Name: retrograde parotid gland infusion through stensen's duct in a non-human primate for vectored gene delivery
Uploaded: 2021-08-12T14:00:00
Description: Watch this Scientific Journal Video about Retrograde Parotid Gland Infusion through Stensen's Duct in a Non-Human Primate for Vectored Gene Delivery at JoVE.com

The authors want to thank Mr. Cagney Gentry for his audiovisual support in filming the procedure. We also want to acknowledge the Hefner VA medical center for academic support in pursuit of this project.

All procedures were performed at Wake Forest School of Medicine Clarkson Campus for animal studies. The Institutional Animal Care and Use Committee (IACUC) was consulted for ethical considerations and details of the procedures was submitted for review. Wake Forest IACUC approved our study protocol and all procedures were done under IACUC approved protocol #A17-147.
1. Preparing the infusion device
<ol>
	<li>Cut size 10 Polyethylene Tube (PET10) into 25 cm lengths using a pair of scissors.</l...

<ol>
	<li>Isenman, L., Liebow, C., Rothman, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+secretion+of+mammalian+digestive+enzymes+by+exocrine+glands.">The secretion of mammalian digestive enzymes by exocrine glands.</a> The American Journal of Physiology. 276, 223-232 (1999).</li><li>Perez, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salivary+epithelial+cells:+An+unassuming+target+site+for+gene+therapeutics.">Salivary epithelial cells: An unassuming target site for gene therapeutics.</a> The International Journal of Biochemistry &amp; Cell Biology. 42, 773-777 (2010).</li><li>Kochel, T. 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+dengue+virus+serotype-1+DNA+vaccine+induces+virus+neutralizing+antibodies+and+provides+protection+from+viral+challenge+in+Aotus+monkeys.">A dengue virus serotype-1 DNA vaccine induces virus neutralizing antibodies and provides protection from viral challenge in Aotus monkeys.</a> Vaccine. 18, 3166-3173 (2000).</li><li>Ponzio, T. A., Sanders, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+salivary+gland+as+a+target+for+enhancing+immunization+response.">The salivary gland as a target for enhancing immunization response.</a> Tropical Diseases, Travel Medicine and Vaccines. 3, 4 (2017).</li><li>Baum, B. 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=Early+responses+to+adenoviral-mediated+transfer+of+the+aquaporin-1+cDNA+for+radiation-induced+salivary+hypofunction.">Early responses to adenoviral-mediated transfer of the aquaporin-1 cDNA for radiation-induced salivary hypofunction.</a> Proceedings of the National Academy of Sciences of the United States of America. 109, 19403-19407 (2012).</li><li>Voutetakis, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sorting+of+Transgenic+Secretory+Proteins+in+Rhesus+Macaque+Parotid+Glands+After+Adenovirus-Mediated+Gene+Transfer.">Sorting of Transgenic Secretory Proteins in Rhesus Macaque Parotid Glands After Adenovirus-Mediated Gene Transfer.</a> Human Gene Therapy. 19, 1401-1405 (2008).</li><li>Niedzinski, E. 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=Enhanced+systemic+transgene+expression+after+nonviral+salivary+gland+transfection+using+a+novel+endonuclease+inhibitor/DNA+formulation.">Enhanced systemic transgene expression after nonviral salivary gland transfection using a novel endonuclease inhibitor/DNA formulation.</a> Gene Therapy. 10, 2133-2138 (2003).</li><li>Niedzinski, E. 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=Zinc+Enhancement+of+Nonviral+Salivary+Gland+Transfection.">Zinc Enhancement of Nonviral Salivary Gland Transfection.</a> Molecular Therapy. 7, 396-400 (2003).</li><li>Samuni, Y., Baum, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+delivery+in+salivary+glands:+From+the+bench+to+the+clinic.">Gene delivery in salivary glands: From the bench to the clinic.</a> Biochimica et Biophysica Acta - Molecular Basis of Disease. , (2011).</li><li>Voutetakis, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adeno-Associated+Virus+Serotype+2-Mediated+Gene+Transfer+to+The+Parotid+Glands+of+Nonhuman+Primates.">Adeno-Associated Virus Serotype 2-Mediated Gene Transfer to The Parotid Glands of Nonhuman Primates.</a> Human Gene Therapy. 18, 142-150 (2007).</li></ol>

Here we describe a protocol of retrograde infusion into the parotid gland through Stensen&#39;s Duct. The methodology described offers guidance that can potentially be used by researchers exploring the utility of salivary tissue as a site for gene therapy and other applications.
There are multiple critical steps to ensure the success of the procedure. First and foremost, all the procedural steps should be completed gently. Forceful bracing of the mouth could result in mandibular subluxation. F...

