The authors acknowledge U19 AI157984, U01 DK103168, U19 AI144297, P30 DK56338, P01 AI057788, U19 AI116497 grants and NASA Cooperative Agreement Notice/TRISH NNX16AO69A.

The organoid lines used here were obtained from the Texas Medical Center Digestive Disease Center GEMS Core. Briefly, to initially establish organoid lines, donor tissue samples were washed and enzymatically digested to release the intestinal crypts. Crypts were embedded in a basement membrane and cultured in a medium. The Institutional Review Board at Baylor College of Medicine approved the study protocol to obtain tissue samples from which organoid lines were established, and informed consent was obtained from all donors to establish organoid lines from the donated tissue.
1. Passaging of 3D HIOs to expand for differentiation
<ol>
	<li>Remove and discard medium from wells of organoids grown in 24-well plates (around the solid basement membrane) with a P1000 pipet. Add 300 &#181;L of 0.05% Trypsin-EDTA to the well and mechanically break up organoids by pipetting with a P1000 pipet up and down 5x.</li>
	<li>Incubate plate at 37 &#176;C for 4 min. Add 500 &#181;L of complete media without growth factors (CMGF- medium) with 10% FBS to each well (Table 1). Use a P1000 pipet and pipet CMGF medium and HIO mixture, 10x back and forth in the well. Transfer the entire volume into a 15 mL tube. Combine passage from multiple wells into the same 15 mL tube. Do not combine more than 10 wells per tube.</li>
	<li>Spin down cells at 4 &#176;C using a swing rotor centrifuge at 100 x g for 5 min. Remove all the medium, keeping the pellet at the bottom of the tube. Keep the tube on ice.</li>
	<li>Calculate the amount of basement membrane needed for the number of HIO plated, and&#160;resuspend the HIO pellet in 30 &#181;L/well of basement membrane using cold P200 pipet tips. Pipette the HIO basement membrane mixture as a droplet into the center of a 24-well plate using cold P200 pipet tips.</li>
	<li>Transfer the plate to a 37&#160;&#176;C incubator. Let the basement membrane solidify for 5-10 min, then add 500 &#181;L of room temperature complete medium containing WNT, R-spondin, noggin, EGF, and ROCK inhibitor (WRNE+Y; Table 1) to each well and culture in a 37&#160;&#176;C incubator. Refresh culture with WRNE+Y every other day for 7 days. 
	NOTE: A healthy HIO will be cystic in shape with a shiny budding epithelium (Figure 2). Cells in the middle of the cyst cannot be visualized. An unhealthy HIO will look dull and have a thick epithelium with a solid middle. The most important characteristic is the shiny appearance.</li>
</ol>
2. HIO differentiation: 3D format
<ol>
	<li>Use one well of 3D HIOs for 3 wells of 3D differentiated HIOs 1 week after culturing.</li>
	<li>Remove media from wells. Disperse basement membrane and HIOs using a P1000 pipet and add cold 500 &#181;L of CMGF- per well and pipet up and down at least 5x. Spin down HIOs at 4 &#176;C using a swing rotor centrifuge at 100 x g for 5 min. Remove all the medium keeping the pellet at the bottom of the tube.</li>
	<li>Add 30 &#181;L of basement membrane per well of HIOs being plated. Pipette the 30 &#181;L droplet of basement membrane with HIOs into a well of a 24-well plate. Incubate at 37 &#176;C for 10 min. Add 500 &#181;L of WRNE+Y/Diff (50/50) media.</li>
	<li>Switch the medium to differentiation medium after 24 h for 3 additional days, refreshing the medium every other day. Prepare 3 wells per sample to pool to reduce technical variability.</li>
</ol>
3. HIO differentiation: Monolayer format
<ol>
	<li>Coat the&#160;membrane cell culture inserts or wells of a 96-well plate with 100 &#181;L/well of human placental collagen IV (1mg/ml in 100mM acetic acid) diluted in cold H2O (1:30). Incubate at 37 &#176;C for a minimum of 1.5 h or maximum overnight. For membrane cell culture insert, add sterile H2O in the plate space to humidify the plate; for 96-well plate, add sterile H2O in the unused wells.</li>
	<li>Collect 3D HIOs cultured in WRNE for 7 days by removing the media and recovering the basement membrane and cells by adding 500 &#181;L/well of cold 0.5 mM EDTA (0.5 M EDTA diluted 1:1000 in sterile PBS). Use a P1000 pipet to pipet organoids and solution up and down 5x and transfer to a 15 mL microcentrifuge tube. Do not pool more than 10 wells of organoids per tube. Centrifuge for 5 min at 300 x g in a swinging bucket rotor at 4&#160;&#176;C. 
	NOTE: To prepare 3 wells on a 96-well plate, use 1 well of 3D HIOs. To prepare 1 membrane cell culture insert, use 1 well of 3D HIOs (seeding density of single cells is approximately 1-2 x 105 cells/well for 96-well plate, 2.5-3 x 105 cells/well for membrane cell culture insert).</li>
	<li>Remove 500 &#181;L of media, leaving the pellet at the bottom of the tube. Dissociate the HIOs by adding 500 &#181;L of 0.05% Trypsin/0.5 mM EDTA and incubating for 4-5 min at 37&#160;&#176;C. Vigorously pipette up and down for ~50x using a P1000. Avoid making bubbles by pipetting against the side of the tube.</li>
	<li>Inactivate the trypsin by adding 1 mL of CMGF- containing 10% FBS. Filter out large clumps of undigested cells by wetting a 40 &#181;m cell strainer with 1 mL of CMGF- containing 10% FBS and adding the cells to the top of the cell strainer. Use gravity to allow the cells to pass through the strainer and discard the cell strainer containing cell clumps.</li>
	<li>Collect the cells by centrifugation for 5 min at 400 x g in a swinging bucket rotor at room temperature.</li>
	<li>Remove the liquid from the collagen-coated membrane cell culture insert or from the 96-well plate. Resuspend the HIO pellet in 100 &#181;L/well of WRNE containing 10 &#181;M Y-27632, then pipette into the upper compartment of the membrane cell culture insert or into the 96-well plate. For membrane cell culture insert, add 600 &#181;L of WRNE containing 10 &#181;M Y-27632 into the lower compartment of the well.</li>
	<li>Remove the medium after 24 h from both the upper and lower part of the membrane cell culture insert or from the 96-well plate&#160;and replace with differentiation medium for 5 days. Prepare 3 wells per sample to pool to reduce technical variability.</li>
</ol>
4. Preparation of single cell suspensions from differentiated 3D HIOs for single cell transcriptomics
<ol>
	<li>Place enzymatic cell digestion reagent at 37 &#176;C in a CO2 incubator&#160;to thaw and warm 30 min prior to initiation of 3D HIO digestion. Check the HIOs using a bright field microscope at 10x to ensure cell health.</li>
	<li>Remove the media from the wells and add 500 &#181;L of cold cell recovery solution to the wells. Pipette up and down a few times to liberate the cells from the basement membrane using a P1000 pipette and standard pipette tips. Transfer the cell suspension to a 1.5 mL microcentrifuge tube. 
	NOTE: The use of replicate wells ensures adequate cell numbers and reduces well-to-well variation. Do not combine wells before step 4.7 below.</li>
	<li>Incubate the tubes of cells on ice for 10 min, pipetting up and down every 5 min. Collect the cells by centrifugation for 3 min at 400 x g at 4 &#176;C.</li>
	<li>Remove the liquid from the tube, taking care not to disturb the cell pellet. Resuspend the cells in 500 &#181;L of pre-warmed enzymatic cell digestion reagent. Pipette up and down with a P1000 at least 10x.</li>
	<li>Incubate the HIOs for 30 min at 37 &#176;C in a CO2 incubator. Every 10 min, pipette the entire volume 10x using a P1000 pipette to help dissociate the cells. Avoid introducing air bubbles into the cell suspension.</li>
	<li>Pellet the cells for 3 min at 400 x g at 4 &#176;C. Remove the supernatant, resuspend the cells in 1 mL of differentiation media, and store on ice. 
	NOTE: From this point on, the HIOs must always be kept on ice.</li>
	<li>Pipette the cells up and down 50x rapidly using a P1000 to ensure HIOs are dissociated into single cells. Take care not to introduce air bubbles at this step, as it will cause cell loss.</li>
	<li>Filter the entire volume through a 70 &#181;m tip strainer using a P1000 pipette tip. Use a 1.5 mL microcentrifuge tube to collect the eluate. 
	NOTE: The filter tip will not become clogged if digestion time is sufficient. Use multiple filter tips if the filter becomes clogged; do not force the volume through the filter.</li>
