This work was funded by the Institut Pasteur, the Bettencourt-Schueller foundation, Centre National de la Recherche Scientifique, University Paris Diderot, Agence Nationale de la Recherche (ANR-13-SAMA-0006; SynDivAutism), the Conny-Maeva Charitable Foundation, the Cognacq Jay Foundation, the Orange Foundation, and the Fondamental Foundation. L.G. is supported by an undergraduate fellowship from the Health Ministry. We acknowledge the help of BitPlane in particular Georgia Golfis, in the early stage of this work.

1. Neuronal Culture
Note: Fibroblast reprogramming in pluripotent stem cells, commitment to the dorsal telencephalon lineage, derivation, amplification, and banking of late cortical progenitors (LCP) were described in Boissart et al4. Neuronal differentiation of LCP-like cells was also performed according to Boissart et al4 with slight modifications. Other procedures have been developed for direct reprogramming of fibroblasts into induced&#160;pluripotent stem cells followed by their differentiation into neurons. This protocol was retained since it allows the selective production of pyramidal glutamatergic neurons.
<ol>
	<li>Treat 6-well culture plates with glass coverslips with poly-ornithine (diluted to 1/6 in DPBS, stock concentration 0.01%) O/N, followed by three washes in DPBS. Then add laminin (stock concentration 1 mg/ml, diluted 500 times in DPBS) for at least 10 hr under the flow hood.</li>
	<li>Plate and dispatch NSC at low density (50,000 cells/cm2) in 6-well culture plates with glass coverslips in 3 ml of culture medium consisting of DMEM/F12 (500 ml), 2 vials (5 ml each) of N2 supplement, 2 vials (10 ml each) of B27 supplement, 10 ml of Pen-Streptomycin (Penicillin = 10,000 units/ml and Streptomycin = 10,000 units/ml), 1 ml of 2-mercaptoethanol (Stock solution: 50 mM) and laminin (1/500), without growth factors. CRITICAL STEP: Carry out this step carefully by adding cells with slow rotating movements in order to reduce cell clustering.</li>
	<li>Remove the culture medium. Add fresh N2B27 medium containing 2 &#181;g/ml of fresh laminin solution to keep the neuron attached on the glass coverslips and avoid clumping. Change the medium every 3 days. Keep some of the remaining medium (200 &#181;l) before adding fresh medium in order to prevent the cell from drying. Alternatively, proceed rapidly and change the total volume (3 ml).</li>
</ol>
2. Lentiviral Transduction
Note: GFP lentiviral vectors were kindly provided by Dr. Uwe Maskos Laboratory at Institut Pasteur (Paris) and prepared according to the published protocol 5. GFP expression is driven by the mouse phosphoglycerate kinase (PGK) promoter. For this study, viral titer was of 400 ng/&#181;l (stock solution in PBS 1x).
<ol>
	<li>Transduce human iPSC-derived neurons at any step of maturation by viral particles by adding 1 &#181;l of the stock solution containing 40 ng of GFP lentiviral vector per culture well (6-well plates) and incubate for 48 hr in fresh culture medium. Note: For this protocol, the duration of incubation allows a good labeling of spine structures.</li>
</ol>
3. Immunofluorescence
Note: In order to improve the labeling of the whole spine morphology, immunofluorescence labeling was performed using an anti-GFP antibody in permeabilized conditions.
<ol>
	<li>Remove culture medium and fix transduced cells on coverslips in 4% paraformaldehyde for 10 min at RT, then wash 3 times in 1x&#160;PBS (10 min each).</li>
	<li>Immerge coverslips in PBS supplemented with 0.05% Triton (100x) and 10% horse serum for 1 hr at RT, then wash 3 times in 1x&#160;PBS.</li>
	<li>Add 100 &#181;l of 1x PBS supplemented with 4% horse serum and primary antibody (1/1,000) raised against GFP and diluted by a factor of 1,000 on each coverslip. Incubate in a dark box O/N at 4&#176;C, then wash 3 times with 1x PBS.</li>
	<li>Dilute Alexa Fluor 488-conjugated antibody (1/200) in PBS supplemented with 0.5% of Tween 20 and incubate for 1 hr at RT. Then wash 3 times in 1x PBS and mount coverslips on glass slides with mounting medium for fluorescence microscopy.</li>
</ol>
4. Dendritic Spine Imaging
<ol>
	<li>Perform confocal Imaging through a confocal laser-scanning microscope.</li>
	<li>Select healthy neurons with pyramidal morphology and a full dendritic arborization, and quantify at least 10 neurons per condition from separate experiments. Quantify 60 - 100 &#181;m per dendrite.</li>
	<li>Acquire images using a 40X oil NA = 1.3 objective and a 488&#160;nm laser line for GFP excitation, with a typical peak power at sample level around 20&#160;&#181;W. Set pixel size around 80&#160;nm to properly sample dendritic spines. 
