The authors thank Ava Zardynezhad for proofreading of the manuscript. This work is supported by the Canadian Institute of Health Research (CIHR, PJT-156035), and the Canada Foundation for Innovation for SL (32930), and by the National Natural Science Foundation of China for Yujia Lin (81901576).

All animal work needs to be approved by institutional and governmental ethics and animal handling committee.&#160; This is a non-survival surgery.&#160;
1. Preparation of materials
<ol>
	<li>Prepare 100 mL of 70% ethanol by mixing 70 mL of 100% ethanol with 30 mL of sterile water. Autoclave all surgical tools before surgery and keep the tools in 70% ethanol before and during the surgery to maintain sterilization.</li>
	<li>Prepare an injection apparatus.
	<ol>
		<li>Cut ~30 cm of polyethylen...

<ol>
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N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+spatially-organized+multicellular+innate+immune+response+in+lymph+nodes+limits+systemic+pathogen+spread.">A spatially-organized multicellular innate immune response in lymph nodes limits systemic pathogen spread.</a> Cell. 150, 1235-1248 (2012).</li><li>Gerner, M. Y., Torabi-Parizi, P., Germain, R. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strategically+localized+dendritic+cells+promote+rapid+T+cell+responses+to+lymph-borne+particulate+antigens.">Strategically localized dendritic cells promote rapid T cell responses to lymph-borne particulate antigens.</a> Immunity. 42, 172-185 (2015).</li><li>Moussion, C., Girard, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dendritic+cells+control+lymphocyte+entry+to+lymph+nodes+through+high+endothelial+venules.">Dendritic cells control lymphocyte entry to lymph nodes through high endothelial venules.</a> Nature. 479, 542-546 (2011).</li><li>Gretz, J. E., Norbury, C. C., Anderson, A. O., Proudfoot, A. E., Shaw, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lymph-borne+chemokines+and+other+low+molecular+weight+molecules+reach+high+endothelial+venules+via+specialized+conduits+while+a+functional+barrier+limits+access+to+the+lymphocyte+microenvironments+in+lymph+node+cortex.">Lymph-borne chemokines and other low molecular weight molecules reach high endothelial venules via specialized conduits while a functional barrier limits access to the lymphocyte microenvironments in lymph node cortex.</a> The Journal of Experimental Medicine. 192, 1425-1440 (2000).</li><li>Mebius, R. E., Breve, J., Duijvestijn, A. M., Kraal, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+function+of+high+endothelial+venules+in+mouse+lymph+nodes+stimulated+by+oxazolone.">The function of high endothelial venules in mouse lymph nodes stimulated by oxazolone.</a> Immunology. 71, 423-427 (1990).</li><li>Mebius, R. E., Streeter, P. R., Breve, J., Duijvestijn, A. M., Kraal, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+afferent+lymphatic+vessel+interruption+on+vascular+addressin+expression.">The influence of afferent lymphatic vessel interruption on vascular addressin expression.</a> Journal of Cell Biology. 115, 85-95 (1991).</li><li>Mebius, R. 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=Expression+of+GlyCAM-1,+an+endothelial+ligand+for+L-selectin,+is+affected+by+afferent+lymphatic+flow.">Expression of GlyCAM-1, an endothelial ligand for L-selectin, is affected by afferent lymphatic flow.</a> Journal of Immunology. 151, 6769-6776 (1993).</li><li>Drayton, D. L., Liao, S., Mounzer, R. H., Ruddle, N. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lymphoid+organ+development:+from+ontogeny+to+neogenesis.">Lymphoid organ development: from ontogeny to neogenesis.</a> Nature Immunology. 7, 344-353 (2006).</li><li>Tomei, A. A., Siegert, S., Britschgi, M. R., Luther, S. A., Swartz, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluid+flow+regulates+stromal+cell+organization+and+CCL21+expression+in+a+tissue-engineered+lymph+node+microenvironment.">Fluid flow regulates stromal cell organization and CCL21 expression in a tissue-engineered lymph node microenvironment.</a> Journal of Immunology. 183, 4273-4283 (2009).</li><li>Liao, S., Jones, D., Cheng, G., Padera, T. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+for+the+quantitative+measurement+of+collecting+lymphatic+vessel+contraction+in+mice.">Method for the quantitative measurement of collecting lymphatic vessel contraction in mice.</a> Journal of Biological Methods. 1, 6 (2014).</li><li>Lin, Y., 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=Perinodal+Adipose+Tissue+Participates+in+Immune+Protection+through+a+Lymphatic+Vessel-Independent+Route.">Perinodal Adipose Tissue Participates in Immune Protection through a Lymphatic Vessel-Independent Route.</a> Journal of Immunology. 201, 296-305 (2018).</li><li>Gardenier, J. 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=Diphtheria+toxin-mediated+ablation+of+lymphatic+endothelial+cells+results+in+progressive+lymphedema.">Diphtheria toxin-mediated ablation of lymphatic endothelial cells results in progressive lymphedema.</a> Journal of Clinical Investigation Insight. 1, 84095 (2016).</li></ol>

