
			<td>Corning</td>
			<td>352008</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Azide, 5% (w/v)</td>
			<td>Ricca Chemical</td>
			<td>7144.8-16</td>
			<td></td>
		</tr>
		<tr>
			<td>Stainless Steel Surgical Blade</td>
			<td>Bard-Parker</td>
			<td>371215</td>
			<td></td>
		</tr>
		<tr>
			<td>X-VIVO 15 Serum-free Hematopoietic Cell Medium</td>
			<td>Lonza</td>
			<td>04-418Q</td>
			<td></td>
		</tr>
	</tbody>
</table>

assessment of chimeric antigen receptor t cell-associated toxicities using an acute lymphoblastic leukemia patient-derived xenograft mouse model

Chimeric antigen receptor T (CART) cell therapy has emerged as a powerful tool for the treatment of multiple types of CD19+ malignancies, which has led to the recent FDA approval of several CD19-targeted CART (CART19) cell therapies. However, CART cell therapy is associated with a unique set of toxicities that carry their own morbidity and mortality. This includes cytokine release syndrome (CRS) and neuroinflammation (NI). The use of preclinical mouse models has been crucial in the research and development of CART technology for assessing both CART efficacy and CART toxicity. The available preclinical models to test this adoptive cellular immunotherapy include syngeneic, xenograft, transgenic, and humanized mouse models. There is no single model that seamlessly mirrors the human immune system, and each model has strengths and weaknesses. This methods paper aims to describe a patient-derived xenograft model using leukemic blasts from patients with acute lymphoblastic leukemia as a strategy to assess CART19-associated toxicities, CRS, and NI. This model has been shown to recapitulate CART19-associated toxicities as well as therapeutic efficacy as seen in the clinic.

The aim of this protocol is to assess CART cell-associated toxicities using a PDX mice model from tumor cells of patients with ALL (Figure 1). First, NSG mice received i.p. injections of busulfan (30 mg/kg) with the goal of immunosuppressing them and facilitating CART cell engraftment28. The following day, they received ~5 &#215; 106 PBMCs (i.v.) derived from ALL patients. The mice were monitored for engraftment for ~13 weeks via the tail bleeding ...

Watch this Scientific Journal Video about Assessment of Chimeric Antigen Receptor T Cell-Associated Toxicities Using an Acute Lymphoblastic Leukemia Patient-Derived Xenograft Mouse Model at JoVE.com

Assessment of Chimeric Antigen Receptor T Cell-Associated Toxicities Using an Acute Lymphoblastic Leukemia Patient-Derived Xenograft Mouse Model

Here, we describe a protocol in which an acute lymphoblastic leukemia patient-derived xenograft model is used as a strategy to assess and monitor CD19-targeted chimeric antigen receptor T cell-associated toxicities.

Chimeric antigen receptor T (CART) cell therapy has emerged as a powerful tool for the treatment of multiple types of CD19+ malignancies, which has led to ...