	Note: The subsequent analysis call for an image in which the noise does not compromise the proper segmentation of dendrites and spines. With the spatial sampling and power settings mentioned above, we observed that a pixel dwell-time of 3.15&#160;&#181;s is sufficient to collect enough photons to build such an image. For dim samples, image quality can be improved by averaging 2 to 4 scans. The acquisition of several XY tiles may be needed to cover the region of interest, which then must be stitched together before processing.</li>
	<li>To sample the whole neuron volume, acquire a Z-stack, with a Z spacing ranging from 150&#160;nm to 300&#160;nm, yielding 20 to 30 Z slices. 
	Note: The lateral spatial resolution achieved with these settings is 234 nm and the axial resolution is 591 nm. The sampling chosen here is adequate, but as the axial resolution is larger than the smallest size of the spines to be imaged, the analysis favors the spines that extend laterally from the dendrites. 
	&#160;</li>
</ol>
5. 3D Quantification of Dendritic Spines
Note: The following sections specifically describe the use of the Imaris software for analysis. Alternative implementations exist, including NeuronStudio15 or Metamorph8, which can provide similar results.
Use the following key settings:
<ol>
	<li>As a pre-processing stage, use Gaussian filtering through the image processing facilities offered by the software. Perform Gaussian filtering via the Image Processing &#62; Smoothing &#62; Gaussian Filter. Set the filter width to be equal to the pixel size in XY.</li>
	<li>Perform a Semi-automatic tracing of dendrites, using the Filament Tracer module of the software.
	<ol>
		<li>First, estimate the dendrite diameter, by using the distance tool in the Slice&#160;tab of the software.&#160;</li>
		<li>In the Surpass&#160;tab, click on the Filaments tool. For a better robustness, this protocol relies on semi-automated tracking; click on Skip automatic creation. The module interface is now showing the Draw&#160;tab.&#160;Here, select AutoPath&#160;as a method, Dendrite as a type,&#160;and input the estimated dendrite diameter.</li>
		<li>Use the Select&#160;mode of the pointer, turning the cursor into a box. Shift-right-click on the dendrite starting point. Note: the software performs initial calculations.</li>
		<li>Move the pointer along the dendrite. From the starting point (represented as a blue sphere), a yellow line representing the most likely dendrite path is shown. Shift-left-click on the dendrite endpoint.</li>
	</ol>
	</li>
	<li>Perform the automated spines segmentation. Note: The spines on the traced dendrite are to be found automatically by the module interface.&#160;
	<ol>
		<li>In the module interface, click on the Creation&#160;tab. In the Rebuild&#160;drop-list, pick Rebuild Dendrite Diameter&#160;and check the Keep data&#160;box. Then click Rebuild.</li>
		<li>Set the Threshold&#160;so that the segmented volume corresponds to the actual dendrite volume. As an Algorithm, select Shortest Distance from Distance Map.&#160;Click the Next button.</li>
		<li>Determine the smallest spine head diameter and the maximal length, again by using the distance tool in the&#160;Slice&#160;tab of the software, then come back to the Surpass tab and enter the parameters. For this protocol,&#160;values around 200 - 300&#160;nm for minimal diameter and 4&#160;&#181;m for maximal length are good starting points.&#160;Do not check the Allow Branch Spines&#160;box.&#160;Click the&#160;Next&#160;button.</li>
		<li>Adjust the Seed Points Threshold&#160;so that the blue points representing spines localize to actual spine heads.&#160;Click the&#160;Next&#160;button. Note: The core calculation is done now and can be lengthy.</li>
	</ol>
	</li>
	<li>Classify spines by going to the Tools tab of the module interface. Click on Classify Spines. In the prompted user interface, make sure that there are four classes, defined by their morphology as follows: Stubby: length&#160;&#60;1 &#181;m; Mushroom: Length (spine) &#62;3 and Max width (head) &#62;mean width (neck) x&#160;2; Long thin: Mean width (head) &#8805;&#160;Mean width (neck); Filopodia-like: Length &#8804;&#160;4 &#181;m (no head). &#160; 
	Note: The module interface generates four new Filament objects containing the results of the classification.&#160;</li>
	<li>Export Statistical data: on any of these four object interfaces, go to the Statistics tab.&#160; 
	Click on the Export All Statistics to File&#160;button. 
	Note: Other statistical values can be exported for dendrites (e.g., length, area, mean diameter, branch depth, branching angle, volume, etc.), and for spines (e.g.,&#160;straightness, area of attachment, length and volume of distinct spine parts, spine diameter, densities, etc.)</li>
</ol>