Blocking lymph flow will have broad applications in manipulating antigen delivery to the LN in healthy and diseased conditions. It is possible to use this method to control the timing of antigen delivery in order to study how continuous lymph flow regulates immune response in draining LNs. This method of lymph flow interruption can also be used to study how lymph impacts cell compartmentalization, cell activation, cell migration, and cell-cell interactions in the LN.
Mice specifically expressi...

The spatial organization of the lymphatic system provides structural and functional support to efficiently remove extracellular fluid and transport antigens and antigen-presenting cells (APCs) to the draining LNs. The initial lymphatic vessels (also named lymphatic capillaries) are highly permeable due to their discontinuous intercellular junctions, which facilitate the effective collection of fluids, cells, and other materials from surrounding extracellular spaces1. The initial lymphatic vessels merge into collecting lymphatic vessels, which have tight intercellular junctions, a continuous basement membrane, and lymphatic muscle coverage. Collecting lymphatic vessels are responsible for transporting collected lymph to the draining LNs and eventually returning lymph to the circulation2,3. The collecting lymphatic vessels that propel lymph into the draining LN are the afferent lymphatic vessels4,5,6,7. Obstruction of afferent lymphatic vessels can block lymph flow into the LNs, which is a useful technique when studying the function of lymph flow.
Previous studies have shown that lymph flow plays a significant role in transporting antigens and APCs, as well as maintaining LN homeostasis. It is well understood that tissue-derived APCs, typically activated migrating dendritic cells (DCs), travel through the afferent lymphatic vessels to the LN to activate T cells8. The idea that free-form antigens, such as microbes or soluble antigens, passively flow with lymph to the LN to activate LN-resident APCs has been gaining acceptance in the past decade9,10,11,12. Free-form antigens traveling with lymph take minutes after the infection to travel to the LN, and the LN-resident cell activation may occur within 20 min after the stimulation. This is much faster than the activation of migrating DCs, which takes more than 8 h to enter the draining LN9. Besides transporting antigens to initiate immune protection, lymph also carries cytokines and DCs to the LN to maintain its microenvironment, and to support immune cell homeostasis13,14. Previously, blocking lymph flow by suturing the afferent lymphatic vessels demonstrated that lymph is required to maintain the HEV phenotype required for supporting homeostatic T cell and B cell homing to the LN15,16,17. CCL21 is a critical chemokine that directs DC and T cell positioning in the LN8,18. Blocking lymph flow interrupts CCL21 expression in the LN and potentially interrupts DC and T cell positioning and/or interaction in the LN19. Thus, blocking lymph flow can directly or indirectly abrogate antigen/DC access to the draining LN by disrupting the LN microenvironment that regulates immune responses in the LN. To better investigate the function of lymph flow, an experimental protocol is presented (Figure 1) to block lymph flow in mice by suturing the afferent lymphatic vessels from the footpad to the pLN. This method can be an important technique for future studies on lymphatic function in healthy and diseased conditions.

