Name: expression of exogenous cytokine in patient-derived xenografts via injection with a cytokine-transduced stromal cell line
Uploaded: 2017-05-10T12:30:00
Description: Watch this Scientific Journal Video about Expression of Exogenous Cytokine in Patient-derived Xenografts via Injection with a Cytokine-transduced Stromal Cell Line at JoVE.com

This work was supported by NIH R21CA162259, NIH R01CA209829, NIH P20 MD006988, NIH 2R25 GM060507, a Hyundai Hope on Wheels Scholar Hope Grant, the Department of Pathology and Human Anatomy, the Department of Basic Sciences, and the Center for Health Disparities and Molecular Medicine at Loma Linda University School of Medicine and by a Grant to Promote Collaborative and Translational Research from Loma Linda University (KJP). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

Studies were conducted in accordance with Loma Linda University&#39;s Institutional Animal Care and Use Committee (IACUC) and Institutional Review Board (IRB) approved protocols and according to all federal guidelines.
CAUTION: PDX and human tissues should be handled in accordance with safety procedures to prevent the transmission of blood borne pathogens.
1. Culture and Expansion of Cytokine-Transduced Stromal Cells
NOTE: Each time stroma ...

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W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+and+human+IL-7+activate+STAT5+and+induce+proliferation+of+normal+human+pro-B+cells.">Murine and human IL-7 activate STAT5 and induce proliferation of normal human pro-B cells.</a> J Immunol. 175 (11), 7325-7331 (2005).</li><li>Milford, T. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TSLP+or+IL-7+provide+an+IL-7Ralpha+signal+that+is+critical+for+human+B+lymphopoiesis.">TSLP or IL-7 provide an IL-7Ralpha signal that is critical for human B lymphopoiesis.</a> Eur J Immunol. 46 (9), 2155-2161 (2016).</li><li>Reche, P. 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K., 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=Aberrant+STAT5+and+PI3K/mTOR+pathway+signaling+occurs+in+human+CRLF2-rearranged+B-precursor+acute+lymphoblastic+leukemia.">Aberrant STAT5 and PI3K/mTOR pathway signaling occurs in human CRLF2-rearranged B-precursor acute lymphoblastic leukemia.</a> Blood. 120 (4), 833-842 (2012).</li><li>Kalaitzidis, D., Neel, B. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow-cytometric+phosphoprotein+analysis+reveals+agonist+and+temporal+differences+in+responses+of+murine+hematopoietic+stem/progenitor+cells.">Flow-cytometric phosphoprotein analysis reveals agonist and temporal differences in responses of murine hematopoietic stem/progenitor cells.</a> PLoS One. 3 (11), (2008).</li><li>Machholz, E., Mulder, G., Ruiz, C., Corning, B. 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This manuscript describes a simple, quick, and relatively cost effective method for engineering PDX to express exogenous human cytokine. The strategy described here is based on weekly intraperitoneal injections of a stromal cell line transduced to express the human cytokine, TSLP. Prior to performing the methods described here, stroma engineered to express high levels of the cytokine of interest (TSLP) and similarly engineered control stroma were generated. In the protocols presented here, stroma are expanded in culture ...