While salivary glands are well known for their exocrine production of saliva, researchers have long recognized their ability to secrete proteins directly into the bloodstream1, making them a potential target for gene therapy for systemic administration, such as replacement hormones or antibody production. In fact, salivary glands offer several advantages over other tissue targets, such as the inherent ability to produce proteins for secretion (a property muscles lack), heavy encapsulation that can limit vector diffusion, and well-differentiated tissue providing stability for non-integrating vectors. Furthermore, in the event of a serious adverse event, salivary glands are not critical for life and can be surgically removed. While not immediately intuitive, parotid glands are also easily accessible from the mouth through their main excretory duct, Stensen&#39;s Duct2.
Given the advantages of salivary tissue for gene therapy, there is increasing interest in exploring this tissue target. Numerous studies have already been performed in rodent, canine, and non-human primate models and at least one human clinical trial is underway3,4,5. To further explore and develop the utility of this tissue target for gene therapy purposes, more non-human primate studies will need to be performed. This paper describes a method for accessing the parotid glands through Stensen&#39;s Duct to deliver a vectored gene for transduction in the non-human primate model. To visibly demonstrate the delivery of the infusate and the anatomy of the duct as it enters the gland, fluoroscopy using radiocontrast was performed. To demonstrate successful transduction of a vector, an Adenovirus serotype 5 (Ad5) vectored egfp gene was used. Ad5 is a well-described vector capable of transducing salivary tissue. Although it is too immunogenic for ultimate clinical use, an Ad5 vector was chosen for this demonstration study to assure efficient transduction. Evaluating Enhanced Green Fluorescent Protein (EGFP) production is a well-described method to demonstrate successful transcription and translation of a vectored gene following transduction and was done here.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>500 &#181;L U100 syringes with 30-gauge needles</td>
			<td>Becton Dickinson</td>
			<td>328466</td>
			<td>fixed needle for less waste</td>
		</tr>
		<tr>
			<td>Adhesive (e.g., Ethicon Dermabond)</td>
			<td>Various</td>
			<td></td>
			<td>Cyanoacrylate adhesive to seal and keep the tubing in the duct during infusion.</td>
		</tr>
		<tr>
			<td>Atropine injectable solution</td>
			<td>Patterson Veterinary</td>
			<td>07 869-6061</td>
			<td>Atropine inj. 0.54 mg/mL</td>
		</tr>
		<tr>
			<td>BD Ultra-Fine Insulin Syringes 30G</td>
			<td>Walmart</td>
			<td>N/A</td>
			<td>Avilable in 0.5 mL and 1.0 mL sizes.</td>
		</tr>
		<tr>
			<td>Cyanoacrylate (medical glue)</td>
			<td>Ethicon</td>
			<td>DNX12</td>
			<td>Dermabond topical skin adhesive</td>
		</tr>
		<tr>
			<td>Dental loops with light</td>
			<td>Amazon (DDP)</td>
			<td>B012M3IV80</td>
			<td>Used to enhance visualization of Stensen&#39;s duct papilla</td>
		</tr>
		<tr>
			<td>Infant Lacrimal Dilator</td>
			<td>Surgipro</td>
			<td>SPOI-137</td>
			<td></td>
		</tr>
		<tr>
			<td>Ketamine injectable solution</td>
			<td>Patterson Veterinary</td>
			<td>07-803-6637</td>
			<td>Ketaset inj. 100 mg/mL</td>
		</tr>
		<tr>
			<td>Lacrimal Dilator</td>
			<td>Surgipro</td>
			<td>SPOI-132</td>
			<td>Used to dialate the Stensen&#39;s duct.</td>
		</tr>
		<tr>
			<td>Midazolam injectable solution</td>
			<td>Patterson Veterinary</td>
			<td>07 890-6698</td>
			<td>Midazolam inj. 5mg/mL</td>
		</tr>
		<tr>
			<td>Pair of scissors</td>
			<td>Amazon (DDP)</td>
			<td>N/A</td>
			<td>Used to cut PET10 tube</td>
		</tr>
		<tr>
			<td>Polyethylene Tubing (PE-10)</td>
			<td>Scientific Comodities, Inc</td>
			<td>BB31695-PE/1</td>
			<td>Tubing connecting the 30G syringe and inserted into the duct.</td>
		</tr>
		<tr>
			<td>Q-tips</td>
			<td>Walmart</td>
			<td>N/A</td>
			<td>Used to spread cyanoacrylate on the cheek</td>
		</tr>
		<tr>
			<td>Size 10 Polyethylene Tube (PET 10)</td>
			<td>Scientific Commodities</td>
			<td>BB31695-PE/1</td>
			<td>low density polyethylene tubing</td>
		</tr>
		<tr>
			<td>Small Animal Mouth Opener</td>
			<td>Amazon (DDP)</td>
			<td>B01F3LVJXC</td>
			<td>Used to keep the animal&#39;s mouth open.</td>
		</tr>
		<tr>
			<td>Tweezers</td>
			<td>Amazon (DDP)</td>
			<td>N/A</td>
			<td>Used to insert PET10 tube into Stenson&#39;s duct</td>
		</tr>
		<tr>
			<td>Zinc Chloride</td>
			<td>Sigma-Aldrich</td>
			<td>7646-86-7</td>
			<td>Included in plasmid DNA infusates</td>
		</tr>
	</tbody>
</table>

