Name: the &alpha;-test: rapid cell-free cd4 enumeration using whole saliva
Uploaded: 2012-05-16T13:00:00
Description: Watch this Scientific Journal Video about The Î±-test: Rapid Cell-free CD4 Enumeration Using Whole Saliva at JoVE.com

Research was supported by the Harry Winston Research Foundation.

1. Prepare Fresh Working Solutions
<ol>
	<li>TBS: 0.05 M Tris Buffered Saline, pH 7.8 (TBS). Prepare 60 ml TBS/microplate.</li>
	<li>PPE: Porcine pancreatic elastase, type 1 (PPE) is provided as a suspension. Shake well and dilute PPE in TBS to approximately 0.01 U/ml. Prepare 6 ml working solution/microplate).</li>
	<li>SA3NA: Succinyl-L-Ala-L-Ala-L-Ala-p-nitroanilide (SA3NA). Prepare 0.1 M stock SA3NA solution in dimethyl sulfoxide (D...

<ol>
	<li>Friedlander, Y., Kark, J. D., Eisenberg, S., Stein, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calculation+of+LDL-cholesterol+from+total+cholesterol,+triglyceride+and+HDL-cholesterol:+a+comparison+of+methods+in+the+Jerusalem+Lipid+Research+Clinic+Prevalence+Study.">Calculation of LDL-cholesterol from total cholesterol, triglyceride and HDL-cholesterol: a comparison of methods in the Jerusalem Lipid Research Clinic Prevalence Study.</a> Isr. J. Med. Sci. 18, 1242-1252 (1982).</li><li>Lapidot, T., Petit, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+understanding+of+stem+cell+mobilization:+The+roles+of+chemokines,+proteolytic+enzymes,+adhesion+molecules,+cytokines,+and+stromal+cells.">Current understanding of stem cell mobilization: The roles of chemokines, proteolytic enzymes, adhesion molecules, cytokines, and stromal cells.</a> Exp. Hematol. 30, 973-981 (2002).</li><li>Bristow, C. L., Alfano, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=&#945;1Antitrypsin+therapy+increases+CD4++lymphocytes+to+normal+values+in+HIV-1+patients.">&#945;1Antitrypsin therapy increases CD4+ lymphocytes to normal values in HIV-1 patients.</a> Soluble factors mediating innate immune responses to HIV infection. , (2010).</li><li>Bristow, C. L., Patel, H., Arnold, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self+antigen+prognostic+for+human+immunodeficiency+virus+disease+progression.">Self antigen prognostic for human immunodeficiency virus disease progression.</a> Clin. Diagn. Lab. Immunol. 8, 937-942 (2001).</li><li>Bristow, C. L., Babayeva, M. A., LaBrunda, M., Mullen, M. P., Winston, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=&#945;1Proteinase+Inhibitor+regulates+CD4++lymphocyte+levels+and+is+rate+limiting+in+HIV-1+disease.">&#945;1Proteinase Inhibitor regulates CD4+ lymphocyte levels and is rate limiting in HIV-1 disease.</a> PLoS One. , (2011).</li><li>de Almeida, P. D. V., Gregio, A. M. T., Machado, M. A. N., de Lima, A. A. S., Azevedo, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Saliva+Composition+and+Functions:+A+Comprehensive+Review.">Saliva Composition and Functions: A Comprehensive Review.</a> J. Contemp. Dent. Pract. 9, 72-80 (2008).</li><li>Edgar, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Saliva:+its+secretion,+composition+and+funcitons.">Saliva: its secretion, composition and funcitons.</a> Br. Dent. J. , 172-305 (1992).</li><li>Bristow, C. L., Meo, F. d. i., Arnold, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specific+activity+of+&#945;1proteinase+inhibitor+and+++2macroglobulin+in+human+serum:+Application+to+insulin-dependent+diabetes+mellitus.">Specific activity of &#945;1proteinase inhibitor and 2macroglobulin in human serum: Application to insulin-dependent diabetes mellitus.</a> Clin. Immunol. Immunopathol. 89, 247-259 (1998).</li><li>Pederson, E. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salivary+levels+of+&#945;2-macroglobulin,+&#945;1-antitrypsin,+C-reactive+protein,+cathepsin+G+and+elastase+in+humans+with+or+without+destructive+periodontal+disease.">Salivary levels of &#945;2-macroglobulin, &#945;1-antitrypsin, C-reactive protein, cathepsin G and elastase in humans with or without destructive periodontal disease.</a> Arch. Oral Biol. 40, 1151-1155 (1995).</li><li>Shak, S., Capon, D. J., Hellmiss, R., Marsters, S. A., Baker, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recombinant+human+DNase+I+reduces+the+viscosity+of+cystic+fibrosis+sputum.">Recombinant human DNase I reduces the viscosity of cystic fibrosis sputum.</a> PNAS. 87, 9188-9192 (1990).</li><li>LeVeque, F. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+multicenter,+randomized,+double-blind,+placebo-controlled,+dose-+titration+study+of+oral+pilocarpine+for+treatment+of+radiation-induced+xerostomia+in+head+and+neck+cancer+patients.">A multicenter, randomized, double-blind, placebo-controlled, dose- titration study of oral pilocarpine for treatment of radiation-induced xerostomia in head and neck cancer patients.</a> J. Clin. Oncol. 11, 1124-1131 (1993).</li><li>Stevens, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluating+new+CD4+enumeration+technologies+for+resource-constrained+countries.">Evaluating new CD4 enumeration technologies for resource-constrained countries.</a> Nat. Rev. Microbiol. 6, S29-S38 (2008).</li><li>WHO. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> 2010 ART guidelines for adults and adolescents - evidence map. , (2010).</li></ol>