<ol>
	<li>Durand, C., 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=SHANK3+mutations+identified+in+autism+led+to+modification+of+dendritic+spine+morphology+via+an+actin-dependent+mechanism.">SHANK3 mutations identified in autism led to modification of dendritic spine morphology via an actin-dependent mechanism.</a> Molecular Psychiatry. 17 (1), 71-84 (2013).</li><li>Arenallo, J. I., Espinosa, A., Fairen, A., Yuste, R., Defelipe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-synaptic+dendritic+spines+in+neocortex.">Non-synaptic dendritic spines in neocortex.</a> Neuroscience. 145, 464-469 (2007).</li><li>Benavides-Piccione, R., Fernaud-Espinosa, I., Robles, V., Yuste, R., DeFelipe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age-based+comparison+of+human+dendritic+spine+structure+using+complete+three-dimensional+reconstructions.">Age-based comparison of human dendritic spine structure using complete three-dimensional reconstructions.</a> Cerebral Cortex. 23 (8), 1798-1810 (2013).</li><li>Boissart, C., 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=Differentiation+from+human+pluripotent+stem+cells+of+cortical+neurons+of+the+superficial+layers+amenable+to+psychiatric+disease+modeling+and+high-throughput+drug+screening.">Differentiation from human pluripotent stem cells of cortical neurons of the superficial layers amenable to psychiatric disease modeling and high-throughput drug screening.</a> Translational Psychiatry. 3, 1-11 (2013).</li><li>Avale, M. E., 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=Interplay+of+beta+2*+nicotinic+receptors+and+dopamine+pathways+in+the+control+of+spontaneous+locomotion.">Interplay of beta 2* nicotinic receptors and dopamine pathways in the control of spontaneous locomotion.</a> Proceedings of National Academy of Science USA. 105 (41), 15991-15996 (2008).</li><li>Xie, Z., 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=Coordination+of+synaptic+adhesion+with+dendritic+spine+remodeling+by+AF6+and+kalirin-7.">Coordination of synaptic adhesion with dendritic spine remodeling by AF6 and kalirin-7.</a> Journal of Neuroscience. 28 (24), 6079-6091 (2008).</li><li>Srivastava, D. P., 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=Afadin+is+required+for+maintenance+of+dendritic+structure+and+excitatory+tone.">Afadin is required for maintenance of dendritic structure and excitatory tone.</a> Journal of Biological Chemistry. 287 (43), 35964-35974 (2012).</li><li>Srivastava, D. P., Woolfrey, K. M., Penzes, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+dendritic+spine+morphology+in+cultured+CNS+neurons.">Analysis of dendritic spine morphology in cultured CNS neurons.</a> Journal of Visualized Experiments. (53), e2794 (2011).</li><li>Brennand, K. J., Gage, F. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+psychiatric+disorders+through+reprogramming.">Modeling psychiatric disorders through reprogramming.</a> Disease Models and Mechanisms. 5 (1), 26-32 (2012).</li><li>Kim, S. S., Ross, P. 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The authors have nothing to disclose.

The quantification of the morphological features of pyramidal neurons relied on the software. The Filament Tracer interface was used for segmentation of neurons and spines, and the XT module was used for their analysis.
To analyze the accuracy of our technique, we first compared the measured morphologic parameters (length, area, and total spine volume when applicable), with those published using rat mature pyramidal neurons in culture 6, 7 and human brain tissues 3. Densi...