	<li>Repeat step 4.8 with a 40 &#181;m tip strainer. Store samples on ice.</li>
	<li>Count viable single cells on a cell counting chamber using trypan blue exclusion by adding 5 &#181;L of 0.4% trypan blue to 5 &#181;L of cell suspension. Dilute the sample as needed to 1000 cells/&#181;L. If the cell density is less than 1000 cells/&#181;L, pellet cells for 2 min at 400 x g at 4 &#176;C, remove the original media, and resuspend in cell culture media. This protocol typically yields 5 x 105-1 x 106 cells. 
	NOTE: Preparation of a high-quality suspension (90% viable and 90% single cells) is essential for high quality single-cell data. However, experience indicates viability as low as 75% can be accepted in cases where treatment, such as infection or small molecule application, impact viability.</li>
	<li>Prepare DNA libraries for single cell transcriptional profiling platforms according to the manufacturer&#39;s protocols. Process the data according to best practice protocols for scRNAseq data analysis13,14.</li>
</ol>
5. Preparation of single cell suspensions from HIOs differentiated on membrane cell culture insert
<ol>
	<li>Place enzymatic cell digestion reagent at 37 &#176;C in a CO2 incubator to thaw and warm 30 min prior to initiation of HIO membrane cell culture insert digestion. Divide the pre-warmed enzymatic cell digestion reagent into 200 &#181;L aliquots in 1.5 mL microcentrifuge tubes, 1 tube per membrane cell culture insert. Keep the tubes in the 37 &#176;C incubator until ready for use.</li>
	<li>Prepare PBS-EDTA by adding 5 &#181;L of 0.5 M EDTA to 5 mL of PBS. Aliquot 500 &#181;L of PBS-EDTA into a 24-well plate, 1 well per membrane cell culture insert.</li>
	<li>Wash the cells with PBS-EDTA: transfer the membrane cell culture inserts from wells containing growth media to the wells containing PBS-EDTA. Remove the cell culture media from the apical side and replace it with 100 &#181;L of PBS-EDTA. Take care not to disturb the cell layer.</li>
	<li>Immediately discard the PBS-EDTA added to the apical side of the membrane cell culture inserts. Remove the membrane cell culture insert from the well, blot it by gently touching the edge to a paper towel, and then invert it on the benchtop. Use a sharp scalpel blade to remove the membrane from the insert by cutting around the inner circumference of the membrane. Work quickly to prevent drying.</li>
	<li>Use forceps to transfer the membrane to the pre-warmed 1.5 mL microcentrifuge tube filled with enzymatic cell digestion reagent and ensure the membrane is completely submerged. Repeat for all additional membrane cell culture inserts. 
	NOTE: Increasing the volume of the enzymatic cell digestion reagent to 500 &#181;L may aid in dissociating dense monolayers.</li>
	<li>Dissociate the cells by incubating tubes with membranes at 37 &#176;C in a CO2 incubator. Mix by gently pipetting the entire volume 5x with a 200 &#181;L pipette every 10 min for a total of 30 min. Avoid bubbles and suction of the membrane to preserve viability.</li>
	<li>Transfer a small aliquot of cells (1-2 &#181;L) to a glass slide every 10 min to assess dissociation by qualitatively assessing the percent of single cells. It may take up to 50 min with additional pipetting to achieve 80%-90% single cells, depending on the HIO type. Gently scrape the membrane with a pipette tip during mixing steps to encourage dissociation, particularly for hard to dissociate cells, however scraping may impact viability.</li>
	<li>Combine 3 replicate wells per condition in a single 1.5 mL microcentrifuge tube (600 &#181;L total). Add 400 &#181;L of cell culture media (diff) + 10 &#181;M ROCKi (1 mL total volume). Mix gently by pipetting. 
	NOTE: The use of replicate wells ensures adequate cell numbers and reduces well-to-well variation. Wells should be pooled at this step.</li>
	<li>Filter the entire volume through a 70 &#181;m tip strainer using a 1 mL pipette tip. Collect the flow through in a fresh 1.5 mL microcentrifuge tube. 
	NOTE: The filter tip will not become clogged if digestion time is sufficient. Use multiple filter tips if the filter becomes clogged; do not force the volume through.</li>
	<li>Repeat step 5.9 with a 40 &#181;m tip strainer. Store samples on ice.</li>
	<li>Count viable single cells on a cell counting chamber using trypan blue exclusion by adding 5 &#181;L of 0.4% trypan blue to 5 &#181;L of cell suspension. Dilute sample as needed to 1000 cells/ &#181;L. If the cell density is less than 1000 cells/ &#181;L, spin 2 min at 400 x g at 4 &#176;C to pellet the cells, remove the original media, and resuspend in WRNE+Y at the desired cell density. This protocol typically yields 4 x 105 - 6 x 105 cells. 
	NOTE: Preparation of high-quality suspension (90% viable and 90% single cells) is essential for high quality single-cell data. However, experience indicates viability as low as 75% can be accepted in cases where treatment, such as infection or small molecule application, impact viability.</li>
	<li>Prepare DNA libraries for the single cell transcriptional profiling platforms according to the manufacturer&#39;s protocols. Process the data according to best practice protocols for scRNAseq data analysis13,14.</li>
</ol>
6. Preparation of single cell suspensions from HIOs differentiated as 96-well monolayers
<ol>
	<li>Place enzymatic cell digestion reagent at 37 &#176;C in a CO2 incubator to thaw and warm 30 min prior to initiation of monolayer HIO digestion.</li>
	<li>Prepare PBS-EDTA by adding 5 &#181;L of 0.5 M EDTA to 5 mL of PBS. Discard the cell culture media from the 96-well plate and replace it with 100 &#181;L of PBS-EDTA. Take care not to disturb the cell layer.</li>
	<li>Dissociate the cells: Discard the PBS-EDTA and add 100 &#181;L of warm enzymatic cell digestion reagent to each well. Place the plate in the 37 &#176;C in a 5% CO2 incubator and mix by gently pipetting the entire volume 5x with a 200 &#181;L pipette tip every 10 min for 20-30 min. Avoid bubbles to preserve viability. 
	NOTE: Increasing the volume of enzymatic cell digestion reagent to 500 &#181;L may aid in dissociating dense monolayers.</li>
	<li>Transfer a small aliquot of cells (1-2 &#181;L) to a glass slide every 10 min to assess dissociation. It may take up to 50 min to achieve 80%-90% single cells, depending on the HIO type. Gently scrape the plate with a pipette tip during mixing steps to encourage dissociation, particularly for hard to dissociate cells; however, scraping may impact viability.</li>
	<li>Combine 3 replicate wells per condition in a single 1.5 mL microcentrifuge tube (300 &#181;L total). Add 700 &#181;L of cell culture media (diff) + 10 uM ROCKi (1 mL total volume). Mix gently by pipetting. 
	NOTE: The use of replicate grown wells ensures adequate cell numbers and reduces well-to-well variation.</li>
	<li>Filter the entire volume through a 70 &#181;m tip strainer using a 1 mL pipette tip. Collect the flow through in a fresh 1.5 mL microcentrifuge tube. 
	NOTE: The filter tip will not become clogged if enzymatic cell digestion reagent digestion time is sufficient. Use multiple filter tips if the filter becomes clogged; do not force the volume through.</li>
	<li>Repeat step 6.6 with a 40 &#181;m tip strainer. Store samples on ice.</li>
	<li>Count viable single cells on a cell counting chamber using trypan blue exclusion by adding 5 &#181;L of 0.4% trypan blue to 5 &#181;L of cell suspension. Dilute as needed to 1000 cells/&#181;L. If the cell density is less than 1000 cells/&#181;L, spin 2 min at 400 x g 4 &#176;C to pellet the cells, remove the original media, and resuspend in cell culture media + ROCKi at the desired cell density. This protocol typically yields 2 x 105 - 6 x 105 cells. 
	NOTE: Preparation of high-quality suspension (90% viable and 90% single cells) is essential for high quality single-cell data. However, experience indicates viability as low as 75% can be accepted in cases where treatment, such as infection or small molecule application, impact viability.</li>
	<li>Prepare DNA libraries according to the single cell transcriptional profiling platform manufacturer&#39;s protocols. Process the data according to best practice protocols for scRNAseq data analysis13,14.</li>
</ol>