Undiluted serum contains median 36 &mu;M &alpha;1PI and 3.6 &mu;M &alpha;2macroglobulin (&alpha;2M) a 10-fold difference 8. Both proteins compete for binding to PPE. These two characteristics, concentration and PPE affinity, have been exploited to develop a method that is capable of specifically measuring &alpha;1PI in normal serum in the presence of competing &alpha;2M 8. This method can detect as little as 50 nM &mu;1PI in 0.3% ser...

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 </tr>
 <tr>
 <td>Sialogogue, 0.05M citric acid</td>
 <td>Eda's Sugarfree Candies, 4900 Rear N.20th Street, Philadelphia, PA 19144</td>
 <td>Sugar-Free Lemon dropS </td>
 </tr>
 <tr>
 <td>Porcine pancreatic elastase, type 1 (EC 3.4.21.36)</td>
 <td>Sigma-Aldrich, St. Louis, MO 63103</td>
 <td>E1250</td>
 </tr>
 <tr>
 <td>Succinyl-L-Ala-L-Ala-L-Ala-p-nitroanilide</td>
 <td>Sigma-Aldrich</td>
 <td>S4760 </td>
 </tr>
 <tr>
 <td>Coomassie Brilliant Blue R-250</td>
 <td>Sigma-Aldrich</td>
 <td>B7920</td>
 </tr>
 <tr>
 <td>Tissue culture-treated, 96 well microplates</td>
 <td>Becton Dickinson, Franklin Lakes, NJ 07417-1886</td>
 <td>35-3072</td>
 </tr>
 <tr>
 <td>Microplate Reader with filters for 405 nm and 595 nm</td>
 <td>MTX Lab Systems, 8456 Tyco Road, Building D, Vienna, Virginia 22182</td>
 <td>Dynex P97277</td>
 </tr>
 </tbody>
</table>

