Name: antigenic liposomes for generation of disease-specific antibodies
Uploaded: 2018-10-25T13:00:00
Description: Watch this Scientific Journal Video about Antigenic Liposomes for Generation of Disease-specific Antibodies at JoVE.com

This research was supported by grants from the Department of Defense (W81XWH-16-1-0302 and W81XWH-16-1-0303).

The general method of coupling protein to lipid and incorporating into liposomes is based largely on earlier work15. All animal procedures described below have been approved by the University of North Carolina at Chapel Hill Institutional Animal Care and Use Committee (IACUC). All mice used in the peanut allergy model are BALB/cJ females purchased from at 3 weeks of age. The University of Alberta Animal Care and Use Committee (ACUC) has approved experiments involving use of mouse spleens for e...

<ol>
	<li>Gupta, R. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+prevalence,+severity,+and+distribution+of+childhood+food+allergy+in+the+United+States.">The prevalence, severity, and distribution of childhood food allergy in the United States.</a> Pediatrics. 128 (1), e9-e17 (2011).</li><li>Sicherer, S. H., Munoz-Furlong, A., Godbold, J. H., Sampson, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=US+prevalence+of+self-reported+peanut,+tree+nut,+and+sesame+allergy:+11-year+follow-up.">US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up.</a> Journal of Allergy and Clinical Immunology. 125 (6), 1322-1326 (2010).</li><li>Kim, E. H., 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=Sublingual+immunotherapy+for+peanut+allergy:+clinical+and+immunologic+evidence+of+desensitization.">Sublingual immunotherapy for peanut allergy: clinical and immunologic evidence of desensitization.</a> Journal of Allergy Clinical Immunology. 127 (3), 640-646 (2011).</li><li>Vickery, B. 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=Sustained+unresponsiveness+to+peanut+in+subjects+who+have+completed+peanut+oral+immunotherapy.">Sustained unresponsiveness to peanut in subjects who have completed peanut oral immunotherapy.</a> Journal of Allergy and Clinical Immunology. 133 (2), 468 (2014).</li><li>Jones, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epicutaneous+immunotherapy+for+the+treatment+of+peanut+allergy+in+children+and+young+adults.">Epicutaneous immunotherapy for the treatment of peanut allergy in children and young adults.</a> Journal of Allergy and Clinical Immunology. 139 (4), 1242 (2017).</li><li>Varshney, 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=A+randomized+controlled+study+of+peanut+oral+immunotherapy:+clinical+desensitization+and+modulation+of+the+allergic+response.">A randomized controlled study of peanut oral immunotherapy: clinical desensitization and modulation of the allergic response.</a> Journal of Allergy Clinical Immunology. 127 (3), 654-660 (2011).</li><li>Anagnostou, K., 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=Assessing+the+efficacy+of+oral+immunotherapy+for+the+desensitisation+of+peanut+allergy+in+children+(STOP+II):+a+phase+2+randomised+controlled+trial.">Assessing the efficacy of oral immunotherapy for the desensitisation of peanut allergy in children (STOP II): a phase 2 randomised controlled trial.</a> Lancet. 383 (9925), 1297-1304 (2014).</li><li>Sampson, H. 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=Effect+of+Varying+Doses+of+Epicutaneous+Immunotherapy+vs+Placebo+on+Reaction+to+Peanut+Protein+Exposure+Among+Patients+With+Peanut+Sensitivity:+A+Randomized+Clinical+Trial.">Effect of Varying Doses of Epicutaneous Immunotherapy vs Placebo on Reaction to Peanut Protein Exposure Among Patients With Peanut Sensitivity: A Randomized Clinical Trial.</a> The Journal of the American Medical Association. 318 (18), 1798-1809 (2017).</li><li>Bednar, K. 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=Human+CD22+Inhibits+Murine+B+Cell+Receptor+Activation+in+a+Human+CD22+Transgenic+Mouse+Model.">Human CD22 Inhibits Murine B Cell Receptor Activation in a Human CD22 Transgenic Mouse Model.</a> Journal Immunology. 199 (9), 3116-3128 (2017).</li><li>Macauley, M. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antigenic+liposomes+displaying+CD22+ligands+induce+antigen-specific+B+cell+apoptosis.">Antigenic liposomes displaying CD22 ligands induce antigen-specific B cell apoptosis.</a> Journal Clinical Investigation. 123 (7), 3074-3083 (2013).</li><li>Orgel, K. 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=Exploiting+CD22+on+antigen-specific+B+cells+to+prevent+allergy+to+the+major+peanut+allergen+Ara+h+2.">Exploiting CD22 on antigen-specific B cells to prevent allergy to the major peanut allergen Ara h 2.</a> Journal Allergy Clinical Immunology. 139 (1), 366-369 (2017).</li><li>Smarr, C. B., Hsu, C. L., Byrne, A. J., Miller, S. D., Bryce, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antigen-fixed+leukocytes+tolerize+Th2+responses+in+mouse+models+of+allergy.">Antigen-fixed leukocytes tolerize Th2 responses in mouse models of allergy.</a> Journal of Immunology. 187 (10), 5090-5098 (2011).</li><li>Kulis, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+2S+albumin+allergens+of+Arachis+hypogaea,+Ara+h+2+and+Ara+h+6,+are+the+major+elicitors+of+anaphylaxis+and+can+effectively+desensitize+peanut-allergic+mice.">The 2S albumin allergens of Arachis hypogaea, Ara h 2 and Ara h 6, are the major elicitors of anaphylaxis and can effectively desensitize peanut-allergic mice.</a> Clinical and Experimental Allergy. 42 (2), 326-336 (2012).</li><li>Dang, T. D., 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=Increasing+the+accuracy+of+peanut+allergy+diagnosis+by+using+Ara+h+2.">Increasing the accuracy of peanut allergy diagnosis by using Ara h 2.</a> Journal of Allergy Clinical Immunology. 129 (4), 1056-1063 (2012).</li><li>Loughrey, H. C., Choi, L. S., Cullis, P. R., Bally, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+procedures+for+the+coupling+of+proteins+to+liposomes.">Optimized procedures for the coupling of proteins to liposomes.</a> Journal Immunological Methods. 132 (1), 25-35 (1990).</li><li>Sen, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+structure+plays+a+critical+role+in+peanut+allergen+stability+and+may+determine+immunodominant+IgE-binding+epitopes.">Protein structure plays a critical role in peanut allergen stability and may determine immunodominant IgE-binding epitopes.</a> Journal of Immunology. 169 (2), 882-887 (2002).</li><li>Krall, N., da Cruz, F. P., Boutureira, O., Bernardes, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Site-selective+protein-modification+chemistry+for+basic+biology+and+drug+development.">Site-selective protein-modification chemistry for basic biology and drug development.</a> Nature Chemistry. 8 (2), 103-113 (2016).</li><li>Jimenez-Saiz, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lifelong+memory+responses+perpetuate+humoral+TH2+immunity+and+anaphylaxis+in+food+allergy.">Lifelong memory responses perpetuate humoral TH2 immunity and anaphylaxis in food allergy.</a> Journal Allergy and Clinical Immunology. 140 (6), 1604-1615 (2017).</li><li>Moutsoglou, D. M., Dreskin, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prolonged+Treatment+of+Peanut-Allergic+Mice+with+Bortezomib+Significantly+Reduces+Serum+Anti-Peanut+IgE+but+Does+Not+Affect+Allergic+Symptoms.">Prolonged Treatment of Peanut-Allergic Mice with Bortezomib Significantly Reduces Serum Anti-Peanut IgE but Does Not Affect Allergic Symptoms.</a> International Archives of Allergy and Immunology. 170 (4), 257-261 (2016).</li><li>LaMothe, R. 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=Tolerogenic+Nanoparticles+Induce+Antigen-Specific+Regulatory+T+Cells+and+Provide+Therapeutic+Efficacy+and+Transferrable+Tolerance+against+Experimental+Autoimmune+Encephalomyelitis.">Tolerogenic Nanoparticles Induce Antigen-Specific Regulatory T Cells and Provide Therapeutic Efficacy and Transferrable Tolerance against Experimental Autoimmune Encephalomyelitis.</a> Frontiers in Immunology. 9, 281 (2018).</li><li>Srivastava, K. D., 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=Investigation+of+peanut+oral+immunotherapy+with+CpG/peanut+nanoparticles+in+a+murine+model+of+peanut+allergy.">Investigation of peanut oral immunotherapy with CpG/peanut nanoparticles in a murine model of peanut allergy.</a> J Allergy Clin Immunol. 138 (2), 536-543 (2016).</li><li>Bellinghausen, I., Saloga, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+allergic+immune+responses+in+humanized+mice.">Analysis of allergic immune responses in humanized mice.</a> Cellular Immunology. 308, 7-12 (2016).</li><li>Pillai, S., Mattoo, H., Cariappa, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=B+cells+and+autoimmunity.">B cells and autoimmunity.</a> Curr Opin Immunol. 23 (6), 721-731 (2011).</li><li>Mantegazza, R., Cordiglieri, C., Consonni, A., Baggi, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+myasthenia+gravis:+utility+and+limitations.">Animal models of myasthenia gravis: utility and limitations.</a> International Journal of General Medicine. 9, 53-64 (2016).</li><li>Berman, P. 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The methods outlined here are a general protocol for the conjugation of a protein to a lipid which enables the display of the protein on liposomal nanoparticles. For very large multi-subunit proteins, this protocol may have limited utility. The ideal method would be the introduction of a site-specific tag that enables a biorthogonal chemical linking strategy to be used. If expressing the protein recombinantly, this can be possible using available site-specific strategies17, and a wide array of fun...