Integrating Single-Cell Transcriptomics with Human Intestinal Organoids

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L., 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=Development+of+an+enhanced+human+gastrointestinal+epithelial+culture+system+to+facilitate+patient-based+assays.">Development of an enhanced human gastrointestinal epithelial culture system to facilitate patient-based assays.</a> Gut. 64 (6), 911-920 (2015).</li><li>Elmentaite, R., 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=Cells+of+the+human+intestinal+tract+mapped+across+space+and+time.">Cells of the human intestinal tract mapped across space and time.</a> Nature. 597 (7875), 250-255 (2021).</li><li>Hickey, J. W., 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=Organization+of+the+human+intestine+at+single-cell+resolution.">Organization of the human intestine at single-cell resolution.</a> Nature. 619 (7970), 572-584 (2023).</li><li>Burclaff, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+proximal-to-distal+survey+of+healthy+adult+human+small+intestine+and+colon+epithelium+by+single-cell+transcriptomics.">A proximal-to-distal survey of healthy adult human small intestine and colon epithelium by single-cell transcriptomics.</a> Cell Mol Gastroenterol Hepatol. 13 (5), 1554-1589 (2022).</li><li>Triana, S., 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=Single-cell+transcriptomics+reveals+immune+response+of+intestinal+cell+types+to+viral+infection.">Single-cell transcriptomics reveals immune response of intestinal cell types to viral infection.</a> Mol Syst Biol. 17 (7), e9833 (2021).</li><li>Triana, S., 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=Single-cell+analyses+reveal+SARS-CoV-2+interference+with+intrinsic+immune+response+in+the+human+gut.">Single-cell analyses reveal SARS-CoV-2 interference with intrinsic immune response in the human gut.</a> Mol Syst Biol. 17 (4), e10232 (2021).</li><li>Fujii, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+intestinal+organoids+maintain+self-renewal+capacity+and+cellular+diversity+in+niche-inspired+culture+condition.">Human intestinal organoids maintain self-renewal capacity and cellular diversity in niche-inspired culture condition.</a> Cell Stem Cell. 23 (6), 787-793 (2021).</li><li>Beumer, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=BMP+gradient+along+the+intestinal+villus+axis+controls+zonated+enterocyte+and+goblet+cell+states.">BMP gradient along the intestinal villus axis controls zonated enterocyte and goblet cell states.</a> Cell Rep. 38 (9), 110438 (2022).</li><li>Beumer, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution+mRNA+and+secretome+atlas+of+human+enteroendocrine+cells.">High-resolution mRNA and secretome atlas of human enteroendocrine cells.</a> Cell. 182 (4), 1062-1064 (2020).</li><li>Busslinger, G. 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The authors have no conflicts of interest.