Dendritic spines of cortical pyramidal neurons are small and thin protrusions which are distributed along the basal and apical dendrites of these neuronal subtypes in rodent, primate, and human brain. They are the sites of most excitatory synapses and display key functions in learning and cognitive processes. The detailed structures of human dendritic spines have been technically studied by electron microscopy 2. However, such approach is time-consuming and represents heavy workload. More recently, a three-dimensional (3D) reconstruction of the morphology of dendritic spines has been reported in human brain cortex using specific software combined to large manual spine analysis3.
Green fluorescence protein (GFP) technology coupled to immunofluorescence represents an accurate tool for spine identification and shape measurement by fluorescence microscopy. This approach can be easily applied to cultured neurons. However, no data have been reported on the analysis of spine maturation and morphology on human neurons derived from induced&#160;pluripotent stem cells (iPSC).
The objective of this study was to describe a protocol, which allows dendritic spine imaging from cultured human neurons in vitro. GFP labeling, confocal microscopy and 3D analysis with the Filament Tracer module of Imaris software were used in the present protocol. Culture steps that are necessary to obtain cortical glutamatergic neurons of layers II to IV from neural stem cells (NSC) are also briefly described here.&#160;The entire protocol for human NSC production has already been published elsewhere 4.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>PD-PBS (1X), sans Calcium, Magnesium et Phenol Red</td>
			<td>Gibco/ Life Technologies</td>
			<td>14190169</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly-L-Ornithine Solution Bioreagent</td>
			<td>Sigma Aldrich</td>
			<td>P4957</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse laminin</td>
			<td>Dutscher Dominique</td>
			<td>354232</td>
			<td></td>
		</tr>
		<tr>
			<td>N2 Supplement</td>
			<td>Gibco/ Life Technologies</td>
			<td>17502048</td>
			<td></td>
		</tr>
		<tr>
			<td>B-27 Supplement w/o vit A (50X)</td>
			<td>Gibco/ Life Technologies</td>
			<td>12587010</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM/NUT.MIX F-12 W/GLUT-I</td>
			<td>Gibco/ Life Technologies</td>
			<td>31331028</td>
			<td></td>
		</tr>
		<tr>
			<td>Neurobasal Med SFM</td>
			<td>Gibco/ Life Technologies</td>
			<td>21103049</td>
			<td></td>
		</tr>
		<tr>
			<td>2-mercaptoethanol</td>
			<td>Gibco/ Life Technologies</td>
			<td>31350-010</td>
			<td></td>
		</tr>
		<tr>
			<td>Pen-Steptomycin</td>
			<td>Gibco/ Life Technologies</td>
			<td>15140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>GFP Rabbit Serum Polyclonal Antibody</td>
			<td>Gibco/ Life Technologies</td>
			<td>A-6455</td>
			<td></td>
		</tr>
		<tr>
			<td>Horse serum</td>
			<td>Gibco/ Life Technologies</td>
			<td>16050130</td>
			<td></td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 Goat Anti-Rabbit&#160;</td>
			<td>Gibco/ Life Technologies</td>
			<td>A11034</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyclonal Anti-betaIII tubulin antibody</td>
			<td>Millipore</td>
			<td>AB9354</td>
			<td></td>
		</tr>
		<tr>
			<td>Coverglass 13 mm</td>
			<td>VWR</td>
			<td>631-0150</td>
			<td></td>
		</tr>
		<tr>
			<td>Prolong Gold Antifade Reagent avec DAPI</td>
			<td>Gibco/ Life Technologies</td>
			<td>P36931</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween(R) 20 Bioextra, Viscous Liquid</td>
			<td>Sigma Aldrich Chimie</td>
			<td>P7949</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma Aldrich Chimie</td>
			<td>X100-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Human Fibroblasts</td>
			<td>Coriell Cell Line Biorepository</td>
			<td>GM 4603 and GM 1869</td>
			<td>Coriell Institute for Medical Research, Camden, NJ, USA</td>
		</tr>
		<tr>
			<td>Confocal laser scanning microscope</td>
			<td>Zeiss (Germany)</td>
			<td>LSM 700</td>
			<td></td>
		</tr>
		<tr>
			<td>Imaris Software</td>
			<td>Bitplane AG, Zurich</td>
			<td>6.4.0 version</td>
			<td>Filament Tracer and Imaris XT modules are necessary</td>
		</tr>
		<tr>
			<td>Huygens Software</td>
			<td>Huygens software, SVI, Netherlands</td>
			<td>Pro version</td>
			<td>Optional (for deconvolution testing)</td>
		</tr>
	</tbody>
</table>

three-dimensional quantification of dendritic spines from pyramidal neurons derived from human induced pluripotent stem cells