Patient-derived xenografts (PDX) are a powerful in vivo model for studying the production of normal and malignant hematopoietic cells in a &#39;native&#39; mammalian environment. Most often, PDX are produced by injecting or transplanting human cells into immune deficient mice. The production of PDX using normal human hematopoietic stem cells allows in vivo studies of normal human blood and immune cell development. PDX produced from leukemia or other cancer cells make it possible to study oncogenic mechanisms and to identify effective therapies in context of the range of genetic landscapes and mutations present in the human population.1 Consequently, PDX are the current gold standard for translational biomedical research to identify effective therapies and an important tool for understanding mechanisms of cancer progression. PDX models are an essential tool to aid research into health disparities diseases due to specific genetic lesions, or any disease in which the variations of a patient&#39;s genetic landscape can substantially contribute to oncogenesis and treatment outcome.
Mouse-human PDX models are possible because many mouse cytokines adequately mimic their human analogs in activating the cytokine receptors of human cells while they are inside the mouse. For example, interleukin-7 (IL-7) provides a critical signal for human B cell development.2 In this case, mouse IL-7 has sufficient homology with human IL-7 that the mouse cytokine stimulates signaling pathways in human B cell precursors.2,3,4 However, this is not the case for thymic stromal lymphopoietin (TSLP),5,6 which among other cytokines (IL-3, granulocyte-macrophage colony stimulating factor (GM-CSF), stem cell factor (SCF),7 is important for the production of normal and malignant human hematopoietic cells. When mouse and human cytokines show low homology the mouse cytokines do not activate their respective receptors on human cells. To overcome this obstacle, a number of strategies have been used to engineer expression of human cytokines in PDX mice. These include injection of recombinant human cytokines, hydrodynamic injection of DNA, lentiviral expression, transgenic expression and knockin gene replacement.7 This report describes a method for engineering PDX to produce human cytokine via stromal-mediated cytokine delivery (Figure 1).
In the method demonstrated here, PDX mice are engineered to express the human cytokine, TSLP, or to serve as cytokine-negative controls. TSLP-expressing PDX are achieved by weekly intraperitoneal injections of stromal cells that have been transduced to express high levels of human TSLP. Cytokine-negative PDX &#34;control&#34; mice are similarly engineered; though control stroma are transduced with a control vector. This method achieves normal physiological levels of human TSLP in PDX mice injected with the TSLP+ stroma. No detectable TSLP is observed in PDX mice receiving the cytokine-negative stroma. We selected the human stromal cell line HS-27A for our studies because it grows robustly in culture and shows very low level of cytokine production that does not support proliferation of isolated progenitor cells in cocultures.8 For human TSLP expression, stroma were transduced with an advanced generation self-inactivating lentiviral vector derived from a previously described backbone,9 and includes the cPPT/cts element and the woodchuck hepatitis post-transcriptional regulatory element (WPRE) to increase transgene expression. The human TSLP gene was constructed into this vector under the control of the elongation factor-1 (EF-1) alpha promoter to achieve robust, constitutive, and long-term expression.
The engineering of this human-cytokine enhanced PDX model consists of 4 major steps. First, transduced stroma are expanded in vitro and assessed by enzyme-linked immunosorbent assay (ELISA) for stable, high level cytokine production. Second, the activity of human cytokine produced by the transduced stromal cells (and lack of cytokine activity from control stroma) is verified using phospho-flow cytometry. Cell lines known to be responsive to cytokine of interest (in this instance,TSLP) are incubated with stromal cell supernatant and assayed for cytokine-induced phosphorylation. Third, mice are injected with transduced human stroma and then mouse plasma is assessed by ELISA for levels of human cytokine on a weekly basis. Fourth, human hematopoietic cells are transplanted and the in vivo functional effects of the human cytokine is evaluated on a known target (e.g. cell population).
<img alt="Figure 1" src="/files/ftp_upload/55384/55384fig1.jpg" /> 
Figure 1: PDX Model Engineered to Produce Exogenous Human Cytokine in Mice. (1A) Design experiment and obtain transduced human stromal cells (1B) Obtain human cells (hematopoietic stem cells, leukemia cells, etc.) to generate PDX (patient-derived xenograft) mice. (2A) Inject engineered stroma and (2B) transplant human cells into immune deficient mice according experimental schedule. (3A-B) Monitor cytokine concentrations in the stroma supernatant and the mouse plasma by ELISA. (4) Harvest human cells and assess the in vivo functional effects of the human cytokine present in the PDX. <a href="http://cloudflare.jove.com/files/ftp_upload/55384/55384fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Delivery of human cytokine via stromal cells offers both advantages and disadvantages when compared to other methods of delivering/producing human cytokines in PDX mice.7 Compared to injection of recombinant human cytokine, stroma-mediated delivery is generally less expensive (cost of stromal cell culture is less than cost of recombinant cytokine) and less labor intensive (one injection per week versus multiple injections per week). The issue of short cytokine half-life is also mitigated since stroma continually produce the exogenous cytokine. Delivery of cytokine via hydrodynamic injection of DNA may be less expensive than delivery via stroma. However, it is similarly transient and may require more technical skill than the simple weekly intraperitoneal injection required for stroma-mediated delivery. Lentiviral gene expression in the mouse may provide a less transient method of cytokine delivery; however, in our hands physiological TSLP levels were not achieved. Additionally, this method is labor intensive, requiring continuous production of lentiviral vector. Transgenic or knock-in mice offer stable long-term expression of cytokine and can be engineered for tissue specific expression, which can be an advantage. On the other hand, the transgenic expression of the human cytokine gene on the immune deficient mouse background required for PDX mice, necessitates an immense investment of resources before the value of the model has been established. Furthermore, transgenic models do not generally allow for the option of varying the timing of cytokine initiation or level of in vivo cytokine production. These can be achieved with stroma-mediated delivery by simply changing the time point for initiation of stromal cell injection or the dose of stromal cells injected.
The stromal-cell mediated cytokine delivery method detailed here was used to develop PDX for evaluating the role of TSLP in normal human B cell development4,6 and high risk B-cell acute lymphoblastic leukemia.6 This method provides an alternative cytokine delivery method for use in generating similar models with human cytokines other than TSLP. This model can also be useful for generating preliminary data that can help determine whether the value of a cytokine transgenic or cytokine knock-in PDX model would be worthy of the substantial time and money investment.