retrograde parotid gland infusion through stensen's duct in a non-human primate for vectored gene delivery

Salivary glands are an attractive tissue target for gene therapy with promising results already leading to human trials. They are inherently capable of secreting proteins into the bloodstream and are easily accessible, making them potentially superior tissue sites for replacement hormone production or vaccination by gene transfer. Suggested methods for gene delivery include transcutaneous injection and retrograde infusion through salivary ducts. We demonstrate how to perform Retrograde Salivary Gland Infusion (RSGI) in non-human primates. We describe the important anatomic landmarks including identification of the parotid papilla, an atraumatic method of cannulating and sealing Stensen&#39;s Duct utilizing basic dental tools, polyethylene tubing, and cyanoacrylate, and the appropriate rate of infusion. While this is the least traumatic method of delivery, the method is still limited by the volume able to be delivered (&#60;0.5 mL) and the potential for trauma to the duct and gland. We demonstrate using fluoroscopy that an infusate can be fully delivered into the gland, and further demonstrate by immunohistochemistry the transduction of a typical vector and expression of the delivered gene.

Successful procedure, transduction and transcription 
Figure 1 shows the parotid papilla adjacent to the 2nd molar on the posterior superior cheek. The image also shows the correct placement of the mouth brace, one rubber end on the hard palate and the other rubber end on the ipsilateral canine. Figure 2 shows an image taken after successful cannulation of the parotid papilla at the 2 cm mark on the PET10. Fi...

Watch this Scientific Journal Video about Retrograde Parotid Gland Infusion through Stensen's Duct in a Non-Human Primate for Vectored Gene Delivery at JoVE.com

Retrograde Parotid Gland Infusion through Stensen&#039;s Duct in a Non-Human Primate for Vectored Gene Delivery

Salivary glands have been proposed as a tissue target site for gene therapy, especially in the area of vaccination by gene transfer. We demonstrate gene delivery in a non-human primate model utilizing retrograde parotid infusion.

Retrograde Parotid Gland Infusion through Stensen's Duct in a Non-Human Primate for Vectored Gene Delivery

Salivary glands are an attractive tissue target for gene therapy with promising results already leading to human trials. They are inherently capable of ...

This protocol is important because it demonstrates the procedure of retrograde salivary gland infusion in detail. The procedure can be used for a variety of medical reasons, such as vectored immunoprophylaxis or gene therapy. This technique is easy to learn and reproduce.The authors have managed to perform this procedure successfully on multiple occasions in spite of not being oral surgeons, nor having any such background. After anesthetizing use dental loupes for magnification and identify the parotid papilla or the opening of the Stenson's duct on the posterior cheek adjacent to the upper second molar. Gently dilate the parotid papilla by placing the point of a conical dilator into the center or opening of the papilla and rotate the dilator back and forth for approximately 20 to 30 seconds.Next, using tweezers hold the marked end of the polyethylene tube attached to the infusate containing syringe at approximately 0.5 centimeters from the distal end and gently insert the tip of the tube into the dilated papilla. Gently advance the tube by small rotating movements to help the tubes slide, followed by readjustment of the tweezers 0.5 centimeters proximal to the previous grip. Repeat this process until the two centimeter mark reaches the parotid papilla.Next, to seal the parotid papilla and reduce spillage of the infusate back in the oral cavity, apply a cyanoacrylate on the cheek around the papilla and on the inserted tube. Once the cyanoacrylate dries, slowly inject the infusate over five minutes at a rate of 100 microliters per minute. After the infusion is complete, leave the tube in place for at least five minutes, thereby keeping the duct sealed and allowing the infusate to remain in the parotid gland.Finally, remove the tube with gentle traction and the cyanoacrylate will pull free with the tube. Fluoroscopy using a radio contrast infusion demonstrated branching of the solution through the Stenson's duct and into the parotid gland. Immuno as the chemical analysis of the parotid gland revealed positive staining for EGFP in both the ductal and acinar cells indicating successful transduction and transcription in both cell types.The main challenge in this procedure is probably introducing the polyethylene tube into the papilla, which should be done very gently and slowly.