Dendritic spines are small protrusions that correspond to the post-synaptic compartments of excitatory synapses in the central nervous system. They are distributed along the dendrites. Their morphology is largely dependent on neuronal activity, and they are dynamic. Dendritic spines express glutamatergic receptors (AMPA and NMDA receptors) on their surface and at the levels of postsynaptic densities. Each spine allows the neuron to control its state and local activity independently. Spine morphologies have been extensively studied in glutamatergic pyramidal cells of the brain cortex, using both in vivo approaches and neuronal cultures obtained from rodent tissues. Neuropathological conditions can be associated to altered spine induction and maturation, as shown in rodent cultured neurons and one-dimensional quantitative analysis 1. The present study describes a protocol for the 3D quantitative analysis of spine morphologies using human cortical neurons derived from neural stem cells (late cortical progenitors). These cells were initially obtained from induced&#160;pluripotent stem cells. This protocol allows the analysis of spine morphologies at different culture periods, and with possible comparison between induced&#160;pluripotent stem cells obtained from control individuals with those obtained from patients with psychiatric diseases.

The present study describes a standardized protocol for spine quantification of cultured dendrites of pyramidal neurons derived from iPSC. This protocol allows the analysis of spine maturation on human neurons and its possible comparison with the maturation of spines in standard rodent neuronal cultures as well as in in vivo animal models.
Figure 1A represents a scheme of the different steps of culture which allow the production of cortical pyramidal neurons. Such sch...

Watch this Scientific Journal Video about Three-dimensional Quantification of Dendritic Spines from Pyramidal Neurons Derived from Human Induced Pluripotent Stem Cells at JoVE.com

Three-dimensional Quantification of Dendritic Spines from Pyramidal Neurons Derived from Human Induced Pluripotent Stem Cells

Dendritic spines of pyramidal neurons are the sites of most excitatory synapses in mammalian brain cortex. This method describes a 3D quantitative analysis of spine morphologies in human cortical pyramidal glutamatergic neurons derived from induced&#160;pluripotent stem cells.

Dendritic spines are small protrusions that correspond to the post-synaptic compartments of excitatory synapses in the central nervous system. They are ...

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11.3K Views.  Institut Pasteur. Dendritic spines of pyramidal neurons are the sites of most excitatory synapses in mammalian brain cortex. This method describes a 3D quantitative analysis of spine morphologies in human cortical pyramidal glutamatergic neurons derived from induced pluripotent stem cells.

Video: Three-dimensional Quantification of Dendritic Spines from Pyramidal Neurons Derived from Human Induced Pluripotent Stem Cells

Generation of Integration-free Human Induced Pluripotent Stem Cells Using Hair-derived Keratinocytes

Recent advances in reprogramming allow us to turn somatic cells into human induced pluripotent stem cells (hiPSCs). Disease modeling using patient-specific hiPSCs allows the study of the underlying mechanism for pathogenesis, also providing a platform for the development of in vitro drug screening and gene therapy to improve treatment options. The promising potential of hiPSCs for regenerative medicine is also evident from the increasing number of publications (>7000) on iPSCs in recent years. Various cell types from distinct lineages have been successfully used for hiPSC generation, including skin fibroblasts, hematopoietic cells and epidermal keratinocytes. While skin biopsies and blood collection are routinely performed in many labs as a source of somatic cells for the generation of hiPSCs, the collection and subsequent derivation of hair keratinocytes are less commonly used. Hair-derived keratinocytes represent a non-invasive approach to obtain cell samples from patients. Here we outline a simple non-invasive method for the derivation of keratinocytes from plucked hair. We also provide instructions for maintenance of keratinocytes and subsequent reprogramming to generate integration-free hiPSC using episomal vectors.

This manuscript provides a step-by-step procedure for the derivation and maintenance of human keratinocytes from plucked hair and subsequent generation of integration-free human induced pluripotent stem cells (hiPSCs) by episomal vectors.

Recent advances in reprogramming allow us to turn somatic cells into human induced pluripotent stem cells (hiPSCs). Disease modeling using ...

Feeder-free Derivation of Melanocytes from Human Pluripotent Stem Cells

Human pluripotent stem cells (hPSCs) represent a platform to study human development in vitro under both normal and disease conditions. Researchers can direct the differentiation of hPSCs into the cell type of interest by manipulating the culture conditions to recapitulate signals seen during development. One such cell type is the melanocyte, a pigment-producing cell of neural crest (NC) origin responsible for protecting the skin against UV irradiation. This protocol presents an extension of a currently available in vitro Neural Crest differentiation protocol from hPSCs to further differentiate NC into fully pigmented melanocytes. Melanocyte precursors can be enriched from the Neural Crest protocol via a timed exposure to activators of WNT, BMP, and EDN3 signaling under dual-SMAD-inhibition conditions. The resultant melanocyte precursors are then purified and matured into fully pigmented melanocytes by culture in a selective medium. The resultant melanocytes are fully pigmented and stain appropriately for proteins characteristic of mature melanocytes.