<table border="0" cellpadding="0" cellspacing="0" width="1101">
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			<td height="21" style="height:21px;width:665px;">Wet lab reagents&#160;</td>
			<td style="width:212px;"></td>
			<td style="width:136px;"></td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">T-25 Nunc Cell Culture Treated EasYFlasks, 7 mL capacity,&#160; 25cm&#178; culture area</td>
			<td style="width:212px;">Thermo Scientific / Fisher</td>
			<td style="width:136px;">156367</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">T-75 Falcon Tissue Culture Treated Flask, 250 mL capacity, 75 cm&#178; culture area &#38; vented cap</td>
			<td style="width:212px;">Corning Inc. / Fisher</td>
			<td style="width:136px;">353136</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">T-150 Falcon Tissue Culture Treated Flask, 600 mL capacity, 150 cm&#178; culture area &#38; vented cap</td>
			<td style="width:212px;">Corning Inc. / Fisher</td>
			<td style="width:136px;">355001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">10 mL serological pipettes</td>
			<td style="width:212px;">Falcon</td>
			<td style="width:136px;">357551</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">15 mL&#160; polypropylene conical tubes</td>
			<td style="width:212px;">Fisher</td>
			<td style="width:136px;">05-539-12</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">5 mL round-bottom polystyrene tubes</td>
			<td style="width:212px;">Falcon</td>
			<td style="width:136px;">352054</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">50 mL polypropylene conical tubes</td>
			<td style="width:212px;">Falcon</td>
			<td style="width:136px;">352098</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">2.0 mL cryogenic vials, externally threaded</td>
			<td style="width:212px;">Corning Inc. / Fisher</td>
			<td style="width:136px;">4230659</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">1 mL pipette tips</td>
			<td style="width:212px;">Fisher</td>
			<td style="width:136px;">2707509</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">200 &#956;L pipette tips&#160;</td>
			<td style="width:212px;">Denville Scientific</td>
			<td style="width:136px;">P3020-CPS</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">10 &#956;L pipette tips</td>
			<td style="width:212px;">Denville Scientific</td>
			<td style="width:136px;">P-1096-CP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Sterile Disposable Filter Units with SFCA Membrane, Nalgene Rapid-Flow</td>
			<td style="width:212px;">Fisher</td>
			<td style="width:136px;">09-740-28D</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:665px;">2N H2SO4&#160;</td>
			<td style="width:212px;">BioLegend</td>
			<td style="width:136px;">423001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Dulbecco&#8217;s phosphate-buffered saline (PBS) without calicium and magnesium, 1&#215;</td>
			<td style="width:212px;">Corning cellgro/ Mediatech</td>
			<td style="width:136px;">21-031-CV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Human TSLP ELISA Max Deluxe Set</td>
			<td style="width:212px;">BioLegend</td>
			<td style="width:136px;">434204</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">3% Acetic Acid with Methylene Blue</td>
			<td style="width:212px;">Stemcell Technologies</td>
			<td style="width:136px;">7060</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Trypan Blue&#160;</td>
			<td style="width:212px;">Corning</td>
			<td style="width:136px;">25-900-Cl</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#34;Trypsin&#34; 1x 0.25% Trypsin 2.21 mM EDTA in HBSS</td>
			<td style="width:212px;">ThermoFisher</td>
			<td style="width:136px;">25-053</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">TWEEN 20 BioXtra</td>
			<td style="width:212px;">Sigma-Aldrich</td>
			<td style="width:136px;">P-7949</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#8220;R10&#8221; cell culture medium, % of total volume (makes 565 mL)</td>
			<td style="width:212px;">-</td>
			<td style="width:136px;">-</td>
			<td style="width:88px;">Lab Recipe</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">RPMI, 88.5% (500 mL)&#160;</td>
			<td style="width:212px;">Mediatech</td>
			<td style="width:136px;">10-040-CV&#160;&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">FBS, 9.9% (56 mL)&#160;</td>
			<td style="width:212px;">Mediatech</td>
			<td style="width:136px;">35-011-CV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">L-Glutamine, 0.99% (5.6 mL)&#160;</td>
			<td style="width:212px;">Mediatech</td>
			<td style="width:136px;">25-005-Cl</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Penicillin-Streptomycin, 0.50% (2.8 mL)&#160;</td>
			<td style="width:212px;">Mediatech</td>
			<td style="width:136px;">30-002-Cl</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">2-Mercaptoethanol, 0.10% (560 &#181;L)&#160;</td>
			<td style="width:212px;">MP</td>
			<td style="width:136px;">190242</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#8220;R20&#8221; cell culture medium, % of total volume (makes 195 mL)</td>
			<td style="width:212px;">-</td>
			<td style="width:136px;">-</td>
			<td style="width:88px;">Lab Recipe</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#160;&#160;&#160;&#160; RPMI, 76.84% (150&#160; mL)</td>
			<td style="width:212px;">see above</td>
			<td style="width:136px;">see above</td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#160;&#160;&#160;&#160; FBS, 20.49% (40 mL)</td>
			<td style="width:212px;">see above</td>
			<td style="width:136px;">see above</td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#160;&#160;&#160;&#160; 2mM L-glutamine, 1.02% (2 mL)</td>
			<td style="width:212px;">see above</td>
			<td style="width:136px;">see above</td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#160;&#160;&#160;&#160; 1mM Na pyruvate, 1.02% (2 mL )</td>
			<td style="width:212px;">see above</td>
			<td style="width:136px;">see above</td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#160;&#160;&#160;&#160; Penicillin-Streptomycin,&#160; 0.51% (1 mL)</td>
			<td style="width:212px;">see above</td>
			<td style="width:136px;">see above</td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#160;&#160;&#160;&#160; 2-Mercaptoethanol, 0.10% (0.1 M),&#160; 0.10% (200 &#181;L)</td>
			<td style="width:212px;">see above</td>
			<td style="width:136px;">see above</td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#8220;Freezing medium&#8221;, % of total volume</td>
			<td style="width:212px;">-</td>
			<td style="width:136px;">-</td>
			<td style="width:88px;">Lab Recipe</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#8220;R10&#8221; medium, 45%</td>
			<td style="width:212px;">see &#34;R10&#34; recipe</td>
			<td style="width:136px;">-</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">FBS, 20%</td>
			<td style="width:212px;">see above</td>
			<td style="width:136px;">35-011-CV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">DMSO, 10%</td>
			<td style="width:212px;">Corning</td>
			<td style="width:136px;">25-950-CQC</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:665px;">D(-)(+)-Trehalose dihydrate, 5%</td>
			<td style="width:212px;">Fisher Scientific</td>
			<td style="width:136px;">BP2687-100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Name</td>
			<td style="width:212px;">Company</td>
			<td style="width:136px;">Catolog Number</td>
			<td style="width:88px;">Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Biologics&#160;</td>
			<td style="width:212px;"></td>
			<td style="width:136px;"></td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#34;HS-27&#34; HS-27A human stroma line</td>
			<td style="width:212px;">ATCC</td>
			<td>CRL-2496</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#34;CALL-4&#34; MHH-CALL-4 cell line, human B cell precursor leukemia</td>
			<td style="width:212px;">DSMZ</td>
			<td style="width:136px;">ACC 337</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:665px;">&#8220;NSG mice&#8221; NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ, male or female, age 6 &#8211; 8 weeks</td>
			<td style="width:212px;">JAX Mice&#160;</td>
			<td style="width:136px;"># 005557</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">MUTZ-5 cell line, human B cell precursor leukemia</td>
			<td style="width:212px;">DSMZ</td>
			<td style="width:136px;">ACC 490</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:665px;">Recombinant Human TSLP protein</td>
			<td style="width:212px;">R&#38;D Systems</td>
			<td style="width:136px;">1398-TS-010</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Name</td>
			<td style="width:212px;">Company</td>
			<td style="width:136px;">Catolog Number</td>
			<td style="width:88px;">Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Flow cytomery antibodies (clone)*</td>
			<td style="width:212px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Anti-mouse CD45 FITC (30F11)</td>
			<td>Miltenyi Biotec</td>
			<td>130-102-778</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">CD127 PE (MB15-18C9) (alternate name is IL-7R&#945;)</td>
			<td>Miltenyi Biotec</td>
			<td>130-098-094</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">CD34 APC (8G12)</td>
			<td>BD Biosciences</td>
			<td>340667</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">CD45 PE-Cy7&#160; (HI30)</td>
			<td>eBioscience</td>
			<td>25-0459</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">&#34;FVD&#34; Fixable viability dye&#160; eFluor 780&#160;</td>
			<td>eBioscience</td>
			<td>65-0865</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Ig &#954; light chain FITC&#160; (G20-193)</td>
			<td style="width:212px;">BD Pharmingen</td>
			<td>555791</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Ig &#955; light chain FITC (JDC-12)</td>
			<td style="width:212px;">BD Pharmingen</td>
			<td>561379</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">IgD PE (IA6-2)</td>
			<td style="width:212px;">BioLegend</td>
			<td>348203</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">IgM PE-Cy5 (G20-127)</td>
			<td>BD Biosciences</td>
			<td>551079</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:665px;">pSTAT5 PE,&#160; mouse anti-STAT5 (pY694)</td>
			<td style="width:212px;">BD PhosphoFlow</td>
			<td>612567</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Name</td>
			<td style="width:212px;">Company</td>
			<td style="width:136px;">Catolog Number</td>
			<td style="width:88px;">Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Other materials &#38; equipment&#160;</td>
			<td style="width:212px;"></td>
			<td style="width:136px;"></td>
			<td style="width:88px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Animal Implantable Nano Transponder with Canula</td>
			<td style="width:212px;">Trovan&#160;</td>
			<td style="width:136px;">ID-100B(1.25)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">EMLA lidocaine anesthetic cream (obtain by presciption through animal care facility)</td>
			<td style="width:212px;">perscription</td>
			<td style="width:136px;">perscription</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BD &#189; cc LO-DOSE U-100 Insulin Syringe 28G&#189;&#160;</td>
			<td style="width:212px;">BD</td>
			<td style="width:136px;">#329461</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:665px;">BD Microtainer Tubes with K2EDTA</td>
			<td style="width:212px;">BD&#160;</td>
			<td style="width:136px;">#365974</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Centrifuge</td>
			<td>Beckman Coulter</td>
			<td style="width:136px;">Alegra X-15R&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FisherBrand Capillary Tubes (Heparinized)</td>
			<td style="width:212px;">Fisher Scientific</td>
			<td style="width:136px;">22-260-950</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Hemocytometer</td>
			<td style="width:212px;">Fisher</td>
			<td style="width:136px;">02-671-6</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">MACSQuant Analyzer 10</td>
			<td style="width:212px;">Miltenyi Biotec</td>
			<td style="width:136px;">130-096-343</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Mouse Pie Cage</td>
			<td style="width:212px;">Braintree Scientific, Inc.</td>
			<td style="width:136px;">MPC-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Mouse Tail Illuminator Restrainer</td>
			<td style="width:212px;">Braintree Scientific, Inc.</td>
			<td style="width:136px;">MTI STD</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">Pistol Grip Implanter</td>
			<td style="width:212px;">Trovan&#160;</td>
			<td style="width:136px;">IM-300(1.25)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">&#181;Quant&#160;</td>
			<td style="width:212px;">Bio-Tek Instruments Inc.</td>
			<td style="width:136px;">MQX200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:665px;">FlowJo flow cytometry analysis software</td>
			<td>FlowJo, LLC</td>
			<td style="width:136px;">Version 10</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">*All antibodies are anti-human unless otherwise stated.</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