Using single cell genomics platforms, complex biological systems, such as tissue derived HIO cultures that model the intestinal epithelium, can be broken down to yield individual cellular contributions to overall biological response4,5,6. Cellular heterogeneity and rare cell populations can also be identified and interrogated. Cellular input needs to be optimized to maximize output using single cell transcriptomic-based platforms. Here we describe protocols that will yield highly viable and good quality single cell suspensions that will increase the likelihood of obtaining downstream high quality transcriptomic data. Familiarity with the protocol is of utmost importance, and it is recommended that several practice runs be performed before proceeding with library preparation. Reproducible achievement of viable single cell suspensions is suggested prior to using the cells for library preparation. The rapidness at which the protocol is implemented is of utmost importance as speed is directly proportional to viability outcomes. Based on this, limiting the number of samples handled at one time is advised. Interfacing with the entity that will prepare the libraries prior to initiating these protocols for assistance with troubleshooting is recommended.
HIO viability directly influences the DNA library sent for sequencing. Cell viability of the HIO depends on several steps in the preparation of the single cell suspension, including dissociation, centrifugation, buffers, pipetting, and counting accuracy. The goal of preparing the HIOs for the platform is to balance the maintenance of cell viability with sample quality. Critical to obtaining high quality data is the minimization of cellular aggregates, dead cells, non-cellular nucleic acids, and biochemical inhibitors of reverse transcription. Dying cells increase nucleic acid noise and contribute to cell clumping, leading to data and platform failures7,8,9,10,11,12. Filtering with an appropriate filter size can help remove large aggregates and improve data quality.
Several factors need to be considered to minimize HIO cell death when preparing single cell suspensions. Obtaining at least 80% viable cells is necessary, and &#62;90% viability is even more desirable. Samples with high numbers of non-viable cells can be improved using strategies to remove dead cells, such as column-based microbeads, although these require more initial cells and larger sample volumes due to loss during handling. HIOs are particularly sensitive to buffers and will undergo cell death if left too long at RT in certain buffers. Organoid media results in the least amount of cell loss and aggregate formation. Pipetting can also affect HIO viability during dissociation. Regular bore tips can shear organoids, helping to dissociate into single cell suspensions; however, pipetting too rapidly with a regular bore tip can cause HIO cell damage from the shearing forces. Slow pipetting with wide bore tips minimizes stress on the HIO cells and greatly improves viable cell numbers downstream. Centrifugation, washing, and resuspending are other factors that can influence the quality of HIO single cells suspensions. Swinging bucket centrifugation results in gentler pelleting of HIO cells, resulting in lower numbers of dead cells while minimizing cell loss. Finally, counting accuracy to determine concentration is essential to ensure the maximum number of cells reach the platform for library synthesis. Attention to these details will result in the minimization of stress on the HIO cells during the isolation process and ensure the highest probability of data return after processing.
Although single cell transcriptomics is a powerful tool to dissect biological profiles and responses at the single cell level4,5,6, there are several limitations that need to be considered when applying the technology to analyze human intestinal organoid cultures. First, there can be significant transcriptional variation because of technical variability introduced during library preparation and sequencing or due to batch effects resulting from sample preparation. In addition, sequencing can result in coverage bias where there is uneven sequencing depth across genes or cells. This causes challenges when detecting lowly expressed genes or identifying rare cell populations. Second, the identification of cell types can be difficult due to the cellular and transcriptional heterogeneity of the organoid cultures and a less differentiated cellular profile when compared to the native intestinal epithelium. Coupling transcriptional responses to functional phenotypes is also a challenge and requires additional validation using other approaches or assays. Third, this approach does not include consideration of spatial context or temporal dynamics of the cells. The dissociation procedure removes the ability to infer cell-cell interactions from the transcriptional data. It only provides a single snapshot in time of the cellular state rather than a biologic continuum. Finally, single cell transcriptional approaches can be costly and require specialized computational tools and bioinformatics expertise. However, this approach still remains a dominant state-of-the-art tool for understanding cellular heterogeneity and identifying novel cell types.

The small intestinal epithelium has two distinct zones: the crypt that houses the intestinal stem cell (ISC) and the villus, which is comprised of differentiated cells of the secretory and absorptive lineages. Adding to this complexity is the regional specificity of the epithelium that provides unique functional properties between the regions of the small intestine. Pioneering work established culture conditions in which both the human small intestinal crypt and villus zones can be generated ex vivo from surgical tissues or tissue biopsies1. These cultures are bridging the gap between animal studies and clinical trials and are revealing previously unrecognized cell biology, biochemistry, and physiology of the gastrointestinal tract. The HIOs are propagated as 3D spherical structures using a media with growth factors that promote stem cell viability and extracellular support matrices. These conditions result in a crypt-like HIO model that consists mostly of progenitors and stem cells. Removal of the growth factors promotes ISC differentiation (villus-like model) and production of mature intestinal epithelial cells (goblet, enteroendocrine, tuft, enterocyte) in appropriate ratios along with cell proliferation and differentiation, polarization, barrier integrity, regional specific features, and appropriate physiological responses2. HIO cultures are genetically stable and can be propagated indefinitely in their crypt-like state. Easy access to the apical surface of these cultures is provided by culture conditions that allow growth in a monolayer format3. HIOs also allow considerations of host individual variability such as genetics, age, sex, ethnicity, and disease status to be included in biological analyses. Analytic and functional assessment tools are identical to those used in approaches centered on transformed cell lines and include a variety of molecular techniques such as flow cytometry, microscopy, transcriptomics, proteomics, and metabolomics.
Single cell transcriptomics is revolutionizing our understanding of the biology and physiology of the small intestine by providing insight into the individual contributions of each cell type to a biological process. Pioneering work using this technology has provided a landscape of the cell types present in the native human intestine4,5,6. Single cell transcriptional profiling platforms allow exploration of the transcriptional landscape of individual cells, allowing cell heterogeneity to come to the forefront of scientific exploration. In some single cell transcriptional profiling platforms, microfluidic partitioning and barcoding are used to generate cDNA libraries from cellular polyadenylated mRNAs obtained from up to 10,000 cells per sample. On this platform, droplets containing single cells, barcoded oligonucleotides, reverse transcription reagents, and oil form a reaction vesicle that results in all cDNAs from a single cell having the same barcode. The barcoded cDNAs can then be efficiently sequenced using next generation sequencing. Data generated can be handled through software and visualization tools, which convert the barcoded sequences into visualization maps and single cell transcriptional profiles. Cell populations can be identified using publicly available databases of human small intestinal epithelium4,5,6. Although many studies have utilized this platform to interrogate murine intestinal organoids at the single cell level, the analysis of single cell transcriptional responses of HIOs has lagged behind7,8,9,10,11,12.
Here, we provide a step-by-step guide to isolating viable cells from small intestinal HIOs for processing on single cell transcriptional profiling platforms (Figure 1). We provide culturing and differentiation guidelines along with media components that have been optimized for epithelial differentiation. We outline cell recovery methods for three different culture formats: three dimensional (3D) and monolayer cultures either on plastic or on membrane cell culture inserts. We provide sample clustering data obtained using open-source software to derive differentially expressed genes in each cluster.

<table><tbody><tr><td>[Leu15]-Gastrin I</td><td>Sigma-Aldrich</td><td>G9145</td><td>10 nM</td></tr><tr><td>0.05% Trypsin-EDTA</td><td>Invitrogen</td><td>25300054</td><td></td></tr><tr><td>0.4% Trypan blue</td><td>Millipore-Sigma</td><td>T8154</td><td></td></tr><tr><td>0.5 M EDTA</td><td>Corning</td><td>46-034-CI</td><td></td></tr><tr><td>1x PBS Ca- Mg-</td><td>Corning</td><td>21-040-CM</td><td></td></tr><tr><td>24 mm Transwell</td><td>Costar</td><td>3412</td><td></td></tr><tr><td>24 well Nunclon delta surface tissue culture dish</td><td>Thermo Scientific</td><td>142475</td><td></td></tr><tr><td>40 &amp;micro;m cell strainer</td><td>Falcon</td><td>352340</td><td></td></tr><tr><td>40 &amp;micro;m Flowmi tip strainer</td><td>SP Bel-Art Labware</td><td>H13680-0040</td><td></td></tr><tr><td>70 &amp;micro;m Flowmi tip strainer</td><td>SP Bel-Art Labware</td><td>H13680-0070</td><td></td></tr><tr><td>96 well plate</td><td>Corning</td><td>3595</td><td></td></tr><tr><td>A-83-01</td><td>Tocris</td><td>2939</td><td>500 nM</td></tr><tr><td>Accutase</td><td>StemCell Technologies</td><td>7920</td><td></td></tr><tr><td>Advanced DMEM/F12</td><td>Invitrogen</td><td>12634-028</td><td></td></tr><tr><td>B27 supplement</td><td>Invitrogen</td><td>17504-044</td><td>1X</td></tr><tr><td>Chromium Next GEM Single Cell 3&amp;rsquo; GEM, Library &amp;amp; Gel Bead Kit v3.1</td><td>10x Genomics</td><td>PN-1000128</td><td></td></tr><tr><td>Collagen IV</td><td>Sigma-Aldrich</td><td>C5533-5MG</td><td>33 &amp;micro;g/mL</td></tr><tr><td>Corning Cell Recovery Solution&amp;nbsp;</td><td>VWR</td><td>354253</td><td></td></tr><tr><td>DPBS (Mg2-, Ca2-)</td><td>Invitrogen</td><td>14190-136</td><td>1X</td></tr><tr><td>GlutaMAX-I</td><td>Invitrogen</td><td>35050-061</td><td>2 mM</td></tr><tr><td>HEPES 1M</td><td>Invitrogen</td><td>15630-080</td><td>10 mM</td></tr><tr><td>L-WRN conditioned media</td><td>ATCC</td><td>CRL-3276</td><td></td></tr><tr><td>Matrigel, GFR, phenol free</td><td>Corning</td><td>356231</td><td></td></tr><tr><td>mouse recombinant EGF</td><td>Invitrogen</td><td>PMG8043</td><td>50 ng/mL</td></tr><tr><td>N2 supplement</td><td>Invitrogen</td><td>17502-048</td><td>1X</td></tr><tr><td>N-Acetylcysteine</td><td>Sigma-Aldrich</td><td>A9165-5G</td><td>500 &amp;micro;M</td></tr><tr><td>Nicotinamide</td><td>Sigma-Aldrich</td><td>N0636</td><td>10 mM</td></tr><tr><td>SB202190</td><td>Sigma-Aldrich</td><td>S7067</td><td>10 &amp;micro;M</td></tr><tr><td>Transwell</td><td>Corning</td><td>3413</td><td></td></tr><tr><td>Y27632</td><td>Stem Cell Technologies</td><td>72308</td><td>10 &amp;micro;M</td></tr></tbody></table>

using human intestinal organoids to understand the small intestine epithelium at the single cell transcriptional level

Single cell transcriptomics has revolutionized our understanding of the cell biology of the human body. State-of-the-art human small intestinal organoid cultures provide ex vivo model systems that bridge the gap between animal models and clinical studies. The application of single cell transcriptomics to human intestinal organoid (HIO) models is revealing previously unrecognized cell biology, biochemistry, and physiology of the GI tract. The advanced single cell transcriptomics platforms use microfluidic partitioning and barcoding to generate cDNA libraries. These barcoded cDNAs can be easily sequenced by next generation sequencing platforms and used by various visualization tools to generate maps. Here, we describe methods to culture and differentiate human small intestinal HIOs in different formats and procedures for isolating viable cells from these formats that are suitable for use in single-cell transcriptional profiling platforms. These protocols and procedures facilitate the use of small intestinal HIOs to obtain an increased understanding of the cellular response of human intestinal epithelium at the transcriptional level in the context of a variety of different environments.

Single-cell suspensions were pooled from 2-3 wells of membrane cell culture insert, monolayer, and 3D HIOs to ensure sufficient cell yield and reduce well-to-well variation. Single cell libraries were prepared using reagents specific to the single cell transcriptional profiling platform. and sequenced with paired end reads on a next generation sequencing platform, 30,000 reads/cell. Reads were mapped, counted, and analyzed using analytical tools for single cell genomics. Low-quality cells with more than 20% mitochondrial read, or less than 200 counted genes were excluded from the analysis. To assess the quality of the cells, we plotted the number of genes, UMIs, and percent mitochondrial reads per cell (Figure 3); high-quality cells contain approximately 3500 genes, 15,000 UMIs, and 10% mitochondrial reads. Following filtering, we obtained 4000 to 9500 single cells depending on the HIO growth format. Unsupervised clustering and UMAP dimension reduction identified distinct clusters representing expected cell types, including absorptive enterocytes and secretory cells (Figure 4).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/66749/66749fig01.jpg" /> 
Figure 1: Outline of protocol steps. Schematics outlining the major steps in plating HIOs in different formats to single cell data workflow. This image was created using Biorender. <a href="https://www.jove.com/files/ftp_upload/66749/66749fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/66749/66749fig02.jpg" /> 
Figure 2: Bright field images. HIOs ready for processing were imaged using a bright field microscope at 5X magnification. Left, 3D organoids; middle, 96-well plate; right, transwell. Scale bars = 200 &#181;m. <a href="https://www.jove.com/files/ftp_upload/66749/66749fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/66749/66749fig03.jpg" /> 
Figure 3: Quality control of data. Example metrics of analyzed single cells isolated from jejunal HIOs grown as monolayers on 96-well plates. Violin plots show the number of genes (nFeature_RNA), UMIs (nCount_RNA), and percent mitochondrial reads (percent.mt) per cell. <a href="https://www.jove.com/files/ftp_upload/66749/66749fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/66749/66749fig04.jpg" /> 
Figure 4: UMAPs of analyzed single cells. (A) A total of 9952 single cells were isolated from differentiated jejunal HIOs grown in 96-well plates. (B) A total of 5623 single cells were isolated from differentiated jejunal HIOs grown on membrane cell culture inserts. (C) A total of 4402 single cells were isolated from differentiated ileal 3D HIOs. <a href="https://www.jove.com/files/ftp_upload/66749/66749fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>WRNE Growth Medium</td>
			<td></td>
			<td></td>
			<td>Differentiation medium</td>
		</tr>
		<tr>
			<td>Component</td>
			<td>Volume</td>
			<td>Final Concentration</td>
			<td>WRNE medium without L-WRN conditioned medium, Nicotinamide and SB202190</td>
		</tr>
		<tr>
			<td>*Y-27632 (5 mM) optional&#160;</td>
			<td>200 &#181;L</td>
			<td>10 &#181;M</td>
			<td></td>
		</tr>
		<tr>
			<td>A 83-01 (500 &#181;M)</td>
			<td>100 &#181;L</td>
			<td>&#160;500&#160; nM</td>
			<td></td>
		</tr>
		<tr>
			<td>Advanced DMEM/F12</td>
			<td>45 mL</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>B27</td>
			<td>2 mL</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>EGF (50 &#181;g/mL)</td>
			<td>100 &#181;L</td>
			<td>50 ng/mL</td>
			<td></td>
		</tr>
		<tr>
			<td>Gastrin (10 &#181;M)</td>
			<td>100 &#181;L</td>
			<td>10 nM</td>
			<td></td>
		</tr>
		<tr>
			<td>GlutaMax (100X)</td>
			<td>1 mL</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES 1 M</td>
			<td>1 mL</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>L-WRN Con- Media</td>
			<td>50 mL</td>
			<td>~50%</td>
			<td></td>
		</tr>
		<tr>
			<td>N2</td>
			<td>1 mL</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>N-Acetylcysteine (500 mM)</td>
			<td>100 &#181;L</td>
			<td>&#160;500 &#181;M</td>
			<td></td>
		</tr>
		<tr>
			<td>Nicotinamide 1 M</td>
			<td>1 mL</td>
			<td>10 mM</td>
			<td></td>
		</tr>
		<tr>
			<td>SB202190 (10 mM)</td>
			<td>100 &#181;L</td>
			<td>&#160;10 &#181;M</td>
			<td></td>
		</tr>
		<tr>
			<td>Total Volume</td>
			<td>100 mL</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>CMGF- Medium</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;Advanced DMEM/F12&#160;</td>
			<td>500 mL</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;Glutamax&#160;</td>
			<td>5 mL</td>
			<td>100X</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;1 M Hepes</td>
			<td>5 mL</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>
Table 1: Composition of various media used.

Author Spotlight: Integrating Single-Cell Transcriptomics with Organoid Cultures for Advanced Research and Therapeutic Insights

The protocol combines human intestinal organoid technology with single cell transcriptomic analysis to provide significant insight into previously unexplored intestinal biology.

Using Human Intestinal Organoids to Understand the Small Intestine Epithelium at the Single Cell Transcriptional Level

Single cell transcriptomics has revolutionized our understanding of the cell biology of the human body. State-of-the-art human small intestinal organoid ...

using-human-intestinal-organoids-to-understand-small-intestine

Nanyang Technological University

Research

JoVE Journal

Biology

652 Views.  Baylor College of Medicine. The protocol combines human intestinal organoid technology with single cell transcriptomic analysis to provide significant insight into previously unexplored intestinal biology. 

Video: Author Spotlight: Integrating Single-Cell Transcriptomics with Organoid Cultures for Advanced Research and Therapeutic Insights

Real-time Measurement of Epithelial Barrier Permeability in Human Intestinal Organoids

Advances in 3D culture of intestinal tissues obtained through biopsy or generated from pluripotent stem cells via directed differentiation, have resulted in sophisticated in vitro models of the intestinal mucosa. Leveraging these emerging model systems will require adaptation of tools and techniques developed for 2D culture systems and animals. Here, we describe a technique for measuring epithelial barrier permeability in human intestinal organoids in real-time. This is accomplished by microinjection of fluorescently-labeled dextran and imaging on an inverted microscope fitted with epifluorescent filters. Real-time measurement of the barrier permeability in intestinal organoids facilitates the generation of high-resolution temporal data in human intestinal epithelial tissue, although this technique can also be applied to fixed timepoint imaging approaches. This protocol is readily adaptable for the measurement of epithelial barrier permeability following exposure to pharmacologic agents, bacterial products or toxins, or live microorganisms. With minor modifications, this protocol can also serve as a general primer on microinjection of intestinal organoids and users may choose to supplement this protocol with additional or alternative downstream applications following microinjection.

This protocol describes the measurement of epithelial barrier permeability in real-time following pharmacologic treatment in human intestinal organoids using fluorescent microscopy and live cell microscopy.

Advances in 3D culture of intestinal tissues obtained through biopsy or generated from pluripotent stem cells via directed differentiation, have resulted ...

Developmental Biology

Establishment of Human Epithelial Enteroids and Colonoids from Whole Tissue and Biopsy

The epithelium of the gastrointestinal tract is constantly renewed as it turns over. This process is triggered by the proliferation of intestinal stem cells (ISCs) and progeny that progressively migrate and differentiate toward the tip of the villi. These processes, essential for gastrointestinal homeostasis, have been extensively studied using multiple approaches. Ex vivo technologies, especially primary cell cultures have proven to be promising for understanding intestinal epithelial functions. A long-term primary culture system for mouse intestinal crypts has been established to generate 3-dimensional epithelial organoids. These epithelial structures contain crypt- and villus-like domains reminiscent of normal gut epithelium. Commonly, termed &#8220;enteroids&#8221; when derived from small intestine and &#8220;colonoids&#8221; when derived from colon, they are different from organoids that also contain mesenchyme tissue. Additionally, these enteroids/colonoids continuously produce all cell types found normally within the intestinal epithelium. This in vitro organ-like culture system is rapidly becoming the new gold standard for investigation of intestinal stem cell biology and epithelial cell physiology. This technology has been recently transferred to the study of human gut. The establishment of human derived epithelial enteroids and colonoids from small intestine and colon has been possible through the utilization of specific culture media that allow their growth and maintenance over time. Here, we describe a method to establish a small intestinal and colon crypt-derived system from human whole tissue or biopsies. We emphasize the culture modalities that are essential for the successful growth and maintenance of human enteroids and colonoids.

We describe a method to establish human enteroids from small intestinal crypts and colonoids from colon crypts collected from both surgical tissue and biopsies. In this methodological article, we present the culture modalities that are essential for the successful growth and maintenance of human enteroids and colonoids.

The epithelium of the gastrointestinal tract is constantly renewed as it turns over. This process is triggered by the proliferation of intestinal stem ...

Medicine

Innervation of Human Intestinal Organoids

The complexity of intestinal cytoarchitecture and function poses significant challenges for the creation of the bioengineered small intestine. Techniques for generating human intestinal organoids (HIOs) resembling human small intestine have been previously reported. HIOs contain epithelium and mesenchyme but lack other critical components of functional intestine such as the enteric nervous system (ENS), immune cells, vasculature, and microbiome. Two independent research groups have published distinct methods to innervate HIOs with an ENS. Here we discuss a unique method of incorporating the ENS into an HIO-derived bioengineered small intestine, which utilizes components of these prior reports to optimize progenitor cell identity as well as developmental timing.
Human pluripotent stem cells (hPSCs) are differentiated to independently generate HIOs and enteric neural crest cells (ENCCs) by temporal regulation of differentiation markers over a period of several days per published protocols. Once HIOs reach the mid-hindgut spheroid stage (approximately day 8), day 15-21 ENCC spheroids are dissociated, co-cultured with HIOs, and suspended within clear three-dimensional (3D) basement membrane matrix droplets. HIO + ENCC co-cultures are maintained in vitro for 28-40 days before transplantation into &#62;9-week-old immunodeficient mice for further development and maturation. Transplanted HIOs (tHIOs) with ENS can be harvested 4-20 weeks later. This method integrates elements from two previously published techniques by utilizing ENCCs generated from hPSCs and co-culturing them with HIOs at an early stage of development to maximize exposure to early developmental cues that likely contribute to the formation of a more mature intestinal morphology.

Human intestinal organoids must be innervated to better recapitulate the structure and function of the native human intestine. Here, we present one method for incorporating an enteric nervous system into these constructs.

The complexity of intestinal cytoarchitecture and function poses significant challenges for the creation of the bioengineered small intestine. Techniques ...

Using Human Induced Pluripotent Stem Cell-derived Intestinal Organoids to Study and Modify Epithelial Cell Protection Against Salmonella and Other Pathogens

The intestinal &#8216;organoid&#8217; (iHO) system, wherein 3-D structures representative of the epithelial lining of the human gut can be produced from human induced pluripotent stem cells (hiPSCs) and maintained in culture, provides an exciting opportunity to facilitate the modeling of the epithelial response to enteric infections. In vivo, intestinal epithelial cells (IECs) play a key role in regulating intestinal homeostasis and may directly inhibit pathogens, although the mechanisms by which this occurs are not fully elucidated. The cytokine interleukin-22 (IL-22) has been shown to play a role in the maintenance and defense of the gut epithelial barrier, including inducing a release of antimicrobial peptides and chemokines in response to infection.
We describe the differentiation of healthy control hiPSCs into iHOs via the addition of specific cytokine combinations to their culture medium before embedding them into a basement membrane matrix-based prointestinal culture system. Once embedded, the iHOs are grown in media supplemented with Noggin, R-spondin-1, epidermal growth factor (EGF), CHIR99021, prostaglandin E2, and Y-27632 dihydrochloride monohydrate. Weekly passages by manual disruption of the iHO ultrastructure lead to the formation of budded iHOs, with some exhibiting a crypt/villus structure. All iHOs demonstrate a differentiated epithelium consisting of goblet cells, enteroendocrine cells, Paneth cells, and polarized enterocytes, which can be confirmed via immunostaining for specific markers of each cell subset, transmission electron microscopy (TEM), and quantitative PCR (qPCR). To model infection, Salmonella enterica serovar Typhimurium SL1344 are microinjected into the lumen of the iHOs and incubated for 90 min at 37 &#176;C, and a modified gentamicin protection assay is performed to identify the levels of intracellular bacterial invasion. Some iHOs are also pretreated with recombinant human IL-22 (rhIL-22) prior to infection to establish whether this cytokine is protective against Salmonella infection.

Using Human Induced Pluripotent Stem Cell-derived Intestinal Organoids to Study and Modify Epithelial Cell Protection Against Salmonella and Other Pathogens

Human induced pluripotent stem cell (hiPSC)-derived intestinal organoids offer exciting opportunities to model enteric diseases in vitro. We demonstrate the differentiation of hiPSCs into intestinal organoids (iHOs), the stimulation of these iHOs with cytokines, and the microinjection of Salmonella Typhimurium into the iHO lumen, enabling the study of an epithelial invasion by this pathogen.

The intestinal &#8216;organoid&#8217; (iHO) system, wherein 3-D structures representative of the epithelial lining of the human gut can be produced from ...

Immunology and Infection

Combining Human Organoids and Organ-on-a-Chip Technology to Model Intestinal Region-Specific Functionality

The intestinal mucosa is a complex physical and biochemical barrier that fulfills a myriad of important functions. It enables the transport, absorption, and metabolism of nutrients and xenobiotics while facilitating a symbiotic relationship with microbiota and restricting the invasion of microorganisms. Functional interaction between various cell types and their physical and biochemical environment is vital to establish and maintain intestinal tissue homeostasis. Modeling these complex interactions and integrated intestinal physiology in vitro is a formidable goal with the potential to transform the way new therapeutic targets and drug candidates are discovered and developed.
Organoids and Organ-on-a-Chip technologies have recently been combined to generate human-relevant intestine chips suitable for studying the functional aspects of intestinal physiology and pathophysiology in vitro. Organoids derived from the biopsies of the small (duodenum) and large intestine are seeded into the top compartment of an organ chip and then successfully expand&#160;as monolayers while preserving the distinct cellular, molecular, and functional features of each intestinal region. Human intestine tissue-specific microvascular endothelial cells are incorporated in the bottom compartment of the organ chip to recreate the epithelial-endothelial interface. This novel platform facilitates luminal exposure to nutrients, drugs, and microorganisms, enabling studies of intestinal transport, permeability, and host-microbe interactions.
Here, a detailed protocol is provided for the establishment of intestine chips representing the human duodenum (duodenum chip) and colon (colon chip), and their subsequent culture under continuous flow and peristalsis-like deformations. We demonstrate methods for assessing drug metabolism and CYP3A4 induction in duodenum chip using prototypical inducers and substrates. Lastly, we provide a step-by-step procedure&#160;for the in vitro modeling of interferon gamma (IFN&#947;)-mediated barrier disruption (leaky gut syndrome) in a colon chip, including methods for evaluating the alteration of paracellular permeability, changes in cytokine secretion, and transcriptomic profiling of the cells within the chip.

Biopsy-derived intestinal organoids and organ-on-a-chips technologies are combined into a microphysiological platform to recapitulate region-specific intestinal functionality.

The intestinal mucosa is a complex physical and biochemical barrier that fulfills a myriad of important functions. It enables the transport, absorption, ...

Bioengineering

Co-Culture of Murine Small Intestine Epithelial Organoids with Innate Lymphoid Cells

Complex co-cultures of organoids with immune cells provide a versatile tool for interrogating the bi-directional interactions that underpin the delicate balance of mucosal homeostasis. These 3D, multi-cellular systems offer a reductionist model for addressing multi-factorial diseases and resolving technical difficulties that arise when studying rare cell types such as tissue-resident innate lymphoid cells (ILCs). This article describes a murine system that combines small intestine organoids and small intestine lamina propria derived helper-like type-1 ILCs (ILC1s), which can be readily extended to other ILC or immune populations. ILCs are a tissue-resident population that is particularly enriched in the mucosa, where they promote homeostasis and rapidly respond to damage or infection. Organoid co-cultures with ILCs have already begun shedding light on new epithelial-immune signaling modules in the gut, revealing how different ILC subsets impact intestinal epithelial barrier integrity and regeneration. This protocol will enable further investigations into reciprocal interactions between epithelial and immune cells, which hold the potential to provide new insights into the mechanisms of mucosal homeostasis and inflammation.

This protocol offers detailed instructions for establishing murine small intestine organoids, isolating type-1 innate lymphoid cells from the murine small intestine lamina propria, and establishing 3-dimensional (3D) co-cultures between both cell types to study bi-directional interactions between intestinal epithelial cells and type-1 innate lymphoid cells.

Complex co-cultures of organoids with immune cells provide a versatile tool for interrogating the bi-directional interactions that underpin the delicate ...

A Protocol for Lentiviral Transduction and Downstream Analysis of Intestinal Organoids

Intestinal crypt-villus structures termed organoids, can be kept in sustained culture three dimensionally when supplemented with the appropriate growth factors. Since organoids are highly similar to the original tissue in terms of homeostatic stem cell differentiation, cell polarity and presence of all terminally differentiated cell types known to the adult intestinal epithelium, they serve as an essential resource in experimental research on the epithelium. The possibility to express transgenes or interfering RNA using lentiviral or retroviral vectors in organoids has increased opportunities for functional analysis of the intestinal epithelium and intestinal stem cells, surpassing traditional mouse transgenics in speed and cost. In the current video protocol we show how to utilize transduction of small intestinal organoids with lentiviral vectors illustrated by use of doxycylin inducible transgenes, or IPTG inducible short hairpin RNA for overexpression or gene knockdown. Furthermore, considering organoid culture yields minute cell counts that may even be reduced by experimental treatment, we explain how to process organoids for downstream analysis aimed at quantitative RT-PCR, RNA-microarray and immunohistochemistry. Techniques that enable transgene expression and gene knock down in intestinal organoids contribute to the research potential that these intestinal epithelial structures hold, establishing organoid culture as a new standard in cell culture.

In this video protocol we give a step by step explanation of lentiviral transduction in organoids of primary intestinal epithelium and of processing and downstream analysis of these cultures by quantitative RT-PCR, RNA-microarray and immunohistochemistry.

Intestinal crypt-villus structures termed organoids, can be kept in sustained culture three dimensionally when supplemented with the appropriate growth ...

Organoid-Derived Epithelial Monolayer: A Clinically Relevant In Vitro Model for Intestinal Barrier Function

In the past, intestinal epithelial model systems were limited to transformed cell lines and primary tissue. These model systems have inherent limitations as the former do not faithfully represent original tissue physiology, and the availability of the latter is limited. Hence, their application hampers fundamental and drug development research. Adult stem-cell-based organoids (henceforth referred to as organoids) are miniatures of normal or diseased epithelial tissue from which they are derived. They can be established very efficiently from different gastrointestinal (GI) tract regions, have long-term expandability, and simulate tissue- and patient-specific responses to treatments in vitro. Here, the establishment of intestinal organoid-derived epithelial monolayers has been demonstrated along with methods to measure epithelial barrier integrity, permeability and transport,&#160;antimicrobial protein secretion, as well as histology. Moreover, intestinal organoid-derived monolayers can be enriched with proliferating stem and transit-amplifying cells as well as with key differentiated epithelial cells. Therefore, they represent a model system that can be tailored to study the effects of compounds on target cells and their mode of action. Although organoid cultures are technically more demanding than cell lines, once established, they can reduce failures in the later stages of drug development as they truly represent in vivo epithelium complexity and interpatient heterogeneity.

Here, we describe the preparation of human organoid-derived intestinal epithelial monolayers for studying intestinal barrier function, permeability, and transport. As organoids represent original epithelial tissue response to external stimuli, these models combine the advantages of expandability of cell lines and the relevance and complexity of primary tissue.

In the past, intestinal epithelial model systems were limited to transformed cell lines and primary tissue. These model systems have inherent limitations ...

Rat Intestinal Crypts Isolation and Intestinal Organoids Generation

Generation and Manipulation of Rat Intestinal Organoids

When using organoids to assess physiology and cell fate decisions, it is important to use a model that closely recapitulates in vivo contexts. Accordingly, patient-derived organoids are used for disease modeling, drug discovery, and personalized treatment screening. Mouse intestinal organoids are commonly utilized to understand aspects of both intestinal function/physiology and stem cell dynamics/fate decisions. However, in many disease contexts, rats are often preferred over mice as a model due to their greater physiological similarity to humans in terms of disease pathophysiology. The rat model has been limited by a lack of genetic tools available in vivo, and rat intestinal organoids have proven fragile and difficult to culture long-term. Here, we build upon previously published protocols to robustly generate rat intestinal organoids from the duodenum and jejunum. We provide an overview of several downstream applications utilizing rat intestinal organoids, including functional swelling assays, whole mount staining, the generation of 2D enteroid monolayers, and lentiviral transduction. The rat organoid model provides a practical solution to the need of the field for an in vitro model which retains physiological relevance to humans, can be quickly genetically manipulated, and is easily obtained without the barriers involved in procuring human intestinal organoids.

Author Spotlight: Generation and Manipulation of Rat Intestinal Organoids  

Here, we present a protocol to generate rat intestinal organoids and use them in several downstream applications. Rats are often a preferred preclinical model, and the robust intestinal organoid system fills the need for an in vitro system to accompany in vivo studies.

When using organoids to assess physiology and cell fate decisions, it is important to use a model that closely recapitulates in vivo contexts. ...

Generation of hiPSC-Derived Intestinal Organoids for Developmental and Disease Modelling Applications

hiPSC-derived intestinal organoids are epithelial structures that self-assemble from differentiated cells into complex 3D structures, representative of the human intestinal epithelium, in which they exhibit crypt/villus-like structures. Here, we describe the generation of hiPSC-derived intestinal organoids by the stepwise differentiation of hiPSCs into definitive endoderm, which is then posteriorized to form hindgut epithelium before being transferred into 3D culture conditions. The 3D culture environment consists of extracellular matrix (ECM) (e.g., Matrigel or other compatible ECM) supplemented with SB202190, A83-01, Gastrin, Noggin, EGF, R-spondin-1 and CHIR99021. Organoids undergo passaging every 7 days, where they are mechanically disrupted before transfer to fresh extracellular matrix and allowed to expand. QPCR and immunocytochemistry confirm that hiPSC-derived intestinal organoids contain mature intestinal epithelial cell types including goblet cells, Paneth cells and enterocytes. Additionally, organoids show evidence of polarization by expression of villin localized on the apical surface of epithelial cells.
The resulting organoids can be used to model human intestinal development as well as numerous human intestinal diseases including inflammatory bowel disease. To model intestinal inflammation, organoids can be exposed to inflammatory mediators such as TNF-&#945;, TGF-&#946;, and bacterial LPS. Organoids exposed to proinflammatory cytokines display an inflammatory and fibrotic phenotype in response. Pairing of healthy versus hiPSCs derived from patients with IBD may be useful in understanding mechanisms driving IBD. This may reveal novel therapeutic targets and novel biomarkers to assist in early disease diagnosis.

This protocol allows for the differentiation of human pluripotent cells into intestinal organoids. The protocol mimics normal human development by differentiating cells into a population of definitive endoderm, hindgut endoderm and then intestinal epithelium. This makes the protocol suitable for studying both intestinal development as well as disease modelling applications.

hiPSC-derived intestinal organoids are epithelial structures that self-assemble from differentiated cells into complex 3D structures, representative of ...

Using Human Intestinal Organoids to Understand the Small Intestine Epithelium at the Single Cell Transcriptional Level

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Generation of hiPSC-Derived Intestinal Organoids for Developmental and Disease Modelling Applications