This work describes an in vitro differentiation protocol to produce pigmented, mature melanocytes from human pluripotent stem cells via a neural crest and melanoblast intermediate stage using a feeder-free, 25 day protocol.

Human pluripotent stem cells (hPSCs) represent a platform to study human development in vitro under both normal and disease conditions. Researchers can ...

Generation of Induced Pluripotent Stem Cells from Human Melanoma Tumor-infiltrating Lymphocytes

Adoptive transfer of ex vivo expanded autologous tumor-infiltrating lymphocytes (TILs) can mediate durable and complete responses in significant subsets of patients with metastatic melanoma. Major obstacles of this approach are the reduced viability of transferred T cells, caused by telomere shortening, and the limited number of TILs obtained from patients. Less-differentiated T cells with long telomeres would be an ideal T cell subset for adoptive T cell therapy;however, generating large numbers of these less-differentiated T cells is problematic. This limitation of adoptive T cell therapy can be theoretically overcome by using induced pluripotent stem cells (iPSCs) that self-renew, maintain pluripotency, have elongated telomeres, and provide an unlimited source of autologous T cells for immunotherapy. Here, we present a protocol to generate iPSCs using Sendai virus vectors for the transduction of reprogramming factors into TILs. This protocol generates fully reprogrammed, vector-free clones. These TIL-derived iPSCs might be able to generate less-differentiated patient- and tumor-specific T cells for adoptive T cell therapy.

The goal of this protocol is to show the protocol for reprogramming melanoma tumor-infiltrating lymphocytes into induced pluripotent stem cells.

Adoptive transfer of ex vivo expanded autologous tumor-infiltrating lymphocytes (TILs) can mediate durable and complete responses in significant subsets ...

Generation of Integration-free Induced Pluripotent Stem Cells from Human Peripheral Blood Mononuclear Cells Using Episomal Vectors

Induced Pluripotent Stem Cells (iPSCs) hold great promise for disease modeling and regenerative therapies. We previously reported the use of Episomal Vectors (EV) to generate integration-free iPSCs from peripheral blood mononuclear cells (PB MNCs). The episomal vectors used are DNA plasmids incorporated with oriP and EBNA1 elements from the Epstein-Barr (EB) virus, which&#160;allow for replication and long-term retainment of plasmids in mammalian cells, respectively. With further optimization, thousands of iPSC colonies can be obtained from 1 mL of peripheral blood. Two critical factors for achieving high reprogramming efficiencies&#160;are: 1) the use of a 2A &#34;self-cleavage&#34; peptide to link OCT4 and SOX2, thus achieving equimolar expression of the two factors; 2) the use of two vectors to express MYC and KLF4 individually. Here we describe a step-by-step protocol for generating integration-free iPSCs from adult peripheral blood samples. The generated iPSCs are integration-free as residual episomal plasmids are undetectable after five passages. Although the reprogramming efficiency is comparable to that of Sendai Virus (SV) vectors, EV plasmids are considerably more economical than the commercially available SV vectors. This affordable EV reprogramming system holds potential for clinical applications in regenerative medicine and provides an approach for the direct reprogramming of PB MNCs to integration-free mesenchymal stem cells, neural stem cells, etc.

This protocol describes a detailed method for efficient generation of integration-free iPSCs from human adult peripheral blood cells. With the use of four oriP/EBNA-based episomal vectors to express the reprogramming factors, KLF4, MYC, BCL-XL, or OCT4 and SOX2, thousands of iPSC colonies can be obtained from 1 mL of peripheral blood.

Induced Pluripotent Stem Cells (iPSCs) hold great promise for disease modeling and regenerative therapies. We previously reported the use of Episomal ...