expression of exogenous cytokine in patient-derived xenografts via injection with a cytokine-transduced stromal cell line

Patient-derived xenograft (PDX) mice are produced by transplanting human cells into immune deficient mice. These models are an important tool for studying the mechanisms of normal and malignant hematopoiesis and are the gold standard for identifying effective chemotherapies for many malignancies. PDX models are possible because many of the mouse cytokines also act on human cells. However, this is not the case for all cytokines, including many that are critical for studying normal and malignant hematopoiesis in human cells. Techniques that engineer mice to produce human cytokines (transgenic and knock-in models) require significant expense before the usefulness of the model has been demonstrated. Other techniques are labor intensive (injection of recombinant cytokine or lentivirus) and in some cases require high levels of technical expertise (hydrodynamic injection of DNA). This report describes a simple method for generating PDX mice that have exogenous human cytokine (TSLP, thymic stromal lymphopoietin) via weekly intraperitoneal injection of stroma that have been transduced to overexpress this cytokine. Use of this method provides an in vivo source of continuous cytokine production that achieves physiological levels of circulating human cytokine in the mouse. Plasma levels of human cytokine can be varied based on the number of stromal cells injected, and cytokine production can be initiated at any point in the experiment. This method also includes cytokine-negative control mice that are similarly produced, but through intraperitoneal injection of stroma transduced with a control vector. We have previously demonstrated that leukemia cells harvested from TSLP-expressing PDX, as compared to control PDX, exhibit a gene expression pattern more like the original patient sample. Together the cytokine-producing and cytokine-negative PDX mice produced by this method provide a model system that we have used successfully to study the role of TSLP in normal and malignant hematopoiesis.

An overview of the model is shown in Figure 1. Once cytokine-producing (TSLP+ stroma) and control stroma have been obtained they are expanded in culture. Prior to stroma injection into mice, stromal cell supernatant is assessed by ELISA to verify cytokine production (Figure 2) and phospho-flow cytometry (Protocol #3) is used to verify the activity of the cytokine produced by the stroma. Supernatant is collected from confluent stromal cell cultures (contro...

Watch this Scientific Journal Video about Expression of Exogenous Cytokine in Patient-derived Xenografts via Injection with a Cytokine-transduced Stromal Cell Line at JoVE.com

Expression of Exogenous Cytokine in Patient-derived Xenografts via Injection with a Cytokine-transduced Stromal Cell Line

Described here is a method for producing exogenous cytokine in patient-derived xenograft (PDX) mice via weekly intraperitoneal injection of a cytokine-transduced stromal cell line. This method broadens the utility of PDX and provides the option for transient or sustained exogenous cytokine delivery in a multitude of PDX models.

Patient-derived xenograft (PDX) mice are produced by transplanting human cells into immune deficient mice. These models are an important tool for studying ...