This protocol utilizes human CAR-T and tumor cells and accurately demonstrates the toxicities associated with CART19 administration. Therefore, recapitulating what has been observed in the clinic. The main advantage of using this platform is that it provides a translatable and clinically relevant model where human T-cells and tumor cells are utilized.This model not only allows efficient assessment of CART19 associated toxicities, but also allows us to understand better how we can overcome these toxicities through improved treatment strategies. To begin, monitor the CART19 administered mice twice a day to assess any changes in their wellbeing, such as motor weakness, hunched body, and loss of body weight. Once the mice develop motor weakness and weight reduction, collect their peripheral blood to analyze the tumor burden.And conduct serum isolation for cytokines, as described in the manuscript. After isolation, store the serum micro-centrifuge tubes at 80 degrees Celsius, and use the cera to analyze the chemokines and cytokines using the multiplex assay. For MRI imaging, mix 120 microliters of gadolinium with 880 microliters of saline solution, and load into a one-milliliter insulin syringe.Inject 100 microliters of the prepared solution intraperitoneally into each mouse. Anesthetize the mouse and place it on the rodent-compatible cradle probe. Then hook its teeth on the bite bar.Pull the head of the mouse into the 25-millimeter volume coil, and adjust the nose cone tethered to the isoflurane anesthesia system. Tighten the knob of the bite bar to maintain the position for the duration of the scan. For breathing assessment, attach the probe of a breathing monitoring device close to the diaphragm, and secure it with surgical tape.Keep the respiration rate between 20 to 60 breaths-per-minute so that the mouses condition remains stable. Insert the animal probe into the small bore within the Vertical Bore Small Animal MRI system and adjust the animal's head at the center of the coil. Using the lock, secure the apparatus in the upright position and connect the instrument to the computer.Next, open the ParaVision software to set up the scan positions and types of scans. Determine the optimal sagittal and axial positions while keeping them consistent for all the experimental groups. To collect the T1-weighted MRI data, use T1-weighted multi-slice, multi-echo sequence with a repetition time of 300 milliseconds, an echo time of 9.5 milliseconds, a field of view of 4.00 X 2.00 X 2.00 centimeters, and a matrix of 192 X 96 X 96.For T2-weighted MRI images, use a multi-slice, multi-echo sequence with similar parameters. Once the scans are complete, remove the probe from the bore and gently extract the mouse by removing the teeth off the bite bar. After extracting data from the software, use analysis software for the quantification and 3D volume rendering of the hyperintensity regions CD19+tumor cell populations were compared between mice treated with CART19, and untreated mice using flow cytometry.Significant weight reduction was observed in mice treated with CART19 cells. Weight loss is considered as a symptom of CRS appearance, which is related to CART-cell associated toxicities. A multiplex assay revealed the expression of cytokines and chemokines in NSG mice serum before and after CART19 administration.T2-weighted images revealed evidence of edema and possible inflammatory infiltrate during neuroinflammation in CART19 treated mice. While the T1-weighted MRI showed contrast enhancement within the brain parenchyma, indicating increased vascular permeability. Three-dimensional reconstructions of the rodent brain were assembled based on T1 hyperintensity regions corresponding to vascular permeability, which renders the volume of gadolinium leakage in the brain.It's important to remember that the daily physical monitoring of the mice after CART19 administration, along with peripheral bleeding, will be the best indicator to proceed with MRI for fully assessing any changes in the brain indicative of CRS or neurotoxicity. This technology is widely applicable to additional CAR-T-cell therapies, and will allow scientists to efficiently test potential toxicities arising from novel CAR-T cells. This proposed model is a stepping stone in understanding how CAR-T-cell associated toxicities can be monitored, treated, and used to validate new CAR-T-cell models.

assessment-chimeric-antigen-receptor-t-cell-associated-toxicities

Research

JoVE Journal

Cancer Research

Development and Maintenance of a Preclinical Patient Derived Tumor Xenograft Model for the Investigation of Novel Anti-Cancer Therapies

Patient derived tumor xenograft (PDTX) models provide a necessary platform in facilitating anti-cancer drug development prior to human trials. Human tumor pieces are injected subcutaneously into athymic nude mice (immunocompromised, T cell deficient) to create a bank of tumors and subsequently are passaged into different generations of mice in order to maintain these tumors from patients. Importantly, cellular heterogeneity of the original tumor is closely emulated in this model, which provides a more clinically relevant model for evaluation of drug efficacy studies (single agent and combination), biomarker analysis, resistant pathways and cancer stem cell biology. Some limitations of the PDTX model include the replacement of the human stroma with mouse stroma after the first generation in mice, inability to investigate treatment effects on metastasis due to the subcutaneous injections of the tumors, and the lack of evaluation of immunotherapies due to the use of immunocompromised mice. However, even with these limitations, the PDTX model provides a powerful preclinical platform in the drug discovery process.

Utilizing patient-derived tumors in a subcutaneous preclinical model is an excellent way to study the efficacy of novel therapies, predictive biomarker discovery, and drug resistant pathways. This model, in the drug development process, is essential in determining the fate of many novel anti-cancer therapies prior to clinical investigation.

Patient derived tumor xenograft (PDTX) models provide a necessary platform in facilitating anti-cancer drug development prior to human trials. Human tumor ...