Differentiating Chondrocytes from Peripheral Blood-derived Human Induced Pluripotent Stem Cells

In this study, we used peripheral blood cells (PBCs) as seed cells to produce chondrocytes via induced pluripotent stem cells (iPSCs) in an integration-free method. Following embryoid body (EB) formation and fibroblastic cell expansion, the iPSCs are induced for chondrogenic differentiation for 21 days under serum-free and xeno-free conditions. After chondrocyte induction, the phenotypes of the cells are evaluated by morphological, immunohistochemical, and biochemical analyses, as well as by the quantitative real-time PCR examination of chondrogenic differentiation markers. The chondrogenic pellets show positive alcian blue and toluidine blue staining. The immunohistochemistry of collagen II and X staining is also positive. The sulfated glycosaminoglycan (sGAG) content and the chondrogenic differentiation markers COLLAGEN 2 (COL2), COLLAGEN 10 (COL10), SOX9, and AGGRECAN are significantly upregulated in chondrogenic pellets compared to hiPSCs and fibroblastic cells. These results suggest that PBCs can be used as seed cells to generate iPSCs for cartilage repair, which is patient-specific and cost-effective.

We present a protocol to generate a chondrogenic lineage from human peripheral blood (PB) via induced pluripotent stem cells (iPSCs) using an integration-free method, which includes embryoid body (EB) formation, fibroblastic cells expansion, and chondrogenic induction.

In this study, we used peripheral blood cells (PBCs) as seed cells to produce chondrocytes via induced pluripotent stem cells (iPSCs) in an ...

Chondrogenic Pellet Formation from Cord Blood-derived Induced Pluripotent Stem Cells

Human articular cartilage lacks the ability to repair itself. Cartilage degeneration is thus treated not by curative but by conservative treatments. Currently, efforts are being made to regenerate damaged cartilage with ex vivo expanded chondrocytes or bone marrow-derived mesenchymal stem cells (BMSCs). However, the restricted viability and instability of these cells limit their application in cartilage reconstruction. Human induced pluripotent stem cells (hiPSCs) have received scientific attention as a new alternative for regenerative applications. With unlimited self-renewal ability and multipotency, hiPSCs have been highlighted as a new replacement cell source for cartilage repair. However, obtaining a high quantity of high-quality chondrogenic pellets is a major challenge to their clinical application. In this study, we used embryoid body (EB)-derived outgrowth cells for chondrogenic differentiation. Successful chondrogenesis was confirmed by PCR and staining with alcian blue, toluidine blue, and antibodies against collagen types I and II (COL1A1 and COL2A1, respectively). We provide a detailed method for the differentiation of cord blood mononuclear cell-derived iPSCs (CBMC-hiPSCs) into chondrogenic pellets.

Here, we propose a protocol for chondrogenic differentiation from cord blood mononuclear cell-derived human induced pluripotent stem cells.

Human articular cartilage lacks the ability to repair itself. Cartilage degeneration is thus treated not by curative but by conservative treatments. ...

Rapid, Directed Differentiation of Retinal Pigment Epithelial Cells from Human Embryonic or Induced Pluripotent Stem Cells

We describe a robust method to direct the differentiation of pluripotent stem cells into retinal pigment epithelial cells (RPE). The purpose of providing a detailed and thorough protocol is to clearly demonstrate each step and to make this readily available to researchers in the field. This protocol results in a homogenous layer of RPE with minimal or no manual dissection needed. The method presented here has been shown to be effective for induced pluripotent stem cells (iPSC) and human embryonic stem cells. Additionally, we describe methods for cryopreservation of intermediate cell banks that allow long-term storage. RPE generated using this protocol might be useful for iPSC disease-in-a-dish modeling or clinical application.

This protocol describes how to produce retinal pigment epithelial cells (RPE) from pluripotent stem cells. The method uses a combination of growth factors and small molecules to direct the differentiation of stem cells into immature RPE in fourteen days and mature, functional RPE after three months.

We describe a robust method to direct the differentiation of pluripotent stem cells into retinal pigment epithelial cells (RPE). The purpose of providing ...