retrograde-parotid-gland-infusion-through-stensen-s-duct-non-human

Research

JoVE Journal

Immunology and Infection

Recognition of Epidermal Transglutaminase by IgA and Tissue Transglutaminase 2 Antibodies in a Rare Case of Rhesus Dermatitis

Tissue transglutaminase 2 (tTG2) is an intestinal digestive enzyme which deamidates already partially digested dietary gluten e.g. gliadin peptides. In genetically predisposed individuals, tTG2 triggers autoimmune responses that are characterized by the production of tTG2 antibodies and their direct deposition into small intestinal wall 1,2. The presence of such antibodies constitutes one of the major hallmarks of the celiac disease (CD). Epidermal transglutaminase (eTG) is another member of the transglutaminase family that can also function as an autoantigen in a small minority of CD patients. In these relatively rare cases, eTG triggers an autoimmune reaction (a skin rash) clinically known as dermatitis herpetiformis (DH). Although the exact mechanism of CD and DH pathogenesis is not well understood, it is known that tTG2 and eTG share antigenic epitopes that can be recognized by serum antibodies from both CD and DH patients 3,4.
In this study, the confocal microscopy examination of biopsy samples from skin lesions of two rhesus macaques (Macaca mulatta) with dermatitis (Table 1, Fig. 1 and 2) was used to study the affected tissues. In one animal (EM96) a spectral overlap of IgA and tTG2 antibodies (Fig. 3) was demonstrated. The presence of double-positive tTG2+IgA+ cells was focused in the deep epidermis, around the dermal papillae. This is consistent with lesions described in DH patients 3. When EM96 was placed on a gluten-free diet, the dermatitis, as well as tTG2+IgA+ deposits disappeared and were no longer detectable (Figs. 1-3). Dermatitis reappeared however, based on re-introduction of dietary gluten in EM96 (not shown). In other macaques including animal with unrelated dermatitis, the tTG2+IgA+ deposits were not detected. Gluten-free diet-dependent remission of dermatitis in EM96 together with presence of tTG2+IgA+ cells in its skin suggest an autoimmune, DH-like mechanism for the development of this condition. This is the first report of DH-like dermatitis in any non-human primate.

Recognition of Epidermal Transglutaminase by IgA and Tissue Transglutaminase 2 Antibodies in a Rare Case of Rhesus Dermatitis

Dermatitis herpetiformis (DH) is a chronic inflammatory condition characterized by an autoimmune reaction between IgA and epidermal transglutaminase (eTG). DH develops in a very small portion of gluten-sensitive and/or celiac patients. The results of this study indicate that DH can also develop in a rhesus monkey host with symptoms of idiopatic dermatitis.

Tissue transglutaminase 2 (tTG2) is an intestinal digestive enzyme which deamidates already partially digested dietary gluten e.g. gliadin peptides. In ...

Visualizing Dengue Virus through Alexa Fluor Labeling

The early events in the interaction between virus and cell can have profound influence on the outcome of infection. Determining the factors 
that influence this interaction could lead to improved understanding of disease pathogenesis and thus influence vaccine or therapeutic design. Hence, the development 
of methods to probe this interaction would be useful. Recent advancements in fluorophores development1-3 and imaging technology4 can be exploited to 
improve our current knowledge on dengue pathogenesis and thus pave the way to reduce the millions of dengue infections occurring annually.