Preparation of Primary Acute Lymphoblastic Leukemia Cells in Different Cell Cycle Phases by Centrifugal Elutriation

The ability to synchronize cells has been central to advancing our understanding of cell cycle regulation. Common techniques employed include serum deprivation; chemicals which arrest cells at different cell cycle phases; or the use of mitotic shake-off which exploits their reduced adherence. However, all of these have disadvantages. For example, serum starvation works well for normal cells but less well for tumor cells with compromised cell cycle checkpoints due to oncogene activation or tumor suppressor loss. Similarly, chemically-treated cell populations can harbor drug-induced damage and show stress-related alterations. A technique which circumvents these problems is counterflow centrifugal elutriation (CCE), where cells are subjected to two opposing forces, centrifugal force and fluid velocity, which results in the separation of cells on the basis of size and density. Since cells advancing through the cycle typically enlarge, CCE can be used to separate cells into different cell cycle phases. Here we apply this technique to primary acute lymphoblastic leukemia cells. Under optimal conditions, an essentially pure population of cells in G1 phase and a highly enriched population of cells in G2/M phases can be obtained in excellent yield. These cell populations are ideally suited for studying cell cycle-dependent mechanisms of action of anticancer drugs and for other applications. We also show how modifications to the standard procedure can result in suboptimal performance and discuss the limitations of the technique. The detailed methodology presented should facilitate application and exploration of the technique to other types of cells.

This protocol describes the use of centrifugal elutriation to separate primary acute lymphoblastic leukemia cells into different cell cycle phases.

The ability to synchronize cells has been central to advancing our understanding of cell cycle regulation. Common techniques employed include serum ...

Flow Cytometry to Estimate Leukemia Stem Cells in Primary Acute Myeloid Leukemia and in Patient-derived-xenografts, at Diagnosis and Follow Up

Acute myeloid leukemia (AML) is a heterogeneous, and if not treated, fatal disease. It is the most common cause of leukemia-associated mortality in adults. Initially, AML is a disease of hematopoietic stem cells (HSC) characterized by arrest of differentiation, subsequent accumulation of leukemia blast cells, and reduced production of functional hematopoietic elements. Heterogeneity extends to the presence of leukemia stem cells (LSC), with this dynamic cell compartment evolving to overcome various selection pressures imposed upon during leukemia progression and treatment. To further define the LSC population, the addition of CD90 and CD45RA allows the discrimination of normal HSCs and multipotent progenitors within the CD34+CD38- cell compartment. Here, we outline a protocol to detect simultaneous expression of several putative LSC markers (CD34, CD38, CD45RA, CD90) on primary blast cells of human AML by multiparametric flow cytometry. Furthermore, we show how to quantify three progenitor populations and a putative LSC population with increasing degree of maturation. We confirmed the presence of these populations in corresponding patient-derived-xenografts. This method of detection and quantification of putative LSC may be used for clinical follow-up of chemotherapy response (i.e., minimal residual disease), as residual LSC may cause AML relapse.

We outline a protocol to detect simultaneous expression of leukemia stem cell markers on primary acute myeloid leukemia cells by flow cytometry. We show how to quantify three progenitor populations and a putative LSC population with increasing degree of maturation. We confirmed the presence of these populations in corresponding patient-derived-xenografts.

Acute myeloid leukemia (AML) is a heterogeneous, and if not treated, fatal disease. It is the most common cause of leukemia-associated mortality in ...

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 ...

Patient-derived Heterogeneous Xenograft Model of Pancreatic Cancer Using Zebrafish Larvae as Hosts for Comparative Drug Assessment

Patient-derived tumor xenograft (PDX) and cell-derived tumor xenograft (CDX) are important techniques for preclinical assessment, medication guidance and basic cancer researches. Generations of PDX models in traditional host mice are time-consuming and only working for a small proportion of samples. Recently, zebrafish PDX (zPDX) has emerged as a unique host system, with the characteristics of small-scale and high efficiency. Here, we describe an optimized methodology for generating a dual fluorescence-labeled tumor xenograft model for comparative chemotherapy assessment in zPDX models. Tumor cells and fibroblasts were enriched from freshly-harvested or frozen pancreatic cancer tissue at different culture conditions. Both cell groups were labeled by lentivirus expressing green or red fluorescent proteins, as well as an anti-apoptosis gene BCL2L1. The transfected cells were pre-mixed and co-injected into the 2 dpf larval zebrafish that were then bred in modified E3 medium at 32 &#176;C. The xenograft models were treated by chemotherapy drugs and/or BCL2L1 inhibitor, and the viabilities of both tumor cells and fibroblasts were investigated simultaneously. In summary, this protocol allows researchers to quickly generate a large amount of zPDX models with a heterogeneous tumor microenvironment and provides a longer observation window and a more precise quantitation in assessing the efficiency of drug candidates.