the &alpha;-test: rapid cell-free cd4 enumeration using whole saliva

There is an urgent need for affordable CD4 enumeration to monitor HIV disease. CD4 enumeration is out of reach in resource-limited regions due to the time and temperature restrictions, technical sophistication, and cost of reagents, in particular monoclonal antibodies to measure CD4 on blood cells, the only currently acceptable method. A commonly used cost-saving and time-saving laboratory strategy is to calculate, rather than measure certain blood values. For example, LDL levels are calculated using the measured levels of total cholesterol, HDL, and triglycerides1. Thus, identification of cell-free correlates that directly regulate the number of CD4+ T cells could provide an accurate method for calculating CD4 counts due to the physiological relevance of the correlates.
The number of stem cells that enter blood and are destined to become circulating CD4+ T cells is determined by the chemokine CXCL12 and its receptor CXCR4 due to their influence on locomotion2. The process of stem cell locomotion into blood is additionally regulated by cell surface human leukocyte elastase (HLECS) and the HLECS-reactive active &alpha;1proteinase inhibitor (&alpha;1PI, &alpha;1antitrypsin, SerpinA1)3. In HIV-1 disease, &alpha;1PI is inactivated due to disease processes 4. In the early asymptomatic categories of HIV-1 disease, active &alpha;1PI was found to be below normal in 100% of untreated HIV-1 patients (median=12 &mu;M, and to achieve normal levels during the symptomatic categories4, 5. This pattern has been attributed to immune inactivation, not to insufficient synthesis, proteolytic inactivation, or oxygenation. We observed that in HIV-1 subjects with &gt;220 CD4 cells/&mu;l, CD4 counts were correlated with serum levels of active &alpha;1PI (r2=0.93, p&lt;0.0001, n=26) and inactive &alpha;1PI (r2=0.91, p&lt;0.0001, n=26) 5. Administration of &alpha;1PI to HIV-1 infected and uninfected subjects resulted in dramatic increases in CD4 counts suggesting &alpha;1PI participates in regulating the number of CD4+ T cells in blood 3.
With stimulation, whole saliva contains sufficient serous exudate (plasma containing proteinaceous material that passes through blood vessel walls into saliva) to allow measurement of active &alpha;1PI and the correlation of this measurement is evidence that it is an accurate method for calculating CD4 counts. Briefly, sialogogues such as chewing gum or citric acid stimulate the exudation of serum into whole mouth saliva. After stimulating serum exudation, the activity of serum &alpha;1PI in saliva is measured by its capacity to inhibit elastase activity. Porcine pancreatic elastase (PPE) is a readily available inexpensive source of elastase. PPE binds to &alpha;1PI forming a one-to-one complex that prevents PPE from cleaving its specific substrates, one of which is the colorimetric peptide, succinyl-L-Ala-L-Ala-L-Ala-p-nitroanilide (SA3NA). Incubating saliva with a saturating concentration of PPE for 10 min at room temperature allows the binding of PPE to all the active &alpha;1PI in saliva. The resulting inhibition of PPE by active &alpha;1PI can be measured by adding the PPE substrate SA3NA. (Figure 1). Although CD4 counts are measured in terms of blood volume (CD4 cells/&mu;l), the concentration of &alpha;1PI in saliva is related to the concentration of serum in saliva, not to volume of saliva since volume can vary considerably during the day and person to person6. However, virtually all the protein in saliva is due to serum content, and the protein content of saliva is measurable7. Thus, active &alpha;1PI in saliva is calculated as a ratio to saliva protein content and is termed the &alpha;1PI Index. Results presented herein demonstrate that the &alpha;1PI Index provides an accurate and precise physiologic method for calculating CD4 counts.

Watch this Scientific Journal Video about The Î±-test: Rapid Cell-free CD4 Enumeration Using Whole Saliva at JoVE.com

The &#945;-test: Rapid Cell-free CD4 Enumeration Using Whole Saliva

A CD4 enumeration method, the &#x03B1;-test, is described which uses whole saliva to provide rapid and accurate CD4 counts. The &alpha;-test costs pennies and eliminates the need for technical training, costly reagents such as monoclonal antibodies, instrumentation, refrigeration, transport of samples, as well as collection and handling of blood.

The &alpha;-test: Rapid Cell-free CD4 Enumeration Using Whole Saliva

There is an urgent need for affordable CD4 enumeration to monitor HIV disease. CD4 enumeration is out of reach in resource-limited regions due to the time ...

Research

JoVE Journal

Medicine

Accurate and Simple Measurement of the Pro-inflammatory Cytokine IL-1&beta; using a Whole Blood Stimulation Assay

Accurate and Simple Measurement of the Pro-inflammatory Cytokine IL-1&#946; using a Whole Blood Stimulation Assay

Inflammatory processes resulting from the secretion of soluble mediators by immune cells, lead to various manifestations in skin, joints and other tissues ...

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood

There is the need for a clinical assay to determine the extent to which a patient's blood is effectively anticoagulated by the ...

Sampling Human Indigenous Saliva Peptidome Using a Lollipop-Like Ultrafiltration Probe: Simplify and Enhance Peptide Detection for Clinical Mass Spectrometry

Although human saliva proteome and peptidome have been revealed 1-2 they were majorly identified from tryptic digests of saliva proteins. Identification ...

Collection and Extraction of Saliva DNA for Next Generation Sequencing

The preferred source of DNA in human genetics research is blood, or cell lines derived from blood, as these sources yield large quantities of high quality ...

Rapid Fractionation and Isolation of Whole Blood Components in Samples Obtained from a Community-based Setting

Collection and processing of whole blood samples in a non-clinical setting offers a unique opportunity to evaluate community-dwelling individuals both ...

Assessment of the Anticoagulant and Anti-inflammatory Properties of Endothelial Cells Using 3D Cell Culture and Non-anticoagulated Whole Blood

In vivo, endothelial cells are crucial for the natural anticoagulation of circulating blood. Consequently, endothelial cell activation leads to blood ...

Estimation of Nephron Number in Whole Kidney using the Acid Maceration Method

Nephron endowment refers to the total number of nephrons an individual is born with, as nephrogenesis in humans is completed by 36 weeks of gestation and ...

Rapid Evaluation of Toxicity of Chemical Compounds Using Zebrafish Embryos

The zebrafish is a widely used vertebrate model organism for the disease and phenotype-based drug discovery. The zebrafish generates many offspring, has ...