The enveloped dengue virus has an external scaffold consisting of 90 envelope glycoprotein (E) dimers protecting the nucleocapsid shell, 
which contains a single positive strand RNA genome5. The identical protein subunits on the virus surface can thus be labeled with an amine reactive dye and visualized 
through immunofluorescent microscopy. Here, we present a simple method of labeling of dengue virus with Alexa Fluor succinimidyl ester dye dissolved directly in a sodium 
bicarbonate buffer that yielded highly viable virus after labeling. There is no standardized procedure for the labeling of live virus and existing manufacturer&#x2019;s protocol 
for protein labeling usually requires the reconstitution of dye in dimethyl sulfoxide. The presence of dimethyl sulfoxide, even in minute quantities, can block 
productive infection of virus and also induce cell cytotoxicity6. The exclusion of the use of dimethyl sulfoxide in this protocol thus reduced this possibility. 
Alexa Fluor dyes have superior photostability and are less pH-sensitive than the common dyes, such as fluorescein and rhodamine2, making them ideal for 
studies on cellular uptake and endosomal transport of the virus. The conjugation of Alexa Fluor dye did not affect the recognition of labeled dengue 
virus by virus-specific antibody and its putative receptors in host cells7. This method could have useful applications in virological studies.

Taking advantage of the advancements in fluorophore development and imaging technology, a simple method of Alexa Fluor labeling of dengue virus was devised to visualize the early interactions between virus and cell.

The early events in the interaction between virus and cell can have profound influence on the outcome of infection. Determining the factors 
that ...

Saliva, Salivary Gland, and Hemolymph Collection from Ixodes scapularis Ticks

Ticks are found worldwide and afflict humans with many tick-borne illnesses. Ticks are vectors for pathogens that cause Lyme disease and tick-borne relapsing fever (Borrelia spp.), Rocky Mountain Spotted fever (Rickettsia rickettsii), ehrlichiosis (Ehrlichia chaffeensis and E. equi), anaplasmosis (Anaplasma phagocytophilum), encephalitis (tick-borne encephalitis virus), babesiosis (Babesia spp.), Colorado tick fever (Coltivirus), and tularemia (Francisella tularensis) 1-8. To be properly transmitted into the host these infectious agents differentially regulate gene expression, interact with tick proteins, and migrate through the tick 3,9-13. For example, the Lyme disease agent, Borrelia burgdorferi, adapts through differential gene expression to the feast and famine stages of the tick's enzootic cycle 14,15. Furthermore, as an Ixodes tick consumes a bloodmeal Borrelia replicate and migrate from the midgut into the hemocoel, where they travel to the salivary glands and are transmitted into the host with the expelled saliva 9,16-19.
As a tick feeds the host typically responds with a strong hemostatic and innate immune response 11,13,20-22. Despite these host responses, I. scapularis can feed for several days because tick saliva contains proteins that are immunomodulatory, lytic agents, anticoagulants, and fibrinolysins to aid the tick feeding 3,11,20,21,23. The immunomodulatory activities possessed by tick saliva or salivary gland extract (SGE) facilitate transmission, proliferation, and dissemination of numerous tick-borne pathogens 3,20,24-27. To further understand how tick-borne infectious agents cause disease it is essential to dissect actively feeding ticks and collect tick saliva. This video protocol demonstrates dissection techniques for the collection of hemolymph and the removal of salivary glands from actively feeding I. scapularis nymphs after 48 and 72 hours post mouse placement. We also demonstrate saliva collection from an adult female I. scapularis tick.

Saliva, Salivary Gland, and Hemolymph Collection from Ixodes scapularis Ticks

The collection of infected tick hemolymph, salivary glands, and saliva is important to study how tick-borne pathogens cause disease. In this protocol we demonstrate how to collect hemolymph and salivary glands from feeding Ixodes scapularis nymphs. We also demonstrate saliva collection from female I. scapularis adults.

Ticks are found worldwide and afflict humans with many tick-borne illnesses. Ticks are vectors for pathogens that cause Lyme disease and tick-borne ...