This protocol describes optimization procedures in a virus-based dual fluorescence-labeled tumor xenograft model using larval zebrafish as hosts. This heterogeneous xenograft model mimics the tissue composition of pancreatic cancer microenvironment in vivo and serves as a more precise tool for assessing drug responses in personalized zPDX (zebrafish patient-derived xenograft) models.

Patient-derived tumor xenograft (PDX) and cell-derived tumor xenograft (CDX) are important techniques for preclinical assessment, medication guidance and ...

A Melanoma Patient-Derived Xenograft Model

Accumulating evidence suggests that molecular and biological properties differ in melanoma cells grown in traditional two-dimensional tissue culture vessels versus in vivo in human patients. This is due to the bottleneck selection of clonal populations of melanoma cells that can robustly grow in vitro in the absence of physiological conditions. Further, responses to therapy in two-dimensional tissue cultures overall do not faithfully reflect responses to therapy in melanoma patients, with the majority of clinical trials failing to show the efficacy of therapeutic combinations shown to be effective in vitro. Although xenografting of melanoma cells into mice provides the physiological in vivo context absent from two-dimensional tissue culture assays, the melanoma cells used for engraftment have already undergone bottleneck selection for cells that could grow under two-dimensional conditions when the cell line was established. The irreversible alterations that occur as a consequence of the bottleneck include changes in growth and invasion properties, as well as the loss of specific subpopulations. Therefore, models that better recapitulate the human condition in vivo may better predict therapeutic strategies that effectively increase the overall survival of patients with metastatic melanoma. The patient-derived xenograft (PDX) technique involves the direct implantation of tumor cells from the human patient to a mouse recipient. In this manner, tumor cells are consistently grown under physiological stresses in vivo and never undergo the two-dimensional bottleneck, which preserves the molecular and biological properties present when the tumor was in the human patient. Notable, PDX models derived from organ sites of metastases (i.e., brain) display similar metastatic capacity, while PDX models derived from therapy naive patients and patients with acquired resistance to therapy (i.e., BRAF/MEK inhibitor therapy) display similar sensitivity to therapy.

Patient-derived xenograft (PDX) models more robustly recapitulate melanoma molecular and biological features and are more predictive of therapy response compared to traditional plastic tissue culture-based assays. Here we describe our standard operating protocol for the establishment of new PDX models and the characterization/experimentation of existing PDX models.

Accumulating evidence suggests that molecular and biological properties differ in melanoma cells grown in traditional two-dimensional tissue culture ...

Establishment of Gastric Cancer Patient-derived Xenograft Models and Primary Cell Lines

The use of preclinical models to advance our understanding of tumor biology and investigate the efficacy of therapeutic agents is key to cancer research. Although there are many established gastric cancer cell lines and many conventional transgenic mouse models for preclinical research, the disadvantages of these in vitro and in vivo models limit their applications. Because the characteristics of these models have changed in culture, they no longer model tumor heterogeneity, and their responses have not been able to predict responses in humans. Thus, alternative models that better represent tumor heterogeneity are being developed. Patient-derived xenograft (PDX) models preserve the histologic appearance of cancer cells, retain intratumoral heterogeneity, and better reflect the relevant human components of the tumor microenvironment. However, it usually takes 4-8 months to develop a PDX model, which is longer than the expected survival of many gastric patients. For this reason, establishing primary cancer cell lines may be an effective complementary method for drug response studies. The current protocol describes methods to establish PDX models and primary cancer cell lines from surgical gastric cancer samples. These methods provide a useful tool for drug development and cancer biology research.

The current protocol describes methods to establish patient-derived xenograft (PDX) models and primary cancer cell lines from surgical gastric cancer samples. The methods provide a useful tool for drug development and cancer biology research.

The use of preclinical models to advance our understanding of tumor biology and investigate the efficacy of therapeutic agents is key to cancer research. ...