Food allergy affects 8% of children in the United States, and has increased in prevalence over the past decade1. Allergy to peanut affects 1% of children and is not typically outgrown2. Although several promising clinical trials are underway for the treatment of food allergy, including oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT), there are currently no FDA-approved treatment strategies for desensitizing peanut-allergic individuals3,4,5,6,7,8. Therefore, allergic individuals must strictly avoid allergens to avoid anaphylaxis. Many questions remain regarding routes of sensitization and underlying mechanisms of food allergy development.
Mouse models are a valuable tool for studying the mechanisms of allergy as well as developing new tolerogenic and desensitization therapies9,10,11,12. This is particularly true because the major peanut allergen (Ara h 2; Ah2) in humans is also the dominant allergen in several described mouse models13,14. While mouse models of peanut allergy are invaluable in studying mechanisms of sensitization and tolerance, a drawback is that they can be variable and require the use of adjuvants. More potent immunogens would be one way to minimize the intrinsic variability of such models. Since B-cells are strongly activated by multivalent antigens, antigenic liposomes displaying the allergen are a good option because of their ability to potentially activate B-cells through the B-cell receptor (BCR) while also having the property of efficiently priming the T-cell compartment through being taken up non-specifically by antigen-presenting cells.
Here, we describe a detailed protocol for conjugating protein antigens to liposomal nanoparticles using a facile and modular strategy. Using a surrogate antigen, anti-IgM Fab fragment, we demonstrate how potent such antigenic liposomes can be in stimulating B-cell activation. Antigenic liposomes displaying Ah2 antigen were used to develop a new mouse model of conferred sensitivity. In this model, splenocytes from verified peanut allergic mice, containing peanut-specific memory B- and T-cells, are transferred into na&#239;ve congenic mice. Memory antibody responses are induced by injection of liposomes conjugated with Ah2 into the recipient mice, in order to induce antibodies against Ah2. Followed by only one boost with soluble Ah2, Ah2-specific antibodies give rise to a strong anaphylactic response when these mice are subsequently challenged with Ah2. As mice undergoing the allergic reaction respond in a highly uniform manner and have not received an adjuvant, this approach is a desirable peanut allergy model and the outcomes suggest that it may have utility in other mouse models driven by antigens directed at allergens and possibly autoantigens.