Feeding of Ticks on Animals for Transmission and Xenodiagnosis in Lyme Disease Research

Transmission of the etiologic agent of Lyme disease, Borrelia burgdorferi, occurs by the attachment and blood feeding of Ixodes species ticks on mammalian hosts. In nature, this zoonotic bacterial pathogen may use a variety of reservoir hosts, but the white-footed mouse (Peromyscus leucopus) is the primary reservoir for larval and nymphal ticks in North America. Humans are incidental hosts most frequently infected with B. burgdorferi by the bite of ticks in the nymphal stage. B. burgdorferi adapts to its hosts throughout the enzootic cycle, so the ability to explore the functions of these spirochetes and their effects on mammalian hosts requires the use of tick feeding. In addition, the technique of xenodiagnosis (using the natural vector for detection and recovery of an infectious agent) has been useful in studies of cryptic infection. In order to obtain nymphal ticks that harbor B. burgdorferi, ticks are fed live spirochetes in culture through capillary tubes. Two animal models, mice and nonhuman primates, are most commonly used for Lyme disease studies involving tick feeding. We demonstrate the methods by which these ticks can be fed upon, and recovered from animals for either infection or xenodiagnosis.

Lyme disease is the most commonly-reported vector-borne disease in North America. The causative agent, Borrelia burgdorferi is a spirochete bacterium transmitted by Ixodid ticks. Transmission and detection of infection in animal models is optimized by the use of tick feeding, which we describe here.

Transmission of the etiologic agent of Lyme disease, Borrelia burgdorferi, occurs by the  attachment and blood feeding of Ixodes species ticks on ...

A Restriction Enzyme Based Cloning Method to Assess the In vitro Replication Capacity of HIV-1 Subtype C Gag-MJ4 Chimeric Viruses

The protective effect of many HLA class I alleles on HIV-1 pathogenesis and disease progression is, in part, attributed to their ability to target conserved portions of the HIV-1 genome that escape with difficulty. Sequence changes attributed to cellular immune pressure arise across the genome during infection, and if found within conserved regions of the genome such as Gag, can affect the ability of the virus to replicate in vitro. Transmission of HLA-linked polymorphisms in Gag to HLA-mismatched recipients has been associated with reduced set point viral loads. We hypothesized this may be due to a reduced replication capacity of the virus. Here we present a novel method for assessing the in vitro replication of HIV-1 as influenced by the gag gene isolated from acute time points from subtype C infected Zambians. This method uses restriction enzyme based cloning to insert the gag gene into a common subtype C HIV-1 proviral backbone, MJ4. This makes it more appropriate to the study of subtype C sequences than previous recombination based methods that have assessed the in vitro replication of chronically derived gag-pro sequences. Nevertheless, the protocol could be readily modified for studies of viruses from other subtypes. Moreover, this protocol details a robust and reproducible method for assessing the replication capacity of the Gag-MJ4 chimeric viruses on a CEM-based T cell line. This method was utilized for the study of Gag-MJ4 chimeric viruses derived from 149 subtype C acutely infected Zambians, and has allowed for the identification of residues in Gag that affect replication. More importantly, the implementation of this technique has facilitated a deeper understanding of how viral replication defines parameters of early HIV-1 pathogenesis such as set point viral load and longitudinal CD4+ T cell decline.

A Restriction Enzyme Based Cloning Method to Assess the In vitro Replication Capacity of HIV-1 Subtype C Gag-MJ4 Chimeric Viruses

HIV-1 pathogenesis is defined by both viral characteristics and host genetic factors. Here we describe a robust method that allows for reproducible measurements to assess the impact of the gag gene sequence variation on the in vitro replication capacity of the virus.

The protective effect of many HLA class I alleles on HIV-1 pathogenesis and disease progression is, in part, attributed to their ability to target ...

A Novel Microdissection Approach to Recovering Mycobacterium tuberculosis Specific Transcripts from Formalin Fixed Paraffin Embedded Lung Granulomas

Microdissection has been used for the examination of tissues at DNA, RNA, and protein levels for over a decade. Laser capture microscopy (LCM) is the most common microdissection technique used today. In this technique, a laser is used to focally melt a thermoplastic membrane that overlies a dehydrated tissue section1. The tissue section composite is then lifted and separated from the membrane. Although this technique can be used successfully for tissue examination, it is time consuming and expensive. Furthermore, the successful completion of procedures using this technique requires the use of a laser, thus limiting its use. A new more affordable and practical microdissection approach called mesodissection is a possible solution to the pitfalls of LCM. This technique employs the MESO-1/MeSectr system to mill the desired tissue from a slide mounted tissue sample while concurrently dispensing and aspirating fluid to recover the desired tissue sample into a consumable mill bit. Before the dissection process begins, the user aligns the formalin fixed paraffin embedded (FFPE) slide with a hematoxylin and eosin stained (H&#38;E) reference slide. Thereafter, the operator annotates the desired dissection area and proceeds to dissect the appropriate segment. The program generates an archived image of the dissection. The main advantage of mesodissection is the short duration needed to dissect a slide, taking an average of ten minutes from set up to sample generation in this experiment. Additionally, the system is significantly more cost effective and user friendly. A slight disadvantage is that it is not as precise as laser capture microscopy. In this article we demonstrate how mesodissection can be used to extract RNA from slides from FFPE granulomas caused by Mycobacterium tuberculosis (Mtb).