<table>
	<tbody>
		<tr>
			<td>0.9% Sodium Chloride Saline</td>
			<td>Baxter</td>
			<td>JB1323</td>
			<td></td>
		</tr>
		<tr>
			<td>100% ethanol</td>
			<td>Greenfield Global</td>
			<td></td>
			<td>University of Calgary distribution services UN1170.</td>
		</tr>
		<tr>
			<td>Depilatory cream</td>
			<td>Nair</td>
			<td></td>
			<td>Nair Sensitive Formula Hair Removal Cr&#232;me with Sweet Almond Oil and Baby Oil, 200-ml. Or similar product.</td>
		</tr>
		<tr>
			<td>Evans Blue dye</td>
			<td>Sigma Life Science</td>
			<td>E2129-10G</td>
			<td>For 1 ml of Evans blue dye, add 0.1g Evans blue to 10 ml PBS. The Evens Blue solution will be filtered through 0.22 mm filters and kept sterile in 1ml aliquots.</td>
		</tr>
		<tr>
			<td>Fluorescein isothiocyanate isomer I (FITC)</td>
			<td>Sigma Life Science</td>
			<td>F7250-1G</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps Dumont #3</td>
			<td>WPI</td>
			<td>500337</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps Dumont #5</td>
			<td>WPI</td>
			<td>500233</td>
			<td></td>
		</tr>
		<tr>
			<td>Injection apparatus</td>
			<td></td>
			<td></td>
			<td>Connect one end of polyethylene tubing to 30G &#215; &#189; needle. Attach a 1ml TB syringe to the needle. Dislodge needle shaft from another 30G &#215; &#189; needle. Insert the blunt end of the 30G &#215; &#189; needle shaft into the other end of the tubing. The inside diameter of this tubing is 0.28mm. Thus, 1.6 cm of fluid in the tubing is 1 &#956;l.</td>
		</tr>
		<tr>
			<td>Insulin syringe</td>
			<td>Becton Dickinson and Company (BD)</td>
			<td>329461</td>
			<td></td>
		</tr>
		<tr>
			<td>IRIS Forcep straight</td>
			<td>WPI</td>
			<td>15914</td>
			<td></td>
		</tr>
		<tr>
			<td>IRIS scissors</td>
			<td>WPI</td>
			<td>14218-G</td>
			<td></td>
		</tr>
		<tr>
			<td>Ketamine</td>
			<td>Narketan</td>
			<td>DIN 02374994</td>
			<td>The suppliers of Ketamine and Xylazine are usually under institutional and governmental regulation.</td>
		</tr>
		<tr>
			<td>Needles (26Gx3/8)</td>
			<td>Becton Dickinson and Company (BD)</td>
			<td>305110</td>
			<td></td>
		</tr>
		<tr>
			<td>Needles (30Gx1/2)</td>
			<td>Becton Dickinson and Company (BD)</td>
			<td>305106</td>
			<td></td>
		</tr>
		<tr>
			<td>Paton Needle Holder</td>
			<td>ROBOZ</td>
			<td>RS6403</td>
			<td>Straight, Without Lock; Serrated</td>
		</tr>
		<tr>
			<td>Phosphate-Buffered Saline (PBS)</td>
			<td>Sigma Life Science</td>
			<td>P4417-100TAB</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyethylene tubing</td>
			<td>Becton Dickinson and Company (BD)</td>
			<td>427401</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical tape (1.25cmx9.1m )</td>
			<td>Transpore</td>
			<td>1527-0</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical tape (2.5cmx9.1m )</td>
			<td>Transpore</td>
			<td>1527-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Suture</td>
			<td>Davis and Geck CYANAMID Canada</td>
			<td>11/04</td>
			<td>0.7 metric monofilament polypropylene</td>
		</tr>
		<tr>
			<td>Syringe (1ml)</td>
			<td>Becton Dickinson and Company (BD)</td>
			<td>309659</td>
			<td></td>
		</tr>
		<tr>
			<td>VANNAS scissors</td>
			<td>World Precision Instruments (WPI)</td>
			<td>14122-G</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>Rompun</td>
			<td>DIN02169606</td>
			<td>The suppliers of Ketamine and Xylazine are usually under institutional and governmental regulation.</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dissecting microscope</td>
			<td>Olympus</td>
			<td></td>
			<td>Olympus S261 (522-STS OH141791) with light source: Olympus Highlight 3100</td>
		</tr>
		<tr>
			<td>Confocal microscope</td>
			<td>Leica</td>
			<td></td>
			<td>SP8</td>
		</tr>
	</tbody>
</table>

blocking lymph flow by suturing afferent lymphatic vessels in mice

Lymphatic vessels are critical in maintaining tissue fluid balance and optimizing immune protection by transporting antigens, cytokines, and cells to draining lymph nodes (LNs). Interruption of lymph flow is an important method when studying the function of lymphatic vessels. The afferent lymphatic vessels from the murine footpad to the popliteal lymph nodes (pLNs) are well-defined as the only routes for lymph drainage into the pLNs. Suturing these afferent lymphatic vessels can selectively prevent lymph flow to the pLNs. This method allows for interference in lymph flow with minimal damage to the lymphatic endothelial cells in the draining pLN, the afferent lymphatic vessels, as well as other lymphatic vessels around the area. This method has been used to study how lymph impacts high endothelial venules (HEV) and chemokine expression in the LN, and how lymph flows through the adipose tissue surrounding the LN in the absence of functional lymphatic vessels. With the growing recognition of the importance of lymphatic function, this method will have broader applications to further unravel the function of lymphatic vessels in regulating the LN microenvironment and immune responses.

Lymphatic vessel suture has been used in previous studies15,16,17,19, where it served as an important tool to study the function of lymph flow before the molecular biology of lymphatic vessels was better understood. Blocking lymph flow interrupts LN homeostasis, which leads to HEVs losing the critical gene expression needed for optimal lymphocyte homing to the LN15,...