The overall goal of this procedure is to produce xenograft mice with circulating human cytokines. This method can help answer key questions in the cancer and hematopoiesis fields such as, What is the role of a specific cytokine in normal and malignant lymphocyte development? The main advantage of this technique is that investigators can ingest the circulating concentrations of exogenous cytokine in their xenograft animals according to the needs of their experiment.This eliminates the need to produce new and expensive transgenic mouse lines. This technique will be useful for researching new cancer therapies, because this preclinical model can be used to test anticancer drugs, similar to what is used in the clinic. Though this method can provide insight into normal hematopoiesis, it can also be used to study specific diseases such as leukemia.I first developed this idea when we needed an in vivo model to evaluate the role of the TSLP cytokine in normal and malignant human B-cell production. Begin by plating freshly thawed control empty vector-transduced stroma in cytokine-producing cells in five milliliters of R-10 medium in individual T25 flasks. For their culture, at 37 degrees Celsius in five percent CO2 for 24 to 48 hours.When the stroma are confluent, detach the cells with Trypsan in EDTA for replating in T150 culture flasks for three to four days. When the stroma achieve confluence in the T150 flasks, collect the supernatants and freeze them at 80 degrees Celsius for later evaluation of their cytokine production by ELISA. Then, passage each T150 flask culture into three new T150 flasks for their culture until confluency.To store the cells after the appropriate number of passages, transfer the harvested cell suspensions to a conical tube for centrifugation and resuspend the pellets in a freezing medium. Then transfer 1.5E6 cell aliquots into long-term storage tubes for their storage in liquid nitrogen. To validate the supernatant produced from engineered stroma, thaw the supernatant samples harvested from the control in cytokine-expressing stroma, and plate three wells of leukemia cell lines per condition in Au-20 medium at a 2E5 cells per well concentration in a 96-well tissue culture plate.Incubate the cells for two hours at 37 degrees Celsius to allow for the phosphorylation from their prior culture to be lost. Then transfer the cells from each well into individual four milliliter tubes and collect the cells by centrifugation. Resuspend the pellets in 600 microliters per experimental condition.Plate 200 microliters of cells per well for each condition in triplicate. Incubate the cells for the appropriate period according to the specific commercial phosphoassay. At the end of the incubation, pellet the cells by centrifugation.Label the cells via phospho-flow cytometry staining according to the manufacturer's protocol. Then analyze the cells by flow cytometry using standard flow cytometric analysis protocols to verify that cytokine in the stroma supernatant phosphorylates the leukemia cells. After a minimum of three post-thaw passages, transfer the harvested stromal cell suspensions into individual conical tubes for counting.Pellet the cells by centrifugation and gently resuspend them in the appropriate volumes of sterile PBS for injection. Hold the cells at four degrees Celsius until immediately before the injection at which point the suspension should be warmed to at least room temperature. When the cells are ready, gently mix the first sample by inversion and draw 200 microliters of the cells into a tuberculin syringe.Then restrain the first animal and inject the cells into the peritoneal cavity using standard intraperitoneal injection techniques. To collect a peripheral blood sample, first gently position the mouse in a disinfected small animal restrainer and secure the tube to minimize the animal's movements. Next, scrub the tail with fresh isopropyl alcohol followed by the application of topical anesthetic cream.Using very sharp surgical scissors, snip about 5 to one millimeter from the tip of the tail and collect approximately 80 microliters of peripheral blood into heparinized capillary tubes. Use a bulb syringe to transfer the blood samples into labeled potassium EDTA microtainer tubes and invert the tube 20 times to prevent coagulation. After centrifuging blood collection tubes per manufacturer's instructions, carefully collect the plasma layer and store the aliquots at 20 degrees Celsius and aliquot the plasma for 20 degree Celsius storage.On the day of the ELISA, thaw the frozen mouse plasma samples and serially dilute the ELISA standard into 120-microliter volumes. Now plate 40 microliters of each standard in triplicate into the appropriate wells of the ELISA plate followed by the addition of 40 microliters of each mouse plasma sample to the appropriate wells. Then complete the ELISA analysis according to the manufacturer's instructions.24 hours after irradiating the mice, prepare the human hematopoietic cells for xenograft transplantation. When you resuspend the hematopoietic cells in sterile PBS, it is a good idea to prepare about 15 to 20 percent extra, in case you have a spill during the transplantation. Keep the cells at four degrees Celsius until transplant and transfer the first recipient animal into a warming cage for at least five minutes to facilitate tail-vein dilation.Now warm the cells to room temperature. Gently mix the cell suspension and draw 200 microliters into a tuberculin syringe. Place the mouse in the restrainer and disinfect the tail with isopropyl alcohol.Inject the cells into a lateral tail vein. Then monitor the mouse for at least five minutes to confirm a lack of adverse effects related to the transplant. Patient-derived xenografted, or PDX animals, injected with control stroma consistently demonstrate levels of human thymic stromal lymphopoietin, or TSLP, in mouse plasma that are below the threshold for ELISA detection.The plasma levels of human TSLP in PDX mice injected with TSLP-transduced stroma is proportional to the amount of TSLP stromal cells injected during the previous one to two weeks. Despite being performed in simplicate, this weekly assessment of plasma TSLP levels using the modified ELISA gives results that are, in general, consistent over time. TSLP has been shown to increase the production of normal human B-cell precursors.Indeed, B-lineage cells are significantly increased in TSLP-plus mice compared to the control PDX animals as early as the B-cell precursor stage, suggesting that human TSLP produced in TSLP-plus PDX animals exerts the expected in vivo functional effects on target cell populations. Once optimized, these procedures can generate xenograft mice with detectable levels of human cytokines in three to four weeks. It's important to monitor the cytokine concentration in the stroma cell supernatant over time.This ensures that the cytokine production is sustained in the cytokine-producing stroma and absent in the control stroma. PDX mice can be used for preclinical studies to answer additional questions, such as, How is the efficacy of a specific drug of interest altered by varying the physiological levels of an experimental cytokine of interest in vivo? This innovative model provides a new way for researchers in the fields of hematology and oncology to study the role of TSLP in the development and progression of leukemia, as well as its role in normal hematopoiesis.Provided that you have access to cytokine-transduced cell lines, you can use the techniques demonstrated in this video to supply any exogenous cytokine to patient-derived xenograft disease models using a wide range of immune-deficient mouse strains. Don't forget that working with human hematopoietic cells can be hazardous. You should always use precautions to avoid the transmission of bloodborne pathogens while working with these fluids and cells.

expression-exogenous-cytokine-patient-derived-xenografts-via

Research

JoVE Journal

Medicine

Experimental Generation of Carcinoma-Associated Fibroblasts (CAFs) from Human Mammary Fibroblasts