<table>
	<tbody>
		<tr>
			<td>Model 2110 Fraction Collector</td>
			<td>BioRad</td>
			<td>7318122</td>
			<td></td>
		</tr>
		<tr>
			<td>Cholestrol</td>
			<td>Sigma</td>
			<td>C8667</td>
			<td>Sigma grade 99%</td>
		</tr>
		<tr>
			<td>SPDP</td>
			<td>Thermo Fisher Scientific</td>
			<td>21857</td>
			<td></td>
		</tr>
		<tr>
			<td>DSPC</td>
			<td>Avanti</td>
			<td>850365</td>
			<td></td>
		</tr>
		<tr>
			<td>DSPE-PEG 18:0</td>
			<td>Avanti</td>
			<td>880120</td>
			<td></td>
		</tr>
		<tr>
			<td>DSPE-PEG Maleimide</td>
			<td>Avanti</td>
			<td>880126</td>
			<td></td>
		</tr>
		<tr>
			<td>Extruder</td>
			<td>Avanti</td>
			<td>610000</td>
			<td>1mL syringe with holder/heating block</td>
		</tr>
		<tr>
			<td>Filters 0.1 &#181;m</td>
			<td>Avanti</td>
			<td>610005</td>
			<td></td>
		</tr>
		<tr>
			<td>Filters 0.8 &#181;m</td>
			<td>Avanti</td>
			<td>610009</td>
			<td></td>
		</tr>
		<tr>
			<td>10mm Filter Supports</td>
			<td>Avanti</td>
			<td>6100014</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass Round Bottom Flask</td>
			<td>Sigma</td>
			<td>Z100633</td>
			<td></td>
		</tr>
		<tr>
			<td>Turnover stoppers</td>
			<td>Thermo Fisher Scientific</td>
			<td>P-301398</td>
			<td></td>
		</tr>
		<tr>
			<td>Tubing</td>
			<td>Thermo Fisher Scientific</td>
			<td>P-198194</td>
			<td></td>
		</tr>
		<tr>
			<td>Leur Lock</td>
			<td>Thermo Fisher Scientific</td>
			<td>k4201634503</td>
			<td></td>
		</tr>
		<tr>
			<td>Sephadex G50 Beads</td>
			<td>GE Life Sciences</td>
			<td>17004201</td>
			<td></td>
		</tr>
		<tr>
			<td>Sephadex G100 Beads</td>
			<td>GE Life Sciences</td>
			<td>17006001</td>
			<td></td>
		</tr>
		<tr>
			<td>Heat Inactivated Fetal Calf Serum</td>
			<td>Thermo Fisher Scientific</td>
			<td>10082147</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES (1M)</td>
			<td>Thermo Fisher Scientific</td>
			<td>15630080</td>
			<td></td>
		</tr>
		<tr>
			<td>EGTA</td>
			<td>Sigma</td>
			<td>E3889</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin (10,000 U/mL)</td>
			<td>Thermo Fisher Scientific</td>
			<td>15140122</td>
			<td></td>
		</tr>
		<tr>
			<td>1x RBC lysis Buffer</td>
			<td>Thermo Fisher Scientific</td>
			<td>00-4333-57</td>
			<td></td>
		</tr>
		<tr>
			<td>Indo-1</td>
			<td>Invitrogen</td>
			<td>I1203</td>
			<td></td>
		</tr>
		<tr>
			<td>CD5-PE</td>
			<td>BioLegend</td>
			<td>100608</td>
			<td></td>
		</tr>
		<tr>
			<td>B220-PE-Cy7</td>
			<td>BioLegend</td>
			<td>103222</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS</td>
			<td>Thermo Fisher Scientific</td>
			<td>14170112</td>
			<td>without calcium and magnesium</td>
		</tr>
		<tr>
			<td>MgCl2</td>
			<td>Sigma</td>
			<td>M8266</td>
			<td></td>
		</tr>
		<tr>
			<td>CaCl2</td>
			<td>Sigma</td>
			<td>C4901</td>
			<td></td>
		</tr>
		<tr>
			<td>Fab anti-mouse IgM</td>
			<td>Jackson ImmunoResearch</td>
			<td>115-007-020</td>
			<td></td>
		</tr>
		<tr>
			<td>F(ab&#39;)2 anti-mouse IgM</td>
			<td>Jackson ImmunoResearch</td>
			<td>115-006-020</td>
			<td></td>
		</tr>
		<tr>
			<td>Peanut flour</td>
			<td>Golden Peanut Co.</td>
			<td>521271</td>
			<td>12% fat light roast, 50% protein</td>
		</tr>
		<tr>
			<td>Animal feeding needles</td>
			<td>Cadence Science</td>
			<td>7920</td>
			<td>22g x 1.5&#34;, 1.25 mm - straight</td>
		</tr>
		<tr>
			<td>Microprobe thermometer</td>
			<td>Physitemp</td>
			<td>BAT-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Rectal probe for mice</td>
			<td>Physitemp</td>
			<td>Ret-3</td>
			<td></td>
		</tr>
		<tr>
			<td>Cholera toxin, from vibrio cholera</td>
			<td>List Biological Laboratories, Inc.</td>
			<td>100B</td>
			<td>Azide free</td>
		</tr>
		<tr>
			<td>BCA Protein Assay Kit</td>
			<td>Pierce</td>
			<td>23225</td>
			<td></td>
		</tr>
		<tr>
			<td>Carbonate-bicarbonate buffer</td>
			<td>Sigma</td>
			<td>C3041</td>
			<td></td>
		</tr>
		<tr>
			<td>TMB Stop Solution</td>
			<td>KPL</td>
			<td>50-85-06</td>
			<td></td>
		</tr>
		<tr>
			<td>SureBlue TMB Microwell Peroxidase Substrate</td>
			<td>KPL</td>
			<td>5120-0077</td>
			<td></td>
		</tr>
		<tr>
			<td>96 well Immulon 4HBX plate</td>
			<td>Thermo Scientific</td>
			<td>3855</td>
			<td></td>
		</tr>
		<tr>
			<td>Purified soluble Ara h 2</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>purified as in: Sen, et al., 2002, Journal of Immunology</td>
		</tr>
		<tr>
			<td>HSA-DNP</td>
			<td>Sigma</td>
			<td>A-6661</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse IgE anti-DNP</td>
			<td>Accurate Chemical</td>
			<td>BYA60251</td>
			<td></td>
		</tr>
		<tr>
			<td>Sheep anti-Mouse IgE</td>
			<td>The Binding Site</td>
			<td>PC284</td>
			<td></td>
		</tr>
		<tr>
			<td>Biotinylated Donkey anti-Sheep IgG</td>
			<td>Accurate Chemical</td>
			<td>JNS065003</td>
			<td></td>
		</tr>
		<tr>
			<td>NeutrAvidin Protein, HRP</td>
			<td>ThermoFisher Scientific</td>
			<td>31001</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse IgG1 anti-DNP</td>
			<td>Accurate Chemical</td>
			<td>MADNP105</td>
			<td></td>
		</tr>
		<tr>
			<td>HRP Goat anti-mouse IgG1</td>
			<td>Southern Biotech</td>
			<td>1070-05</td>
			<td></td>
		</tr>
		<tr>
			<td>1 mL Insulin Syringes</td>
			<td>BD</td>
			<td>329412</td>
			<td>U-100 Insulin, 0.40 mm(27G) x 16.0 mm (5/8&#34;)</td>
		</tr>
		<tr>
			<td>Superfrost Microscope Slides</td>
			<td>Fisher Scientific</td>
			<td>12-550-14</td>
			<td>25 x 75 x 1.0 mm</td>
		</tr>
		<tr>
			<td>ACK Lysing Buffer</td>
			<td>gibco by Life Technologies</td>
			<td>A10492-01</td>
			<td>100 mL</td>
		</tr>
		<tr>
			<td>RPMI 1640 Medium</td>
			<td>Thermo Fisher Scientific</td>
			<td>11875093</td>
			<td>500 mL</td>
		</tr>
		<tr>
			<td>Cell Strainer</td>
			<td>Corning</td>
			<td>352350</td>
			<td>70 &#956;m Nylon, White, Sterile, Individually packaged</td>
		</tr>
		<tr>
			<td>NuPAGE 4-12% Bis-Tris Protein Gels</td>
			<td>Invitrogen</td>
			<td>NP0322BOX</td>
			<td>10 gels</td>
		</tr>
		<tr>
			<td>NuPAGE LDS buffer, 4X</td>
			<td>Invitrogen</td>
			<td>NP0008</td>
			<td>250 mL</td>
		</tr>
		<tr>
			<td>SeeBlue Plus2 Pre-stained standard</td>
			<td>Invitrogen</td>
			<td>LC5925</td>
			<td>500 &#181;L</td>
		</tr>
		<tr>
			<td>NuPAGE MES/SDS running buffer, 20X</td>
			<td>Invitrogen</td>
			<td>NP0002</td>
			<td>500 mL</td>
		</tr>
		<tr>
			<td>GelCode Blue Stain</td>
			<td>Thermo Scientific</td>
			<td>24590</td>
			<td>500 mL</td>
		</tr>
	</tbody>
</table>