A Novel Microdissection Approach to Recovering Mycobacterium tuberculosis Specific Transcripts from Formalin Fixed Paraffin Embedded Lung Granulomas

Microdissection has been extensively employed for the examination of DNA, RNA, and protein within tissue. Laser capture microscopy (LCM) is the most commonly used method, but a new milling technique, mesodissection, is recently available. We demonstrate RNA extraction from mesodissected formalin fixed paraffin embedded tissue slides of Mycobacterium tuberculosis granulomas.

Microdissection has been used for the examination of tissues at DNA, RNA, and protein levels for over a decade. Laser capture microscopy (LCM) is the most ...

The Mesenteric Lymph Duct Cannulated Rat Model: Application to the Assessment of Intestinal Lymphatic Drug Transport

The intestinal lymphatic system plays key roles in fluid transport, lipid absorption and immune function. Lymph flows directly from the small intestine via a series of lymphatic vessels and nodes that converge at the superior mesenteric lymph duct. Cannulation of the mesenteric lymph duct thus enables the collection of mesenteric lymph flowing from the intestine. Mesenteric lymph consists of a cellular fraction of immune cells (99% lymphocytes), aqueous fraction (fluid, peptides and proteins such as cytokines and gut hormones) and lipoprotein fraction (lipids, lipophilic molecules and apo-proteins). The mesenteric lymph duct cannulation model can therefore be used to measure the concentration and rate of transport of a range of factors from the intestine via the lymphatic system. Changes to these factors in response to different challenges (e.g., diets, antigens, drugs) and in disease (e.g., inflammatory bowel disease, HIV, diabetes) can also be determined. An area of expanding interest is the role of lymphatic transport in the absorption of orally administered lipophilic drugs and prodrugs that associate with intestinal lipid absorption pathways. Here we describe, in detail, a mesenteric lymph duct cannulated rat model which enables evaluation of the rate and extent of lipid and drug transport via the lymphatic system for several hours following intestinal delivery. The method is easily adaptable to the measurement of other parameters in lymph. We provide detailed descriptions of the difficulties that may be encountered when establishing this complex surgical method, as well as representative data from failed and successful experiments to provide instruction on how to confirm experimental success and interpret the data obtained.

Here we describe a technique to cannulate the mesenteric lymph duct in rats which enables quantification of lipid and drug transport via the lymphatic system following intestinal delivery. The technique can be adapted to assess mesenteric lymph concentrations and/or transport of fluid, immune cells, peptides, proteins and lipophilic molecules.

The intestinal lymphatic system plays key roles in fluid transport, lipid absorption and immune function. Lymph flows directly from the small intestine ...

Utilizing the Antigen Capsid-Incorporation Strategy for the Development of Adenovirus Serotype 5-Vectored Vaccine Approaches

Adenovirus serotype 5 (Ad5) has been extensively modified with traditional transgene methods for the vaccine development. The reduced efficacies of these traditionally modified Ad5 vectors in clinical trials could be primarily correlated with Ad5 pre-existing immunity (PEI) among the majority of the population. To promote Ad5-vectored vaccine development by solving the concern of Ad5 PEI, the innovative Antigen Capsid-Incorporation strategy has been employed. By merit of this strategy, Ad5-vectored we first constructed the hexon shuttle plasmid HVR1-KWAS-HVR5-His6/pH5S by subcloning the hypervariable region (HVR) 1 of hexon into a previously constructed shuttle plasmid HVR5-His6/pH5S, which had His6 tag incorporated into the HVR5. This HVR1 DNA fragment containing a HIV epitope ELDKWAS was synthesized. HVR1-KWAS-HVR5-His6/pH5S was then linearized and co-transformed with linearized backbone plasmid pAd5/&#8710;H5 (GL) , for homologous recombination. This recombined plasmid pAd5/H5-HVR1-KWAS-HVR5-His6 was transfected into cells to generate the viral vector Ad5/H5-HVR1-KWAS-HVR5-His6. This vector was validated to have qualitative fitness indicated by viral physical titer (VP/ml), infectious titer (IP/ml) and corresponding VP/IP ratio. Both the HIV epitope and His6 tag were surface-exposed on the Ad5 capsid, and retained epitope-specific antigenicity of their own. A neutralization assay indicated the ability of this divalent vector to circumvent neutralization by Ad5-positive sera in vitro. Mice immunization demonstrated the generation of robust humoral immunity specific to the HIV epitope and His6. This proof-of-principle study suggested that the protocol associated with the Antigen Capsid-Incorporation strategy could be feasibly utilized for the generation of Ad5-vectored vaccines by modifying different capsid proteins. This protocol could even be further modified for the generation of rare-serotype adenovirus-vectored vaccines.