Carcinomas are complex tissues comprised of neoplastic cells and a non-cancerous compartment referred to as the 'stroma'. The stroma consists of extracellular matrix (ECM) and a variety of mesenchymal cells, including fibroblasts, myofibroblasts, endothelial cells, pericytes and leukocytes 1-3.
The tumour-associated stroma is responsive to substantial paracrine signals released by neighbouring carcinoma cells. During the disease process, the stroma often becomes populated by carcinoma-associated fibroblasts (CAFs) including large numbers of myofibroblasts. These cells have previously been extracted from many different types of human carcinomas for their in vitro culture. A subpopulation of CAFs is distinguishable through their up-regulation of &alpha;-smooth muscle actin (&alpha;-SMA) expression4,5. These cells are a hallmark of 'activated fibroblasts' that share similar properties with myofibroblasts commonly observed in injured and fibrotic tissues 6. The presence of this myofibroblastic CAF subset is highly related to high-grade malignancies and associated with poor prognoses in patients.
Many laboratories, including our own, have shown that CAFs, when injected with carcinoma cells into immunodeficient mice, are capable of substantially promoting tumourigenesis 7-10. CAFs prepared from carcinoma patients, however, frequently undergo senescence during propagation in culture limiting the extensiveness of their use throughout ongoing experimentation. To overcome this difficulty, we developed a novel technique to experimentally generate immortalised human mammary CAF cell lines (exp-CAFs) from human mammary fibroblasts, using a coimplantation breast tumour xenograft model.
In order to generate exp-CAFs, parental human mammary fibroblasts, obtained from the reduction mammoplasty tissue, were first immortalised with hTERT, the catalytic subunit of the telomerase holoenzyme, and engineered to express GFP and a puromycin resistance gene. These cells were coimplanted with MCF-7 human breast carcinoma cells expressing an activated ras oncogene (MCF-7-ras cells) into a mouse xenograft. After a period of incubation in vivo, the initially injected human mammary fibroblasts were extracted from the tumour xenografts on the basis of their puromycin resistance 11.
We observed that the resident human mammary fibroblasts have differentiated, adopting a myofibroblastic phenotype and acquired tumour-promoting properties during the course of tumour progression. Importantly, these cells, defined as exp-CAFs, closely mimic the tumour-promoting myofibroblastic phenotype of CAFs isolated from breast carcinomas dissected from patients. Our tumour xenograft-derived exp-CAFs therefore provide an effective model to study the biology of CAFs in human breast carcinomas. The described protocol may also be extended for generating and characterising various CAF populations derived from other types of human carcinomas.

Experimental Generation of Carcinoma-Associated Fibroblasts CAFs from Human Mammary Fibroblasts

Carcinoma-associated fibroblasts (CAFs) rich in myofibroblasts present within the tumour stroma, play a major role in driving tumour progression. We developed a coimplantation tumour xengraft model for experimentally generating CAFs from human mammary fibroblasts. The protocol describes how to establish CAF myofibroblasts that acquire an ability to promote tumourigenesis.

Carcinomas are complex tissues comprised of neoplastic cells and a non-cancerous compartment referred to as the 'stroma'. The stroma consists of ...

Intraductal Injection of LPS as a Mouse Model of Mastitis: Signaling Visualized via an NF-&kappa;B Reporter Transgenic

Animal models of human disease are necessary in order to rigorously study stages of disease progression and associated mechanisms, and ultimately, as pre-clinical models to test interventions. In these methods, we describe a technique in which lipopolysaccharide (LPS) is injected into the lactating mouse mammary gland via the nipple, effectively modeling mastitis, or inflammation, of the gland. This simulated infection results in increased nuclear factor kappa B (NF-&kappa;B) signaling, as visualized through bioluminescent imaging of an NF-&kappa;B luciferase reporter mouse1.
Our ultimate goal in developing these methods was to study the inflammation associated with mastitis in the lactating gland, which often includes redness, swelling, and immune cell infiltration2,3. Therefore, we were keenly aware that incision or any type of wounding of the skin, the nipple, or the gland in order to introduce the LPS could not be utilized in our methods since the approach would likely confound the read-out of inflammation. We also desired a straight-forward method that did not require specially made hand-drawn pipettes or the use of micromanipulators to hold these specialized tools in place. Thus, we determined to use a commercially available insulin syringe and to inject the agent into the mammary duct of an intact nipple. This method was successful and allowed us to study the inflammation associated with LPS injection without any additional effects overlaid by the process of injection. In addition, this method also utilized an NF-&kappa;B luciferase reporter transgenic mouse and bioluminescent imaging technology to visually and quantitatively show increased NF-&kappa;B signaling within the LPS-injected gland4.
These methods are of interest to researchers of many disciplines who wish to model disease within the lactating mammary gland, as ultimately, the technique described here could be utilized for injection of a number of substances, and is not limited to only LPS.

Intraductal Injection of LPS as a Mouse Model of Mastitis: Signaling Visualized via an NF-&amp;kappa;B Reporter Transgenic

Described here is a technique in which lipopolysaccharide is injected into the lactating mouse mammary gland via the nipple to simulate mastitis, a condition commonly caused by bacterial infection. Lipopolysaccharide injection results in increased nuclear factor kappa B (NF-&kappa;B) signaling, visualized through bioluminescent imaging of an NF-&kappa;B luciferase reporter mouse.

Animal models of human disease are necessary in order to rigorously study stages of disease progression and associated mechanisms, and ultimately, as ...

Patient Derived Cell Culture and Isolation of CD133+ Putative Cancer Stem Cells from Melanoma

Despite improved treatments options for melanoma available today, patients with advanced malignant melanoma still have a poor prognosis for progression-free and overall survival. Therefore, translational research needs to provide further molecular evidence to improve targeted therapies for malignant melanomas. In the past, oncogenic mechanisms related to melanoma were extensively studied in established cell lines. On the way to more personalized treatment regimens based on individual genetic profiles, we propose to use patient-derived cell lines instead of generic cell lines. Together with high quality clinical data, especially on patient follow-up, these cells will be instrumental to better understand the molecular mechanisms behind melanoma progression.
Here, we report the establishment of primary melanoma cultures from dissected fresh tumor tissue. This procedure includes mincing and dissociation of the tissue into single cells, removal of contaminations with erythrocytes and fibroblasts as well as primary culture and reliable verification of the cells' melanoma origin.
Recent reports revealed that melanomas, like the majority of tumors, harbor a small subpopulation of cancer stem cells (CSCs), which seem to exclusively fuel tumor initiation and progression towards the metastatic state. One of the key markers for CSC identification and isolation in melanoma is CD133. To isolate CD133+ CSCs from primary melanoma cultures, we have modified and optimized the Magnetic-Activated Cell Sorting (MACS) procedure from Miltenyi resulting in high sorting purity and viability of CD133+ CSCs and CD133- bulk, which can be cultivated and functionally analyzed thereafter.