Synaptic Microcircuit Modeling with 3D Cocultures of Astrocytes and Neurons from Human Pluripotent Stem Cells

A barrier to our understanding of how various cell types and signals contribute to synaptic circuit function is the lack of relevant models for studying the human brain. One emerging technology to address this issue is the use of three dimensional (3D) neural cell cultures, termed &#39;organoids&#39; or &#39;spheroids&#39;, for long term preservation of intercellular interactions including extracellular adhesion molecules. However, these culture systems are time consuming and not systematically generated. Here, we detail a method to rapidly and consistently produce 3D cocultures of neurons and astrocytes from human pluripotent stem cells. First, pre-differentiated astrocytes and neuronal progenitors are dissociated and counted. Next, cells are combined in sphere-forming dishes with a Rho-Kinase inhibitor and at specific ratios to produce spheres of reproducible size. After several weeks of culture as floating spheres, cocultures (&#39;asteroids&#39;) are finally sectioned for immunostaining or plated upon multielectrode arrays to measure synaptic density and strength. In general, it is expected that this protocol will yield 3D neural spheres that display mature cell-type restricted markers, form functional synapses, and exhibit spontaneous synaptic network burst activity. Together, this system permits drug screening and investigations into mechanisms of disease in a more suitable model compared to monolayer cultures.

In this protocol, we aim to describe a reproducible method for combining dissociated human pluripotent stem cell derived neurons and astrocytes together into 3D sphere cocultures, maintaining these spheres in free floating conditions, and subsequently measuring synaptic circuit activity of the spheres with immunoanalysis and multielectrode array recordings.

A barrier to our understanding of how various cell types and signals contribute to synaptic circuit function is the lack of relevant models for studying ...

Generation of 3D Skin Organoid from Cord Blood-derived Induced Pluripotent Stem Cells

The skin is the body&#8217;s largest organ and has many functions. The skin acts as a physical barrier and protector of the body and regulates bodily functions. Biomimetics is the imitation of the models, systems, and elements of nature for the purpose of solving complex human problems1. Skin biomimetics is a useful tool for in vitro disease research and in vivo regenerative medicine. Human induced pluripotent stem cells (iPSCs) have the characteristic of unlimited proliferation and the ability of differentiation to three germ layers. Human iPSCs are generated from various primary cells, such as blood cells, keratinocytes, fibroblasts, and more. Among them, cord blood mononuclear cells (CBMCs) have emerged as an alternative cell source from the perspective of allogeneic regenerative medicine. CBMCs are useful in regenerative medicine because human leukocyte antigen (HLA) typing is essential to the cell banking system. We provide a method for the differentiation of CBMC-iPSCs into keratinocytes and fibroblasts and for generation of a 3D skin organoid. CBMC-iPSC-derived keratinocytes and fibroblasts have characteristics similar to a primary cell line. The 3D skin organoids are generated by overlaying an epidermal layer onto a dermal layer. By transplanting this 3D skin organoid, a humanized mice model is generated. This study shows that a 3D human iPSC-derived skin organoid may be a novel, alternative tool for dermatologic research in vitro and in vivo.

We propose a protocol that shows how to differentiate induced pluripotent stem cell-derived keratinocytes and fibroblasts and generate a 3D skin organoid, using these keratinocytes and fibroblasts. This protocol contains an additional step of generating a humanized mice model. The technique presented here will improve dermatologic research.

The skin is the body&#8217;s largest organ and has many functions. The skin acts as a physical barrier and protector of the body and regulates bodily ...

In Vitro Generation of Somite Derivatives from Human Induced Pluripotent Stem Cells

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give rise to multiple cell types, including the myotome (MYO), sclerotome (SCL), dermatome (D), and syndetome (SYN), which in turn develop into skeletal muscle, axial skeleton, dorsal dermis, and axial tendon/ligament, respectively. Therefore, the generation of SMs and their derivatives from human induced pluripotent stem cells (iPSCs) is critical to obtain pluripotent stem cells (PSCs) for application in regenerative medicine and for disease research in the field of orthopedic surgery. Although the induction protocols for MYO and SCL from PSCs have been previously reported by several researchers, no study has yet demonstrated the induction of SYN and D from iPSCs. Therefore, efficient induction of fully competent SMs remains a major challenge. Here, we recapitulate human SM patterning with human iPSCs in vitro by mimicking the signaling environment during chick/mouse SM development, and report on methods of systematic induction of SM derivatives (MYO, SCL, D, and SYN) from human iPSCs under chemically defined conditions through the presomitic mesoderm (PSM) and SM states. Knowledge regarding chick/mouse&#160;SM development was successfully applied to the induction of SMs with human iPSCs. This method could be a novel tool for studying human somitogenesis and patterning without the use of embryos and for cell-based therapy and disease modeling.

We present here a protocol for the differentiation of human induced pluripotent stem cells into each somite derivative (myotome, sclerotome, dermatome, and syndetome) in chemically defined conditions, which has applications in future disease modeling and cell-based therapies in orthopedic surgery.

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give ...