Here, we present a protocol to generate a proof-of-principle divalent adenovirus type 5 (Ad5) vector Ad5/H5-HVR1-KWAS-HVR5-His6 by utilizing the Antigen Capsid-Incorporation strategy. This vector was demonstrated to exhibit qualitative fitness, the capability to escape Ad5-positive sera in vitro, and the antigenicity as well as immunogenicity to the incorporated antigens.

Adenovirus serotype 5 (Ad5) has been extensively modified with traditional transgene methods for the vaccine development. The reduced efficacies of these ...

A Simple and Efficient Approach to Construct Mutant Vaccinia Virus Vectors

The CRISPR-associated endonuclease Cas9 can edit particular genomic loci directed by a single guide RNA (gRNA). The CRISPR/Cas9 system has been successfully employed for editing genomes of various organisms. Here we describe a protocol for editing the vaccinia virus (VV) genome in the cytoplasm of VV-infected CV-1 cells using the RNA-guided Cas9. RNA-guided Cas9 induces double-stranded DNA breaks facilitating homologous recombination efficiently and specifically in the targeted site of VV and a transgene can be incorporated into these sites by homologous recombination. By using a site-specific homologous vector with transgene(s), a N1L gene-deleted VV with the red fluorescence protein (RFP) gene incorporated in this region was generated with a successful recombination efficiency 10 times greater than that obtained from the conventional homologous recombination method. This protocol demonstrates successful use of RNA-guided Cas9 system to generate mutant VVs with enhanced efficiency.

Vaccinia virus (VV) has been widely used in biomedical research and the improvement of human health. This article describes a simple, highly efficient method to edit the VV genome using a CRISPR-Cas9 system.

The CRISPR-associated endonuclease Cas9 can edit particular genomic loci directed by a single guide RNA (gRNA). The CRISPR/Cas9 system has been ...

Analysis of 18FDG PET/CT Imaging as a Tool for Studying Mycobacterium tuberculosis Infection and Treatment in Non-human Primates

Mycobacterium tuberculosis remains the number one infectious agent in the world today. With the emergence of antibiotic resistant strains, new clinically relevant methods are needed that evaluate the disease process and screen for potential antibiotic and vaccine treatments. Positron Emission Tomography/Computed Tomography (PET/CT) has been established as a valuable tool for studying a number of afflictions such as cancer, Alzheimer&#39;s disease, and inflammation/infection. Outlined here are a number of strategies that have been employed to evaluate PET/CT images in cynomolgus macaques that are infected intrabronchially with low doses of M. tuberculosis. Through evaluation of lesion size on CT and uptake of 18F-fluorodeoxyglucose (FDG) in lesions and lymph nodes in PET images, these described methods show that PET/CT imaging can predict future development of active versus latent disease and the propensity for reactivation from a latent state of infection. Additionally, by analyzing the overall level of lung inflammation, these methods determine antibiotic efficacy of drugs against M. tuberculosis in the most clinically relevant existing animal model. These image analysis methods are some of the most powerful tools in the arsenal against this disease as not only can they evaluate a number of characteristics of infection and drug treatment, but they are also directly translatable to a clinical setting for use in human studies.

Analysis of 18FDG PET/CT Imaging as a Tool for Studying Mycobacterium tuberculosis Infection and Treatment in Non-human Primates

Here, we present a protocol to describe the analysis of 18F-FDG PET/CT imaging in non-human primates that have been infected with M. tuberculosis to study disease process, drug treatment, and disease reactivation.

Mycobacterium tuberculosis remains the number one infectious agent in the world today. With the emergence of antibiotic resistant strains, new clinically ...