Patient Derived Cell Culture and Isolation of CD133+ Putative Cancer Stem Cells from Melanoma

This article describes the preparation of freshly obtained melanoma tissue into primary cell cultures, and how to remove contaminations of erythrocytes and fibroblasts from the tumor cells. Finally, we describe how CD133+ putative melanoma stem cells are sorted from the CD133- bulk using Magnetic Activated Cell Sorting (MACS).

Despite improved treatments options for melanoma available today, patients with advanced malignant melanoma still have a poor prognosis for ...

Minimally Invasive Establishment of Murine Orthotopic Bladder Xenografts

Orthotopic bladder cancer xenografts are the gold standard to study molecular cellular manipulations and new therapeutic agents&#160;in vivo. Suitable cell lines are inoculated either by intravesical instillation (model of nonmuscle invasive growth) or intramural injection into the bladder wall (model of invasive growth). Both procedures are complex and highly time-consuming. Additionally, the superficial model has its shortcomings due to the lack of cell lines that are tumorigenic following instillation. Intramural injection, on the other hand, is marred by the invasiveness of the procedure and the associated morbidity for the host mouse.
With these shortcomings in mind, we modified previous methods to develop a minimally invasive approach for creating orthotopic bladder cancer xenografts. Using ultrasound guidance we have successfully performed percutaneous inoculation of the bladder cancer cell lines UM-UC1, UM-UC3 and UM-UC13 into 50 athymic nude. We have been able to demonstrate that this approach is time efficient, precise and safe. With this technique, initially a space is created under the bladder mucosa with PBS, and tumor cells are then injected into this space in a second step. Tumor growth is monitored at regular intervals with bioluminescence imaging and ultrasound. The average tumor volumes increased steadily in in all but one of our 50 mice over the study period.
In our institution, this novel approach, which allows bladder cancer xenograft inoculation in a minimally-invasive, rapid and highly precise way, has replaced the traditional model.

The established technique to inoculate primary invasive orthotopic bladder cancer xenografts requires laparotomy and mobilization of the bladder. This procedure inflicts significant morbidity on the mice, is technically challenging and time-consuming. We therefore developed a high-precision, percutaneous approach utilizing ultrasound guidance.

Orthotopic bladder cancer xenografts are the gold standard to study molecular cellular manipulations and new therapeutic agents&#160;in vivo. Suitable ...

Ultrasound-guided Transthoracic Intramyocardial Injection in Mice

Murine models of cardiovascular disease are important for investigating pathophysiological mechanisms and exploring potential regenerative therapies. Experiments involving myocardial injection are currently performed by direct surgical access through a thoracotomy. While convenient when performed at the time of another experimental manipulation such as coronary artery ligation, the need for an invasive procedure for intramyocardial delivery limits potential experimental designs. With ever improving ultrasound resolution and advanced noninvasive imaging modalities, it is now feasible to routinely perform ultrasound-guided, percutaneous intramyocardial injection. This modality efficiently and reliably delivers agents to a targeted region of myocardium. Advantages of this technique include the avoidance of surgical morbidity, the facility to target regions of myocardium selectively under ultrasound guidance, and the opportunity to deliver injectate to the myocardium at multiple, predetermined time intervals. With practiced technique, complications from intramyocardial injection are rare, and mice quickly return to normal activity on recovery from anesthetic. Following the steps outlined in this protocol, the operator with basic echocardiography experience can quickly become competent in this versatile, minimally invasive technique.

Echocardiography-guided percutaneous intramyocardial injection represents an efficient, reliable, and targetable modality for the delivery of gene transfer agents or cells into the murine heart. Following the steps outlined in this protocol, the operator can quickly become competent in this versatile, minimally invasive technique.

Murine models of cardiovascular disease are important for investigating pathophysiological mechanisms and exploring potential regenerative therapies. ...

Assessment of Viability of Human Fat Injection into Nude Mice with Micro-Computed Tomography

Lipotransfer is a vital tool in the surgeon&#8217;s armamentarium for the treatment of soft tissue deficits of throughout the body. Fat is the ideal soft tissue filler as it is readily available, easily obtained, inexpensive, and inherently biocompatible.1 However, despite its burgeoning popularity, fat grafting is hampered by unpredictable results and variable graft survival, with published retention rates ranging anywhere from 10-80%. 1-3
To facilitate investigations on fat grafting, we have therefore developed an animal model that allows for real-time analysis of injected fat volume retention. Briefly, a small cut is made in the scalp of a CD-1 nude mouse and 200-400 &#181;l&#160;of processed lipoaspirate is placed over the skull. The scalp is chosen as the recipient site because of its absence of native subcutaneous fat, and because of the excellent background contrast provided by the calvarium, which aids in the analysis process. Micro-computed tomography (micro-CT) is used to scan the graft at baseline and every two weeks thereafter. The CT images are reconstructed, and an imaging software is used to quantify graft volumes.
Traditionally, techniques to assess fat graft volume have necessitated euthanizing the study animal to provide just a single assessment of graft weight and volume by physical measurement ex vivo. Biochemical and histological comparisons have likewise required the study animal to be euthanized. This described imaging technique offers the advantage of visualizing and objectively quantifying volume at multiple time points after initial grafting without having to sacrifice the study animal. The technique is limited by the size of the graft able to be injected as larger grafts risk skin and fat necrosis. This method has utility for all studies evaluating fat graft viability and volume retention. It is particularly well-suited to providing a visual representation of fat grafts and following changes in volume over time.

Fat grafting is an essential technique for reconstructing soft tissue deficits. However, it remains an unpredictable procedure characterized by variable graft survival. Our goal was to devise a mouse model that utilizes a novel imaging method to compare volume retention between differing techniques of fat graft preparation and delivery.