Manufacturing Chimeric Antigen Receptor (CAR) T Cells for Adoptive Immunotherapy

Adoptive immunotherapy holds promise for the treatment of cancer and infectious disease. We describe a simple approach to transduce primary human T cells with chimeric antigen receptor (CAR) and expand their progeny ex vivo. We include assays to measure CAR expression as well as differentiation, proliferative capacity and cytolytic activity. We describe assays to measure effector cytokine production and inflammatory cytokine secretion in CAR T cells. Our approach provides a reliable and comprehensive method to culture CAR T cells for preclinical models of adoptive immunotherapy.

Manufacturing Chimeric Antigen Receptor CAR T Cells for Adoptive Immunotherapy

We describe an approach to reliably generate chimeric antigen receptor (CAR) T cells and test their differentiation and function in vitro and in vivo.

Adoptive immunotherapy holds promise for the treatment of cancer and infectious disease. We describe a simple approach to transduce primary human T cells ...

The Establishment and Utilization of Patient Derived Xenograft Models of Central Nervous System Metastasis

The development of novel therapies for central nervous system (CNS) metastasis has been hindered by the lack of preclinical models that accurately represent the disease. Patient derived xenograft (PDX) models of CNS metastasis have been shown to better represent the phenotypic and molecular characteristics of the human disease, as well as better reflect the heterogeneity and clonal dynamics of human patient tumors compared to historic cell line models. There are multiple sites that can be used to implant patient-derived tissue when setting up preclinical trials, each with their own advantages and disadvantages, and each suited for studying different aspects of the metastatic cascade. Here, the protocol describes how to establish PDX models and present three different approaches for utilizing CNS metastasis PDX models in pre-clinical studies, discussing each of their applications and limitations. These include flank implantation, orthotopic injection in the brain, and intracardiac injection. Subcutaneous flank implantation is the easiest to monitor and, therefore, most convenient for pre-clinical studies. In addition, metastases to brain and other tissues from flank implantation were observed, indicating that the tumor has undergone multiple steps of metastasis, including intravasation, extravasation, and colonization. Orthotopic injection in the brain is the best option for recapitulating the brain tumor microenvironment and is useful for determining the efficacy of biologics to cross the blood-brain barrier (BBB) but bypasses most steps of the metastatic cascade. Intracardiac injection facilitates metastasis to the brain and is also useful for studying organ tropism. While this method forgoes earlier steps of the metastatic cascade, these cells will still have to survive circulation, extravasate, and colonize. The utility of a PDX model, is therefore, impacted by the route of tumor inoculation and the choice of which one to utilize should be dictated by the scientific question and overall goals of the experiment.

Central nervous system metastasis PDX models represent the phenotypic and molecular characteristics of human metastasis, making them excellent models for preclinical studies. Described here is how to establish PDX models and the inoculation routes that are best used for preclinical studies.

The development of novel therapies for central nervous system (CNS) metastasis has been hindered by the lack of preclinical models that accurately ...

Dynamic Imaging of Chimeric Antigen Receptor T Cells with [18F]Tetrafluoroborate Positron Emission Tomography/Computed Tomography

T cells genetically engineered to express chimeric antigen receptors (CAR) have shown unprecedented results in pivotal clinical trials for patients with B cell malignancies or multiple myeloma (MM). However, numerous obstacles limit the efficacy and prohibit the widespread use of CAR T cell therapies due to poor trafficking and infiltration into tumor sites as well as lack of persistence in vivo. Moreover, life-threatening toxicities, such as cytokine release syndrome or neurotoxicity, are major concerns. Efficient and sensitive imaging and tracking of CAR T cells enables the evaluation of T cell trafficking, expansion, and in vivo characterization and allows the development of strategies to overcome the current limitations of CAR T cell therapy. This paper describes the methodology for incorporating the sodium iodide symporter (NIS) in CAR T cells and for CAR T cell imaging using [18F]tetrafluoroborate-positron emission tomography ([18F]TFB-PET) in preclinical models. The methods described in this protocol can be applied to other CAR constructs and target genes in addition to the ones used for this study.

Dynamic Imaging of Chimeric Antigen Receptor T Cells with [18F]Tetrafluoroborate Positron Emission Tomography/Computed Tomography

This protocol describes the methodology for non-invasively tracking T cells genetically engineered to express chimeric antigen receptors in vivo with a clinically available platform.

T cells genetically engineered to express chimeric antigen receptors (CAR) have shown unprecedented results in pivotal clinical trials for patients with B ...