antigenic liposomes for generation of disease-specific antibodies

Antibody responses provide critical protective immunity to a wide array of pathogens. There remains a high interest in generating robust antibodies for vaccination as well as understand how pathogenic antibody responses develop in allergies and autoimmune disease. Generating robust antigen-specific antibody responses is not always trivial. In mouse models, it often requires multiple rounds of immunizations with adjuvant that leads to a great deal of variability in the levels of induced antibodies. One example is in mouse models of peanut allergies where more robust and reproducible models that minimize mouse numbers and the use of adjuvant would be beneficial. Presented here is a highly reproducible mouse model of peanut allergy anaphylaxis. This new model relies on two key factors: (1) antigen-specific splenocytes are adoptively transferred from a peanut-sensitized mouse into a na&#239;ve recipient mouse, normalizing the number of antigen-specific memory B- and T-cells across a large number of mice; and (2) recipient mice are subsequently boosted with a strong multivalent immunogen in the form of liposomal nanoparticles displaying the major peanut allergen (Ara h 2). The major advantage of this model is its reproducibility, which ultimately lowers the number of animals used in each study, while minimizing the number of animals receiving multiple injections of adjuvant. The modular assembly of these immunogenic liposomes provides relatively facile adaptability to other allergic or autoimmune models that involve pathogenic antibodies.

Conjugation of the protein of interest with DSPE-PEG(2000) can be demonstrated by running a reducing showing an increase in molecular weight compared to the unconjugated protein. Figure 1A shows a representative gel of anti-mouse IgM F(ab) fragment conjugation to PEG-DSPE, which shows a 2&#8211;3 kDa bandshift for the denatured protein. Note that approximately 50% of the protein appears to be modified, which is expected given that 1:1 stoichiometry was achiev...

Watch this Scientific Journal Video about Antigenic Liposomes for Generation of Disease-specific Antibodies at JoVE.com

Antigenic Liposomes for Generation of Disease-specific Antibodies

Described is the preparation of antigenic liposomal nanoparticles and their use in stimulating B-cell activation in vitro and in vivo. Consistent and robust antibody responses led to the development of a new peanut allergy model. The protocol for generating antigenic liposomes can be extended to different antigens and immunization models.

Antibody responses provide critical protective immunity to a wide array of pathogens. There remains a high interest in generating robust antibodies for ...

This method can help answer key questions in the field of immunology, such as how are white blood cells activated, and how do allergies to individual allergens develop? The main advantage of this robust and reproducible allergy mouse model is that fewer mice can be used to yield a lower variance with an experimental population. New immunotherapies to control immune responses require robust mouse models as an initial means of testing in vivo efficacy.Thus, the implications of this technique extend toward allergy immunotherapy. Though this method can provide insight into allergies, it can also be applied to other systems, such as autoimmunity in which undesired antibody responses play a key role in disease. Generally, individuals new to this method will struggle because of lack of experience in working with liposomal nanoparticles or an inexperience with the techniques required in the mouse work.Begin by adding 2.5 molar equivalent of the heterobifunctional crosslinker to the protein and placing the reaction on an oscillating shaker at room temperature for approximately one hour. After a one-hour incubation with SPDP, desalt the protein on a column equilibrated in 100-millimolar sodium acetate, and collect the fractions. Determine the 280-nanometer absorbance, and pool the top fractions.Wash the column in PBS, and add 25-millimolar dithiothreitol, or DTT, to the pooled protein fractions for a five to 10-minute incubation. Then, measure the 280 and 343-nanometer absorbances of the protein to allow calculation of the linking ratio based on the molarity of protein and the linker. Next, run the pooled fractions of the PBS-washed column, and collect the fractions for measurement of the 280-nanometer and top fraction pooling as demonstrated.Add the appropriate volume of 100x DSPE-PEG2000-Maleimide to the protein to achieve a 1x, 10-fold molar excess final concentration with gentle swirling. Then, run the reaction overnight under nitrogen in a sealed round-bottom flask. The following day, run the protein over a crosslinked dextran gel bead column, and store the final pooled fractions of lipid-linked protein at four degrees Celsius until their use.Once the correct amount of each lipid has been calculated, combine all of the lipids into a 12-milliliter borosilicate glass test tube, and use a three-milliliter syringe and tubing to carefully blow the chloroform off with nitrogen. Then, lyophilize the solution with 100 microliters of DMSO overnight. The next morning, add one milliliter of lipid-linked protein to the 12-milliliter lipid tube, and sonicate the solution three to four times for 30 to 60 seconds per sonication in a sonication water bath with at least five-minute rests between sonications.After the last sonication, load the sample into one of the extruding syringes placed into the extruder, and place the extruder syringe into the other end of the extruder. The empty syringe will fill as the lipid is extruded through the polycarbonate 0.8-micrometer membrane. Place the fully assembled extruder into a heating block, and gently depress the plunger to empty the syringe.After the last extrusion, transfer the liposomes into a clean vial, and extrude the lipids through polycarbonate 0.2 and 0.1-micrometer membranes as just demonstrated. Then, store the liposomes at four degrees Celsius. To monitor B-cell response to antigenic liposome activation, resuspend 1.5 times 10 to the seventh splenocytes in calcium flux loading buffer, and add 1.5-micromolar Indo-1 to the cells, inverting the solution in the tube several times to mix.After a 30-minute water bath incubation at 37 degrees Celsius, protected from light, add five times the volume of calcium flux loading buffer, and centrifuge the Indo-1-labeled cells. For B-cell gating, stain cells with anti-CD5 and anti-B220 antibody in 0.5 milliliters of loading buffer at four degrees Celsius for 20 minutes, protected from light. At the end of the incubation, wash the cells in fresh calcium flux loading buffer, and resuspend the pellet at one to two times 10 to the seventh cells per milliliter of fresh calcium flux running buffer for storage on ice, protected from light until analysis.Next, add 0.5 milliliters of cells to a capped, five-milliliter, round-bottom, polystyrene tube, and warm the cells to 37 degrees Celsius in a water bath. After three to five minutes, transfer the tube to a 37-degree Celsius water-jacketed chamber connected to a recirculating water bath, and run the tube in the water-jacket on the flow cytometer. After collecting 5, 000 to 10, 000 events per second, allow the cells to stabilize for 15 to 30 seconds, and reinitiate the data acquisition, collecting the data for at least 10 seconds to establish a background reading.At the 10-second mark, quickly remove the tube from the flow cytometer, and add the appropriate experimental concentration of antigenic liposomes. Then, pulse vortex the cells, and read the tube on the cytometer for an additional three to five minutes. To sensitize the animals, deliver 200 microliters of peanut extract containing cholera toxin via oral gavage to each four to five-week-old BALB/c female mouse recipient once a week for three weeks and 300 microliters of diluted peanut extract in the fourth week.On day 28, prepare peanut extract to a final concentration of one milligram per milliliter in PBS, and use a rectal thermometer to measure the baseline body temperature of each sensitized animal. When all of the temperatures have been measured, administer 200 microliters of peanut extract to each recipient via intraperitoneal injection, and measure the body temperature with the rectal thermometer every 15 minutes for one hour after injection. A dip in body temperature indicates an allergy to peanut.After isolating splenocytes from the peanut-allergic mice, use a one-milliliter insulin syringe equipped with a 27-gauge, 5/8-inch needle to intravenously inject 1.5 times 10 to the seventh of the extracted allergic splenocytes into the tail veins of naive, unsensitized animals. One day after adoptive transfer, intravenously inject 200 microliters of Ara h 2 antigenic liposomes into the tail vein of each BALB/c mouse that received the allergic splenocytes. Two weeks after the liposome injection, boost the mice with an i.p.injection of soluble Ara h 2, followed by a 200-microliter Ara h 2 challenge on day 61. Then, measure the body temperatures with the rectal probe every 15 minutes as demonstrated. Protein conjugation can be demonstrated by running a reducing gel showing an increase in molecular weight compared to the unconjugated protein.To assess the antigenic liposome-stimulated B-cell calcium flux, gate the live single cells to allow selection of the B220-positive CD5-negative B cells. The ratio of Indo-1 violet versus Indo-1 blue fluorescence over time can then be analyzed to assess the amount of liposome-induced B-cell activation. The quantification of Ara h 2-specific IgE and IgG1 in the serum of peanut extract-sensitized mice by ELISA indicates that mice with conferred sensitivity that are boosted with Ara h 2 exhibit measurable Ara h 2-specific IgE and IgG1 in their serum.Body temperatures recorded during the Ara h 2 challenge reveal that allergic mice demonstrate decreased body temperatures following the challenge, while body temperatures in naive mice remain consistent. While attempting this procedure, it's important to remember to carefully keep track of the amount of lipid-linked protein being incorporated into the liposomes, as too much protein can make extrusion difficult. Following this procedure, other methods like the tracking and sorting of allergen-specific B and T cells can be performed to answer additional questions about how these allergen-specific cells respond to therapies.This technique will pave the way for researchers in the allergy field to explore new immunotherapies that combat allergic disease using this mouse model. Don't forget that working with cholera toxin can be hazardous and that the guidelines for its use should be followed according to your local institutional biological safety standards.

antigenic-liposomes-for-generation-of-disease-specific-antibodies

Research

JoVE Journal

Immunology and Infection

Quantitative Analyses of all Influenza Type A Viral Hemagglutinins and Neuraminidases using Universal Antibodies in Simple Slot Blot Assays

Hemagglutinin (HA) and neuraminidase (NA) are two surface proteins of influenza viruses which are known to play important roles in the viral life cycle and the induction of protective immune responses1,2. As the main target for neutralizing antibodies, HA is currently used as the influenza vaccine potency marker and is measured by single radial immunodiffusion (SRID)3. However, the dependence of SRID on the availability of the corresponding subtype-specific antisera causes a minimum of 2-3 months delay for the release of every new vaccine. Moreover, despite evidence that NA also induces protective immunity4, the amount of NA in influenza vaccines is not yet standardized due to a lack of appropriate reagents or analytical method5. Thus, simple alternative methods capable of quantifying HA and NA antigens are desirable for rapid release and better quality control of influenza vaccines.
Universally conserved regions in all available influenza A HA and NA sequences were identified by bioinformatics analyses6-7. One sequence (designated as Uni-1) was identified in the only universally conserved epitope of HA, the fusion peptide6, while two conserved sequences were identified in neuraminidases, one close to the enzymatic active site (designated as HCA-2) and the other close to the N-terminus (designated as HCA-3)7. Peptides with these amino acid sequences were synthesized and used to immunize rabbits for the production of antibodies. The antibody against the Uni-1 epitope of HA was able to bind to 13 subtypes of influenza A HA (H1-H13) while the antibodies against the HCA-2 and HCA-3 regions of NA were capable of binding all 9 NA subtypes. All antibodies showed remarkable specificity against the viral sequences as evidenced by the observation that no cross-reactivity to allantoic proteins was detected. These universal antibodies were then used to develop slot blot assays to quantify HA and NA in influenza A vaccines without the need for specific antisera7,8. Vaccine samples were applied onto a PVDF membrane using a slot blot apparatus along with reference standards diluted to various concentrations. For the detection of HA, samples and standard were first diluted in Tris-buffered saline (TBS) containing 4M urea while for the measurement of NA they were diluted in TBS containing 0.01% Zwittergent as these conditions significantly improved the detection sensitivity. Following the detection of the HA and NA antigens by immunoblotting with their respective universal antibodies, signal intensities were quantified by densitometry. Amounts of HA and NA in the vaccines were then calculated using a standard curve established with the signal intensities of the various concentrations of the references used. 
Given that these antibodies bind to universal epitopes in HA or NA, interested investigators could use them as research tools in immunoassays other than the slot blot only.

A simple slot blot method was developed for the quantification of influenza viral hemagglutinin and neuraminidase using universal antibodies targeting their most conserved sequences identified through bioinformatics analyses. This innovative approach may provide a useful alternative to quantitative determination of all viral hemagglutinin and neuraminidase.

Hemagglutinin (HA) and neuraminidase (NA) are two surface proteins of influenza viruses which are known to play important roles in the viral life cycle ...

IgY Technology: Extraction of Chicken Antibodies from Egg Yolk by Polyethylene Glycol (PEG) Precipitation

Hens can be immunized by means of i.m. vaccination (Musculus pectoralis, left and right, injection volume 0.5-1.0 ml) or by means of Gene-Gun plasmid-immunization. Dependent on the immunogenicity of the antigen, high antibody-titres (up to 1:100,000 - 1:1,000,000) can be achieved after only one or 3 - 4 boost immunizations. Normally, a hen lays eggs continuously for about 72 weeks, thereafter the laying capacity decreases. This protocol describes the extraction of total IgY from egg yolk by means of a precipitation procedure (PEG. Polson et al. 1980). The method involves two important steps. The first one is the removal of lipids and the second is the precipitation of total IgY from the supernatant of step one. After dialysis against a buffer (normally PBS) the IgY-extract can be stored at -20&deg;C for more than a year. The purity of the extract is around 80 %, the total IgY per egg varies from 40-80 mg, dependent on the age of the laying hen. The total IgY content increases with the age of the hen from around 40 mg/egg up to 80 mg/egg (concerning PEG precipitation). The laying capacity of a hen per year is around 325 eggs. That means a total potential harvest of 20 g total IgY/year based on a mean IgY content of 60 mg total IgY/egg (see Table 1).

IgY Technology: Extraction of Chicken Antibodies from Egg Yolk by Polyethylene Glycol PEG Precipitation

This protocol describes in particular the extraction of total IgY from egg yolk by means of polyethylene glycol precipitation and gives general information about IgY technology.

Hens can be immunized by means of  i.m. vaccination (Musculus pectoralis, left and right, injection volume  0.5-1.0 ml) or by means of Gene-Gun ...

Methodology for the Efficient Generation of Fluorescently Tagged Vaccinia Virus Proteins

Tagging of viral proteins with fluorescent proteins has proven an indispensable approach to furthering our understanding of virus-host interactions. Vaccinia virus (VACV), the live vaccine used in the eradication of smallpox, is particularly amenable to fluorescent live-cell microscopy owing to its large virion size and the ease with which it can be engineered at the genome level. We report here an optimized protocol for generating recombinant viruses. The minimal requirements for targeted homologous recombination during vaccinia replication were determined, which allows the simplification of construct generation. This enabled the alliance of transient dominant selection (TDS) with a fluorescent reporter and metabolic selection to provide a rapid and modular approach to fluorescently label viral proteins. By streamlining the generation of fluorescent recombinant viruses, we are able to facilitate downstream applications such as advanced imaging analysis of many aspects of the virus-host interplay that occurs during virus replication.

A rapid and modular protocol for the generation of recombinant vaccinia viruses expressing fluorescently&#160;tagged proteins simultaneously using the method of transient dominant selection is described here.

Tagging of viral proteins with fluorescent  proteins has proven an indispensable approach to furthering our understanding  of virus-host interactions. ...

Generation of Recombinant Human IgG Monoclonal Antibodies from Immortalized Sorted B Cells

Finding new methods for generating human monoclonal antibodies is an active research field that is important for both basic and applied sciences, including the development of immunotherapeutics. However, the techniques to identify and produce such antibodies tend to be arduous and sometimes the heavy and light chain pair of the antibodies are dissociated. Here, we describe a relatively simple, straightforward protocol to produce human recombinant monoclonal antibodies from human peripheral blood mononuclear cells using immortalization with Epstein-Barr Virus (EBV) and Toll-like receptor 9 activation. With an adequate staining, B cells producing antibodies can be isolated for subsequent immortalization and clonal expansion. The antibody transcripts produced by the immortalized B cell clones can be amplified by PCR, sequenced as corresponding heavy and light chain pairs and cloned into immunoglobulin expression vectors. The antibodies obtained with this technique can be powerful tools to study relevant human immune responses, including autoimmunity, and create the basis for new therapeutics.

Synthesis of human monoclonal antibodies is the first step in studies aimed at unraveling the pathophysiological mechanisms of auto-antibody-mediated immune responses. We have developed a protocol to generate recombinant human immunoglobulin G (IgG) monoclonal antibodies from blood sorted B cells, including B-cell isolation, antibody cloning and in vitro synthesis.

Finding new methods for generating human monoclonal antibodies is an active research field that is important for both basic and applied sciences, ...

Generation of Murine Monoclonal Antibodies by Hybridoma Technology

Monoclonal antibodies are universal binding molecules and are widely used in biomedicine and research. Nevertheless, the generation of these binding molecules is time-consuming and laborious due to the complicated handling and lack of alternatives. The aim of this protocol is to provide one standard method for the generation of monoclonal antibodies using hybridoma technology. This technology combines two steps. Step 1 is an appropriate immunization of the animal and step 2 is the fusion of B lymphocytes with immortal myeloma cells in order to generate hybrids possessing both parental functions, such as the production of antibody molecules and immortality. The generated hybridoma cells were then recloned and diluted to obtain stable monoclonal cell cultures secreting the desired monoclonal antibody in the culture supernatant. The supernatants were tested in enzyme-linked immunosorbent assays (ELISA) for antigen specificity. After the selection of appropriate cell clones, the cells were transferred to mass cultivation in order to produce the desired antibody molecule in large amounts. The purification of the antibodies is routinely performed by affinity chromatography. After purification, the antibody molecule can be characterized and validated for the final test application. The whole process takes 8 to 12 months of development, and there is a high risk that the antibody will not work in the desired test system.

An optimized protocol is presented for the generation of monoclonal antibodies based on the hybridoma technology. Mice were immunized with an immunoconjugate. Spleen cells were fused by PEG and an electric impulse with immortal myeloma cells. Antibody-producing hybridoma cells were selected by HAT and antigen-specific ELISA screening.

Monoclonal antibodies are universal binding molecules and are widely used in biomedicine and research. Nevertheless, the generation of these binding ...

Flow Virometry to Analyze Antigenic Spectra of Virions and Extracellular Vesicles

Cells release small extracellular vesicles (EVs) into the surrounding media. Upon virus infection cells also release virions that have the same size of some of the EVs. Both virions and EVs carry proteins of the cells that generated them and are antigenically heterogeneous. In spite of their diversity, both viruses and EVs were characterized predominantly by bulk analysis. Here, we describe an original nanotechnology-based high throughput method that allows the characterization of antigens on individual small particles using regular flow cytometers. Viruses or extracellular vesicles were immunocaptured with 15 nm magnetic nanoparticles (MNPs) coupled to antibodies recognizing one of the surface antigens. The captured virions or vesicles were incubated with fluorescent antibodies against other surface antigens. The resultant complexes were separated on magnetic columns from unbound antibodies and analyzed with conventional flow cytometers triggered on fluorescence. This method has wide applications and can be used to characterize the antigenic composition of any viral- and non-viral small particles generated by cells in vivo and in vitro. Here, we provide examples of the usage of this method to evaluate the distribution of host cell markers on individual HIV-1 particles, to study the maturation of individual Dengue virions (DENV), and to investigate extracellular vesicles released into the bloodstream.

Viruses or extracellular vesicles were immunocaptured with 15 nm magnetic nanoparticles coupled to antibodies recognizing surface antigens. The captured virions or vesicles were labeled with fluorescent antibodies against other surface antigens. The resultant complexes were separated in high magnetic field and analyzed with conventional flow cytometers triggered on fluorescence.

Cells release small extracellular vesicles (EVs) into the surrounding media. Upon virus infection cells also release virions that have the same size of ...

Generation of Escape Variants of Neutralizing Influenza Virus Monoclonal Antibodies

Influenza viruses exhibit a remarkable ability to adapt and evade the host immune response. One way is through antigenic changes that occur on the surface glycoproteins of the virus. The generation of escape variants is a powerful method in elucidating how viruses escape immune detection and in identifying critical residues required for antibody binding. Here, we describe a protocol on how to generate influenza A virus escape variants by utilizing human or murine monoclonal antibodies (mAbs) directed against the viral hemagglutinin (HA). With the use of our technique, we previously characterized critical residues required for the binding of antibodies targeting either the head or stalk of the novel avian H7N9 HA. The protocol can be easily adapted for other virus systems. Analyses of escape variants are important for modeling antigenic drift, determining single nucleotide polymorphisms (SNPs) conferring resistance and virus fitness, and in the designing of vaccines and/or therapeutics.

We describe a method by which we identify critical residues required for the binding of human or murine monoclonal antibodies that target the viral hemagglutinin of influenza A viruses. The protocol can be adapted to other virus surface glycoproteins and their corresponding neutralizing antibodies.

Influenza viruses exhibit a remarkable ability to adapt and evade the host immune response. One way is through antigenic changes that occur on the surface ...

Generation of Discriminative Human Monoclonal Antibodies from Rare Antigen-specific B Cells Circulating in Blood

Monoclonal antibodies (mAbs) are powerful tools useful for both fundamental research and in biomedicine. Their high specificity is indispensable when the antibody needs to distinguish between highly related structures (e.g., a normal protein and a mutated version thereof). The current way of generating such discriminative mAbs involves extensive screening of multiple Ab-producing B cells, which is both costly and time consuming. We propose here a rapid and cost-effective method for the generation of discriminative, fully human mAbs starting from human blood circulating B lymphocytes. The originality of this strategy is due to the selection of specific antigen binding B cells combined with the counter-selection of all other cells, using readily available Peripheral Blood Mononuclear Cells (PBMC). Once specific B cells are isolated, cDNA (complementary deoxyribonucleic acid) sequences coding for the corresponding mAb are obtained using single cell Reverse Transcription-Polymerase Chain Reaction (RT-PCR) technology and subsequently expressed in human cells. Within as little as 1 month, it is possible to produce milligrams of highly discriminative human mAbs directed against virtually any desired antigen naturally detected by the B cell repertoire.

We describe a method for the production of human antibodies specific for an antigen of interest, starting from rare B cells circulating in human blood. Generation of these natural antibodies is efficient and rapid, and the antibodies obtained can discriminate between highly related antigens.

Monoclonal antibodies (mAbs) are powerful tools useful for both fundamental research and in biomedicine. Their high specificity is indispensable when the ...

Generation of Monoclonal Antibodies Against Natural Products

The analysis of the bioactive components present in foods and natural products has become a popular area of study in many fields, including traditional Chinese medicine and food safety/toxicology. Many of the classical analysis techniques require expensive equipment and/or expertise. Notably, enzyme-linked immunosorbent assays (ELISAs) have become an emerging method for the analysis of foods and natural products. This method is based on antibody-mediated detection of the target components. However, as many of the bioactive components in natural products are small (&lt;1,000 Da) and do not induce an immune response, creating monoclonal antibodies (mAbs) against them is often difficult. In this protocol, we provide a detailed explanation of the steps required to generate mAbs against target molecules as well as those needed to create the associated indirect competitive (ic)ELISA for the rapid analysis of the compound in multiple samples. The procedure describes the synthesis of the artificial antigen (i.e., the hapten-carrier conjugate), immunization, cell fusion, monoclonal hybridoma preparation, characterization of the mAb, and the ELISA-based application of the mAb. The hapten-carrier conjugate was synthesized by the sodium periodate method and evaluated by MALDI-TOF-MS. After immunization, splenocytes were isolated from the immunized mouse with the highest antibody titer and fused with the hypoxanthine-aminopterin-thymidine (HAT)-sensitive mouse myeloma cell line Sp2/0 -Ag14 using a polyethylene glycol (PEG)-based method. The hybridomas secreting mAbs reactive to the target antigen were screened by icELISA for specificity and cross-reactivity. Furthermore, the limiting dilution method was applied to prepare monoclonal hybridomas. The final mAbs were further characterized by icELISA and then utilized in an ELISA-based application for the rapid and convenient detection of the example hapten (naringin (NAR)) in natural products.

This article provides a detailed protocol for the preparation and evaluation of monoclonal antibodies against natural products for use in various immunoassays. This procedure includes immunization, cell fusion, indirect competitive ELISA for positive clone screening, and monoclonal hybridoma preparation. The specifications for antibody characterization using MALDI-TOF-MS and ELISA analyses are also provided.

The analysis of the bioactive components present in foods and natural products has become a popular area of study in many fields, including traditional ...

Targeted Antibody Blocking by a Dual-Functional Conjugate of Antigenic Peptide and Fc-III Mimetics (DCAF)

Elimination of harmful antibodies from organisms is a valuable approach for the intervention of antibody-associated diseases, such as Dengue hemorrhagic fever and autoimmune diseases. Since thousands of antibodies with different epitopes are circulating in blood, no universal method, except for the dual-functional conjugate of antigenic peptide and Fc-III mimetics (DCAF), was reported to target specific harmful antibodies. The development of DCAF molecules makes significant contribution to the progress of targeted therapy, which were demonstrated to eliminate the antibody dependent enhancement (ADE) effect in a Dengue virus (DENV) infection model and to boost the acetylcholine receptor activity in a myasthenia gravis model. Here, we describe a protocol for the synthesis of a DCAF molecule (DCAF1), which can selectively block 4G2 antibody to attenuate ADE effect during Dengue virus infection, and illustrate the binding of DCAF1 to 4G2 antibody by an ELISA assay. In our method, DCAF1 is synthesized by the conjugation of a hydrazine derivative of a Fc-III peptide and a recombinant expressed long &#945;-helix with antigenic sequence through native chemical ligation (NCL). This protocol has been successfully applied to DCAF1 as well as other DCAF molecules for targeting their cognate antibodies.

Targeted Antibody Blocking by a Dual-Functional Conjugate of Antigenic Peptide and Fc-III Mimetics DCAF

Development of a dual-functional conjugate of antigenic peptide and Fc-III mimetics (DCAF) is novel for the elimination of harmful antibodies. Here, we describe a detailed protocol for the synthesis of DCAF1 molecule, which can selectively block 4G2 antibody to eliminate antibody dependent enhancement effect during Dengue virus infection.

Elimination of harmful antibodies from organisms is a valuable approach for the intervention of antibody-associated diseases, such as Dengue hemorrhagic ...