Watch this Scientific Journal Video about Blocking Lymph Flow by Suturing Afferent Lymphatic Vessels in Mice at JoVE.com

Blocking Lymph Flow by Suturing Afferent Lymphatic Vessels in Mice

A protocol to block lymph flow by surgical suturing of afferent lymphatic vessels is presented.

Lymphatic vessels are critical in maintaining tissue fluid balance and optimizing immune protection by transporting antigens, cytokines, and cells to ...

This method interrupts lymph flow with minimal damage to lymphatic endothelial cells, and with precise control of blockade timing, it can be used to study how lymph flow impacts homeostasis and immune responses in the lymph node. Helping to demonstrate the procedure will be Jingna Xue, a graduate student from my laboratory. To prepare an injection apparatus, cut approximately 30 centimeters of polyethylene tubing.Connect the tip of needle A to one end of the tubing. Carefully dislodge another needle, and connect the broken side to the other end of polyethylene tubing. Then attach needle A to a one-milliliter tuberculin syringe.Immediately before use, prepare a 10:1 ketamine-xylazine mixture in saline. After anesthetizing the mouse by injecting 250 microliters of the ketamine/xylazine mixture intraperitoneally, ensure full anesthetization with a toe pinch. Shave the fur around the legs with hair clippers, then apply depilatory cream around the leg.After five minutes, wipe off the residual fur and the depilatory cream using a moist tissue, then clean the leg with sterile water. Spray 70%ethanol around the leg to sterilize the operating area. Place the mouse in a prone position, and use surgical tape to expose the operation area on the right leg.Intradermally inject five microliters of 1%Evans blue dye, or nine centimeters of the fluid from the injection apparatus tubing into the right foot pad of the mouse. Gently massage the footpad to help the fluid enter the lymphatic vessels. Under a dissecting microscope, locate an incision site five millimeters from the bottom edge of the popliteal fossa.Using a pair of scissors, make a small incision approximately five millimeters in length. Then use fine operation forceps to stretch the incision and expose the collecting lymphatic vessels. Identify both of the afferent lymphatic vessels leading to the popliteal lymph nodes.Using a needle holder, cautiously insert the suture needle between the afferent lymphatic vessels and the saphenous artery. Gently pull the needle out around the afferent lymphatic vessels. Carefully pull the suture string, leaving about two centimeters of the suture string behind.Use the needle holder to help tie a surgeon's knot. Gently massage the foot pad to ensure no Evans blue dye passes the suture site, then cut the excess string with scissors. Suture the other afferent lymphatic vessels, then close the skin incision with the same suture that was used for the lymphatic vessels.For the sham control, intradermally inject five microliters of 1%Evans blue dye in the left foot pad, and massage the foot pad. Open the skin with an incision, and then close the wound without suturing the vessel. When monitoring the mouse post-surgery, the right leg should show edema, with Evans blue dye spreading to the thigh, while the control leg will show Evans blue dye restricted to the foot pad.Immediately after the surgery, intradermally inject 10 microliters of 2%FITC in both the right foot pad and the left. Two, six, and 12 hours after FITC injection, collect the popliteal lymph nodes from the fossa of euthanized mice. Carefully remove the perinodal adipose tissue around the pLNs.Embed the pLNs in optimal cutting temperature compound with the medullary sinus area facing to the side of the cryo mold. Use a cryotome to prepare 20-micron frozen sections. To determine the FITC distribution in the pLNs, image the cryo-sections under a confocal microscope.Confocal images captured two, six, and 12 hours after FITC injection show substantially reduced FITC accumulation in the popliteal lymph nodes after suturing the afferent lymphatic vessels. The residual FITC in the pLNs was preferentially accumulated in the lymph node sinuses. Confocal images of the perinodal adipose tissue show when lymphatic vessels are blocked by suturing, FITC enters the tissue when the lymph node sinuses, but it's not effectively distributed throughout the lymph nodes.When attempting this method, it's important to remember that inserting the suture needle between the blood vessel and the lymphatic vessel is critical. Failure of this step may break the vessels. After performing this method, it's possible to immunize mice with infection or other immune stimulation to study how lymph flow regulates immune protection.The function of lymph flow is not well understood. This method can be used to study cell migrations in the lymph node in the absence of lymph flow.

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JoVE Journal

Immunology and Infection

5.2K vistas.  Harbin Medical University. Este método interrumpe el flujo linfático con un daño mínimo a las células endoteliales linfáticas, y con un control preciso de la sincronización del bloqueo, se puede utilizar para estudiar cómo el flujo linfático afecta a la homeostasis y las respuestas inmunitarias en el ganglio linfático. Ayudar a demostrar el procedimiento será Jingna Xue, una estudiante graduada de mi laboratorio. Para preparar un aparato de inyección, corte aproximadamente 30 centímetros de tubo de polieti...