Lipotransfer is a vital tool in the surgeon&#8217;s armamentarium for the treatment of soft tissue deficits of throughout the body. Fat is the ideal soft ...

Isolation and Immortalization of Patient-derived Cell Lines from Muscle Biopsy for Disease Modeling

The generation of patient-specific cell lines represents an invaluable tool for diagnostic or translational research, and these cells can be collected from skin or muscle biopsy tissue available during the patient&#8217;s diagnostic workup. In this protocol, we describe a technique for live cell isolation from small amounts of muscle or skin tissue for primary cell culture. Additionally, we provide a technique for the immortalization of myogenic cell lines and fibroblast cell lines from primary cells. Once cell lines are immortalized, substantial expansion of patient-derived cells can be achieved. Immortalized cells are amenable to many downstream applications, including drug screening and in vitro correction of the genetic mutation. Altogether, these protocols provide a reliable tool to generate and preserve patient-derived cells for downstream applications.

This protocol describes techniques for live cell isolation and primary culture of myogenic and fibroblast cell lines from muscle or skin tissue. A technique for the immortalization of these cell lines is also described. Altogether, these protocols provide a reliable tool to generate and preserve patient-derived cells for downstream applications.

The generation of patient-specific cell lines represents an invaluable tool for diagnostic or translational research, and these cells can be collected ...

Generation of Prostate Cancer Patient Derived Xenograft Models from Circulating Tumor Cells

Patient derived xenograft (PDX) models are gaining popularity in cancer research and are used for preclinical drug evaluation, biomarker identification, biologic studies, and personalized medicine strategies. Circulating tumor cells (CTC) play a critical role in tumor metastasis and have been isolated from patients with several tumor types. Recently, CTCs have been used to generate PDX experimental models of breast and prostate cancer. This manuscript details the method for the generation of prostate cancer PDX models from CTCs developed by our group. Advantages of this method over conventional PDX models include independence from surgical sample collection and generating experimental models at various disease stages. Density gradient centrifugation followed by red blood cell lysis and flow cytometry depletion of CD45 positive mononuclear cells is used to enrich CTCs from peripheral blood samples collected from patients with metastatic disease. The CTCs are then injected into immunocompromised mice; subsequently generated xenografts can be used for functional studies or harvested for molecular characterization. The primary limitation of this method is the negative selection method used for CTC enrichment. Despite this limitation, the generation of PDX models from CTCs provides a novel experimental model to be applied to prostate cancer research.

This manuscript details a method used to generate prostate cancer patient derived xenografts (PDXs) from circulating tumor cells (CTCs). The generation of PDX models from CTCs provides an alternative experimental model to study prostate cancer; the most commonly diagnosed tumor and a frequent cause of death from cancer in men.

Patient derived xenograft (PDX) models are gaining popularity in cancer research and are used for preclinical drug evaluation, biomarker identification, ...

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic patient tumors in different assays1. Human tumor xenografts represent the gold standard with respect to tumor biology, drug discovery, and metastasis research 2-4. Tumor xenografts can be derived from different types of material like tumor cell lines, tumor tissue from primary patient tumors4 or serially transplanted tumors. When propagated in vivo, xenografted tissue is infiltrated and vascularized by cells of mouse origin. Multiple factors such as the tumor entity, the origin of xenografted material, growth rate and region of transplantation influence the composition and the amount of mouse cells present in tumor xenografts. However, even when these factors are kept constant, the degree of mouse cell contamination is highly variable.
Contaminating mouse cells significantly impair downstream analyses of human tumor xenografts. As mouse fibroblasts show high plating efficacies and proliferation rates, they tend to overgrow cultures of human tumor cells, especially slowly proliferating subpopulations. Mouse cell derived DNA, mRNA, and protein components can bias downstream gene expression analysis, next-generation sequencing, as well as proteome analysis 5. To overcome these limitations, we have developed a fast and easy method to isolate untouched human tumor cells from xenografted tumor tissue. This procedure is based on the comprehensive depletion of cells of mouse origin by combining automated tissue dissociation with the benchtop tissue dissociator and magnetic cell sorting. Here, we demonstrate that human target cells can be can be obtained with purities higher than 96% within less than 20 min independent of the tumor type.

Human tumor xenografts are vascularized and infiltrated by cells of mouse origin during the growth phase in vivo. To circumvent the bias caused by these contaminating cells during downstream analysis, we developed a method allowing for comprehensive depletion of all mouse cells by magnetic cell sorting.

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic ...

Full-root Aortic Valve Replacement by Stentless Aortic Xenografts in Patients with Small Aortic Roots

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial valve might not meet the functional needs. The implantation of a too-small stented pericardial valve, leading to an effective orifice area indexed to a body surface area less than 0.85 cm2/m2, is regarded as prosthesis-patient mismatch (PPM). A PPM negatively affects the regression of left ventricular hypertrophy and thus the normalization of left ventricular function and the alleviation of symptoms. Persistent left ventricular hypertrophy is associated with an increased risk of arrhythmias and sudden cardiac death. In the case of predictable PPM, there are three options: 1) accept the PPM resulting from the implantation of a stented pericardial valve when comorbidities of the patient forbid the more technically demanding operative technique of implanting a larger prosthesis, 2) enlarge the aortic root to accommodate a larger stented valve substitute, or 3) implant a stentless biological valve or a homograft. Compared to classical aortic valve replacement with stented pericardial valves, the full-root implantation of stentless aortic xenografts offers the possibility of implanting a 3-4 mm larger valve in a given patient, thus allowing significant reduction in transvalvular gradients. However, a number of cardiac surgeons are reluctant to transform a classical aortic valve replacement with stented pericardial valves into the more technically challenging full-root implantation of stentless aortic xenografts. Given the potential hemodynamic advantages of stentless aortic xenografts, we have adopted full-root implantation to avoid PPM in patients with small aortic roots necessitating an aortic valve replacement. Here, we describe in detail a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses. Limitations of this technique and alternative options are discussed.

Full-root aortic valve replacement by stentless aortic xenograft is a viable option in patients with small aortic roots. We describe, a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses, and discuss its limitations and alternative options.

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial ...