Name: observing islet function and islet-immune cell interactions in live pancreatic tissue slices
Uploaded: 2021-04-12T13:30:00
Description: Watch this Scientific Journal Video about Observing Islet Function and Islet-Immune Cell Interactions in Live Pancreatic Tissue Slices at JoVE.com

This work was funded by NIH grants R01 DK123292, T32 DK108736, UC4 DK104194, UG3 DK122638, and P01 AI042288. This research was performed with the support of the Network for Pancreatic Organ donors with Diabetes (nPOD; RRID:SCR_014641), a collaborative type 1 diabetes research project sponsored by JDRF (nPOD: 5-SRA-2018-557-Q-R), and The Leona M. &#38; Harry B. Helmsley Charitable Trust (Grant #2018PG-T1D053). The content and views expressed are the responsibility of the authors and do not necessarily reflect the official view of nPOD. Organ Procurement Organizations (OPO) partnering with nPOD to provide research resources are listed at http://www.jdrfnpod.org/for-partners/npod-partners/. Thank you to Dr. Kevin Otto, University of Florida, for providing the vibratome used to generate mouse slices.&#160;

NOTES: All experimental protocols using mice were approved by the University of Florida Animal Care and Use Committee (201808642). Human pancreatic sections from tissue donors of both sexes were obtained via the Network for Pancreatic Organ Donors with Diabetes (nPOD) tissue bank, University of Florida. Human pancreata were harvested from cadaveric organ donors by certified organ procurement organizations partnering with nPOD in accordance with organ donation laws and regulations and classified as &#34;Non-Human Subjects...

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The objective of this protocol is to explicate the generation of pancreas slices and the procedures needed to employ the slices in functional and immunological studies. There are many benefits to using live pancreatic slices. However, there are several critical steps that are essential for the tissue to remain viable and useful during the described experiment protocols. It is imperative to work quickly. The length of time between injecting the pancreas and generating the slices on the vibratome should be minimized to mai...

Involvement of the pancreas is pathognomonic to diseases such as pancreatitis, T1D, and T2D1,2,3. The study of function in isolated islets usually involves removal of the islets from their surrounding environment4. The live pancreatic tissue slice method was developed to allow for the study of pancreatic tissue while maintaining intact islet microenvironments and avoiding the use of stressful islet isolation procedures5,6,7. Pancreatic tissue slices from human donor tissue have been successfully used to study T1D and have demonstrated processes of beta cell loss and dysfunction in addition to immune cell infiltration8,9,10,11,12,13. The live pancreatic tissue slice method can be applied to both mouse and human pancreatic tissue5,6,8. Human pancreatic tissue slices from organ donor tissues are obtained through a collaboration with the Network for Pancreatic Organ Donors with Diabetes (nPOD). Mouse slices can be generated from a variety of different mouse strains.
This protocol will focus on non-obese diabetic-recombination activating gene-1-null (NOD.Rag1-/-) and T cell receptor transgenic (AI4) (NOD.Rag1-/-.AI4&#945;/&#946;) mouse strains. NOD.Rag1-/- mice are unable to develop T and B cells due to a disruption in the recombination-activating gene 1 (Rag1)14. NOD.Rag1-/-.AI4&#945;/&#946; mice are used as a model for accelerated type 1 diabetes because they produce a single T cell clone that targets an epitope of insulin, resulting in consistent islet infiltration and rapid disease development15. The protocol featured here describes procedures for functional and immunological studies using live human and mouse pancreatic slices through the application of confocal microscopy approaches. The techniques described herein include viability assessments, islet identification and location, cytosolic Ca2+ recordings, as well as staining and identification of immune cell populations.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>#3 Style Scalpel Handle</td>
			<td>Fisherbrand</td>
			<td>12-000-163</td>
			<td></td>
		</tr>
		<tr>
			<td>1 M HEPES</td>
			<td>Fisher Scientific</td>
			<td>BP299-100</td>
			<td>HEPES Buffer, 1M Solution</td>
		</tr>
		<tr>
			<td>10 cm Untreated Culture Dish</td>
			<td>Corning</td>
			<td>430591</td>
			<td></td>
		</tr>
		<tr>
			<td>10 mL Luer-Lok Syringe</td>
			<td>BD</td>
			<td>301029</td>
			<td>BD Syringe with Luer-Lok Tips</td>
		</tr>
		<tr>
			<td>27 G Needle</td>
			<td>BD</td>
			<td>BD 305109</td>
			<td>BD General Use and PrecisionGlide Hypodermic Needles</td>
		</tr>
		<tr>
			<td>35 mm coverglass-bottom Petri dish</td>
			<td>Ibidi</td>
			<td>81156</td>
			<td>&#181;-Dish 35 mm, high</td>
		</tr>
		<tr>
			<td>50 mL syringe</td>
			<td>BD</td>
			<td>309653</td>
			<td></td>
		</tr>
		<tr>
			<td>8-well chambered coverglass</td>
			<td>Ibidi</td>
			<td>80826</td>
			<td>&#181;-Slide 8 Well</td>
		</tr>
		<tr>
			<td>APC anti-mouse CD8a antibody</td>
			<td>Biolegend</td>
			<td>100712</td>
			<td></td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>Fisher Scientific</td>
			<td>199898</td>
			<td></td>
		</tr>
		<tr>
			<td>Calcium chloride</td>
			<td>Sigma</td>
			<td>C5670</td>
			<td>CaCl2</td>
		</tr>
		<tr>
			<td>Calcium chloride dihydrate</td>
			<td>Sigma</td>
			<td>C7902</td>
			<td>CaCl2 (dihydrate)</td>
		</tr>
		<tr>
			<td>Compact Digital Rocker</td>
			<td>Thermo Fisher Scientific</td>
			<td>88880020</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal laser-scanning microscope</td>
			<td>Leica</td>
			<td>SP8</td>
			<td>Pinhole&#8201;= 1.5-2 airy units; acquired with 10x/0.40 numerical aperture HC PL APO CS2 dry and 20x/0.75 numerical aperture HC PL APO CS2 dry objectives at 512&#8201;&#215;&#8201;512 pixel resolution</td>
		</tr>
		<tr>
			<td>D-(+)-Glucose</td>
			<td>Sigma</td>
			<td>G7021</td>
			<td>C6H12O6</td>
		</tr>
		<tr>
			<td>ddiH2O</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dithizone</td>
			<td>Sigma-Aldrich</td>
			<td>D5130-10G</td>
			<td></td>
		</tr>
		<tr>
			<td>DMSO</td>
			<td>Invitrogen</td>
			<td>D12345</td>
			<td>Dimethyl sulfoxide</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Decon Laboratories</td>
			<td>2805</td>
			<td></td>
		</tr>
		<tr>
			<td>Falcon 35 mm tissue culture dish</td>
			<td>Corning</td>
			<td>353001</td>
			<td>Falcon Easy-Grip Tissue Culture Dishes</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Gibco</td>
			<td>10082147</td>
			<td></td>
		</tr>
		<tr>
			<td>Feather No. 10 Surgical Blade</td>
			<td>Electron Microscopy Sciences</td>
			<td>7204410</td>
			<td></td>
		</tr>
		<tr>
			<td>fluo-4-AM</td>
			<td>Invitrogen</td>
			<td>F14201</td>
			<td>cell-permeable Ca2+ indicator</td>
		</tr>
		<tr>
			<td>Gel Control Super Glue</td>
			<td>Loctite</td>
			<td>45198</td>
			<td></td>
		</tr>
		<tr>
			<td>Graefe Forceps</td>
			<td>Fine Science Tools</td>
			<td>11049-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Hardened Fine Scissors</td>
			<td>Fine Science Tools</td>
			<td>14090-09</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS</td>
			<td>Gibco</td>
			<td>14025092</td>
			<td>Hanks Balanced Salt Solution</td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Sigma</td>
			<td>H4034</td>
			<td>C8H18N2O4S</td>
		</tr>
		<tr>
			<td>Ice bucket</td>
			<td>Fisherbrand</td>
			<td>03-395-150</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Patterson Veterinary</td>
			<td>NDC 14043-704-05</td>
			<td></td>
		</tr>
		<tr>
			<td>Johns Hopkins Bulldog Clamp</td>
			<td>Roboz Surgical Store</td>
			<td>RS-7440</td>
			<td>&#160;Straight; 500-900 Grams Pressure; 1.5&#34; Length</td>
		</tr>
		<tr>
			<td>Kimwipes</td>
			<td>Kimberly-Clark Professional</td>
			<td>34705</td>
			<td>Kimtech Science&#8482; Kimwipes&#8482; Delicate Task Wipers, 2-Ply</td>
		</tr>
		<tr>
			<td>LIVE/DEAD Viability/Cytotoxicity Kit</td>
			<td>Invitrogen</td>
			<td>L3224</td>
			<td>This kit contains the calcein-AM live cell dye.</td>
		</tr>
		<tr>
			<td>Low glucose DMEM</td>
			<td>Corning</td>
			<td>10-014-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnesium chloride hexahydrate</td>
			<td>Sigma</td>
			<td>M9272</td>
			<td>MgCl2 (hexahydrate)</td>
		</tr>
		<tr>
			<td>Magnesium sulfate heptahydrate</td>
			<td>Sigma</td>
			<td>M2773</td>
			<td>MgSO4 (heptahydrate)</td>
		</tr>
		<tr>
			<td>Magnetic Heated Platform</td>
			<td>Warner Instruments</td>
			<td>PM-1</td>
			<td>Platform for imaging chamber for dynamic stimulation recordings</td>
		</tr>
		<tr>
			<td>Microwave</td>
			<td>GE</td>
			<td>JES1460DSWW</td>
			<td></td>
		</tr>
		<tr>
			<td>Nalgene Syringe Filter</td>
			<td>Thermo Fisher Scientific</td>
			<td>726-2520</td>
			<td></td>
		</tr>
		<tr>
			<td>No.4 Paintbrush</td>
			<td>Michaels</td>
			<td>10269140</td>
			<td></td>
		</tr>
		<tr>
			<td>Open Diamond Bath Imaging Chamber</td>
			<td>Warner Instruments</td>
			<td>RC-26</td>
			<td>Imaging chamber for dynamic stimulation recordings</td>
		</tr>
		<tr>
			<td>Oregon Green 488 BAPTA-1-AM</td>
			<td>Invitrogen</td>
			<td>O6807</td>
			<td>cell-permeable Ca2+ indicator</td>
		</tr>
		<tr>
			<td>Overnight imaging chamber</td>
			<td>Okolab</td>
			<td>H201-LG</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Thermo Fisher Scientific</td>
			<td>20012050</td>
			<td>To make agarose for slice generation</td>
		</tr>
		<tr>
			<td>PE-labeled insulin tetramer</td>
			<td>Emory Tetramer Research Core</td>
			<td>sequence YAIENYLEL</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin Streptomycin</td>
			<td>Gibco</td>
			<td>15140122</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium chloride</td>
			<td>Sigma</td>
			<td>P5405</td>
			<td>KCl</td>
		</tr>
		<tr>
			<td>Potassium phosphate monobasic</td>
			<td>Sigma</td>
			<td>P5655</td>
			<td>KH2PO4</td>
		</tr>
		<tr>
			<td>Razor Blades</td>
			<td>Electron Microscopy Sciences</td>
			<td>71998</td>
			<td>For Vibratome; Double Edge Stainless Steel, uncoated</td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>Gibco</td>
			<td>11875093</td>
			<td></td>
		</tr>
		<tr>
			<td>SeaPlaque low melting-point agarose</td>
			<td>Lonza</td>
			<td>50101</td>
			<td>To make agarose for slice generation</td>
		</tr>
		<tr>
			<td>Slice anchor</td>
			<td>Warner Instruments</td>
			<td>64-1421</td>
			<td></td>
		</tr>
		<tr>
			<td>Slice anchor (dynamic imaging)</td>
			<td>Warner Instruments</td>
			<td>640253</td>
			<td>Slice anchor for dynamic imaging chamber</td>
		</tr>
		<tr>
			<td>Sodium bicarbonate</td>
			<td>Sigma</td>
			<td>S5761</td>
			<td>NaHCO3</td>
		</tr>
		<tr>
			<td>Sodium chloride</td>
			<td>Sigma</td>
			<td>S5886</td>
			<td>NaCl</td>
		</tr>
		<tr>
			<td>Sodium phosphate monohydrate</td>
			<td>Sigma</td>
			<td>S9638</td>
			<td>NaH2PO4 (monohydrate)</td>
		</tr>
		<tr>
			<td>Soybean Trypsin Inhibitor</td>
			<td>Sigma</td>
			<td>T6522-1G</td>
			<td>Trypsin inhibitor from Glycine max (soybean)</td>
		</tr>
		<tr>
			<td>Stage Adapter</td>
			<td>Warner Instruments</td>
			<td>SA-20MW-AL</td>
			<td>To fit imaging chamber for dynamic stimulation recordings on the microscope stage</td>
		</tr>
		<tr>
			<td>Stage-top incubator</td>
			<td>Okolab</td>
			<td>H201</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereoscope</td>
			<td>Leica</td>
			<td>IC90 E MSV266</td>
			<td></td>
		</tr>
		<tr>
			<td>SYTOX Blue Dead Cell Stain</td>
			<td>Invitrogen</td>
			<td>S34857</td>
			<td>blue-fluorescent nucleic acid stain</td>
		</tr>
		<tr>
			<td>Transfer Pipet</td>
			<td>Falcon</td>
			<td>357575</td>
			<td>Falcon&#8482; Plastic Disposable Transfer Pipets</td>
		</tr>
		<tr>
			<td>Valve Control System</td>
			<td>Warner Instruments</td>
			<td>VCS-8</td>
			<td>System for dynamic stimulation recordings</td>
		</tr>
		<tr>
			<td>Vibratome VT1000 S</td>
			<td>Leica</td>
			<td>VT1000 S</td>
			<td></td>
		</tr>
		<tr>
			<td>Water bath</td>
			<td>Fisher Scientific</td>
			<td>FSGPD02</td>
			<td>Fisherbrand Isotemp General Purpose Deluxe Water Bath GPD 02</td>
		</tr>
	</tbody>
</table>

observing islet function and islet-immune cell interactions in live pancreatic tissue slices

Live pancreatic tissue slices allow for the study of islet physiology and function in the context of an intact islet microenvironment. Slices are prepared from live human and mouse pancreatic tissue embedded in agarose and cut using a vibratome. This method allows for the tissue to maintain viability and function in addition to preserving underlying pathologies such as type 1 (T1D) and type 2 diabetes (T2D). The slice method enables new directions in the study of the pancreas through the maintenance of the complex structures and various intercellular interactions that comprise the endocrine and exocrine tissues of the pancreas. This protocol demonstrates how to perform staining and time-lapse microscopy of live endogenous immune cells within pancreatic slices along with assessments of islet physiology. Further, this approach can be refined to discern immune cell populations specific for islet cell antigens using major histocompatibility complex-multimer reagents.

This protocol will yield live pancreatic tissue slices suitable for both functionality studies and immune cell recordings. Slice appearance in both brightfield and under reflected light are shown in Figure 1A,B. As discussed, islets can be found in slices using reflected light due to their increased granularity that occurs because of their insulin content (Figure 1C) and are clearly observed compared to the background tissue when reflected light...

Watch this Scientific Journal Video about Observing Islet Function and Islet-Immune Cell Interactions in Live Pancreatic Tissue Slices at JoVE.com

Observing Islet Function and Islet-Immune Cell Interactions in Live Pancreatic Tissue Slices

This study presents the application of live pancreatic tissue slices to the study of islet physiology and islet-immune cell interactions.

Live pancreatic tissue slices allow for the study of islet physiology and function in the context of an intact islet microenvironment. Slices are prepared ...

Our protocol will help answer the impact that immune cell interactions have on islet functionality. The live pancreatic tissue slice method allows for islet physiology and function to be studied while maintaining the tissues underlying pathologies and native microenvironment. This method could provide insight into the disease processes of pancreatic illnesses, such as pancreatitis, type I diabetes, and type II diabetes.To begin, arrange the blocks on the specimen holder in such a way that they do not exceed blade width, ensuring that the blade can move forward the least possible distance when the vibratome moves slowly. Apply a line of super glue on the specimen holder, making a thin layer using the end of the glue dispenser, then flip the tissue blocks onto the glue so that the side close to the tissue faces upward. Gently push down the blocks and let the glue dry for three minutes.Next, attach the plate to the vibratome with a screw and adjust the blade height and distance being traveled so that the blade moves over the length of blocks and just barely above them. Gently nudge the blocks with the forceps to check that the glue has dried, and then fill the vibratome tray with a chilled extracellular solution until the blade is covered. Set the vibratome to make slices of 120 micrometer thickness and start it, then observe the slices coming off the tissue blocks.Lift the slices when they float off the block by placing a paintbrush or forceps below them and place the slices in Krebs-Ringer bicarbonate buffer containing three millimolar D-glucose and trypsin inhibitor. Place the plates containing the slices on a rocker and incubate at room temperature for an hour at 25 RPM. If the slices need to be kept for longer, place the slices in 15 milliliters of slice culture medium and place the plate in an incubator.Incubate the prepared slices at 37 degree Celsius for same day studies or transfer the slices that are cultured at 24 degree Celsius overnight to 37 degree Celsius for at least one hour before the experiment. Switch on the microscope at least one hour before the recording and equilibrate the stage top incubator to 37 degree Celsius. Secure the cover glass bottom Petri dish containing the slice on the stage.Focus the microscope by setting the 10X objective in the brightfield mode and locate the islets using the bright field mode by looking for orange brown colored ovals within the slice. Switch the microscope to confocal imaging by pressing the CS button on the microscope's touch screen controller. To view the islets using reflectance, turn on the 638 laser detector and PMT detector.Set the laser power between one and 2%and turn off the notch filters. Use the 405 nanometer laser and PMT detector to observe the nucleic acid stain. The hybrid detector for the CD8 antibody detection and the 488 nanometers laser and hybrid detector to view the insulin tetramer.Center the islet of interest in the field of view using the X and Y knobs of the stage controller. Once an islet of interest is located, switch to the 20X objective and zoom in so the islet takes up most of the frame. Take a z-stack of the islet, then find the best optical sections where to the cells are alive and any surrounding immune cells are in focus.Set the microscope to record in XYZT mode and optimize the settings to record a z-stack of the selected steps every 20 minutes over a period of several hours. The islets in a pancreatic tissue slice were visualized using brightfield and reflected light microscopy. The insulin in the islets increases the granularity and causes absorption of large amounts of reflected light, increasing the visibility of the islets.The viability of a live human pancreatic tissue slice was assessed by staining. The live cells are indicated in green and the dead cells in blue. Another positive indicator for viability is observable basal activity.When a live pancreatic slice was loaded with a cell permeable calcium indicator, glucose stimulation was observed in both mouse and human pancreatic slices. The fluorescence of individual cells during glucose stimulation was also quantified. Intact and diseased islets were observed using dithizone staining and reflected light microscopy.The diseased islets begin to lose granularity due to immune cell infiltration and cell death. Immune cell populations can be identified using CD8 antibodies and insulin tetramer staining. Co-staining indicates that the cells are effector T-cell that are specifically targeting the insulin antigen.The most critical thing to remember in this procedure is to keep the slices in solutions protease inhibitor at all times. Following this procedure, numerous functionality in immune cell experiments can be performed allowing for the effect of immune cell interactions and islet function to be studied.

Research

JoVE Journal

Immunology and Infection

Use of an Optical Trap for Study of Host-Pathogen Interactions for Dynamic Live Cell Imaging

Dynamic live cell imaging allows direct visualization of real-time interactions between cells of the immune system1, 2; however, the lack of spatial and ...

Single Cell Measurements of Vacuolar Rupture Caused by Intracellular Pathogens

Shigella flexneri are pathogenic bacteria that invade host cells entering into an endocytic vacuole. Subsequently, the rupture of this membrane-enclosed ...

Visualizing Protein-DNA Interactions in Live Bacterial Cells Using Photoactivated Single-molecule Tracking

Protein-DNA interactions are at the heart of many fundamental cellular processes. For example, DNA replication, transcription, repair, and chromosome ...

Evaluation of the Efficacy And Toxicity of RNAs Targeting HIV-1 Production for Use in Gene or Drug Therapy

Small RNA therapies targeting post-integration steps in the HIV-1 replication cycle are among the top candidates for gene therapy and have the potential ...

Precision-cut Mouse Lung Slices to Visualize Live Pulmonary Dendritic Cells

Inhalation of allergens and pathogens elicits multiple changes in a variety of immune cell types in the lung. Flow cytometry is a powerful technique for ...

Ex Vivo Infection of Human Lymphoid Tissue and Female Genital Mucosa with Human Immunodeficiency Virus 1 and Histoculture

Ex Vivo Infection of Human Lymphoid Tissue and Female Genital Mucosa with Human Immunodeficiency Virus 1 and Histoculture

Histocultures allow studying intercellular interactions within human tissues, and they can be employed to model host-pathogen interactions under ...

Electrochemiluminescence Assays for Human Islet Autoantibodies

Pinpointing islet autoantibodies associated with type 1 diabetes (T1D) leads the way to project and deter this disease in the general population. A novel ...

A Murine Pancreatic Islet Cell-based Screening for Diabetogenic Environmental Chemicals

Exposure to certain environmental chemicals in human and animals has been found to cause cellular damage of the pancreatic &#946; cells which will lead to ...

Determination of Regulatory T Cell Subsets in Murine Thymus, Pancreatic Draining Lymph Node and Spleen Using Flow Cytometry

Our immune system consists of a number and variety of immune cells including regulatory T cells (Treg) cells. Treg cells can be divided into two subsets, ...

Live-Cell Fluorescence Microscopy to Investigate Subcellular Protein Localization and Cell Morphology Changes in Bacteria

Investigations of factors influencing cell division and cell shape in bacteria are commonly performed in conjunction with high-resolution fluorescence ...