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

<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. W., Patrick, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+myasthenia+gravis.+A+murine+system.">Experimental myasthenia gravis. A murine system.</a> J Exp Med. 151 (1), 204-223 (1980).</li><li>Berman, P. W., Patrick, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Linkage+between+the+frequency+of+muscular+weakness+and+loci+that+regulate+immune+responsiveness+in+murine+experimental+myasthenia+gravis.">Linkage between the frequency of muscular weakness and loci that regulate immune responsiveness in murine experimental myasthenia gravis.</a> J Exp Med. 152 (3), 507-520 (1980).</li><li>Derksen, V., Huizinga, T. W. J., van der Woude, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+autoantibodies+in+the+pathophysiology+of+rheumatoid+arthritis.">The role of autoantibodies in the pathophysiology of rheumatoid arthritis.</a> Seminars in Immunopathology. 39 (4), 437-446 (2017).</li></ol>

The authors have nothing to disclose.

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>1 mL syringe with holder/heating block</td></tr><tr><td>Filters 0.1 &amp;micro;m</td><td>Avanti</td><td>610005</td><td></td></tr><tr><td>Filters 0.8 &amp;micro;m</td><td>Avanti</td><td>610009</td><td></td></tr><tr><td>10 mm 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 (1 M)</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>MgCl&lt;sub&gt;2&lt;/sub&gt;</td><td>Sigma</td><td>M8266</td><td></td></tr><tr><td>CaCl&lt;sub&gt;2&lt;/sub&gt;</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&#039;)&lt;sub&gt;2&lt;/sub&gt; 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&quot;, 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 &lt;em&gt;Vibrio cholera&lt;/em&gt;</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, &lt;em&gt;et al.&lt;/em&gt;, 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 (27 G) x 16.0 mm (5/8&quot;)</td></tr><tr><td>Superfrost Microscope Slides</td><td>Fisher Scientific</td><td>12-550-14</td><td>25 mm x 75 mm 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 &amp;mu;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 &amp;micro;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 ...

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

Research

JoVE Journal

Immunology and Infection

12.3K Views.  Janssen R&D. Deze methode kan helpen bij het beantwoorden van belangrijke vragen op het gebied van immunologie, zoals hoe witte bloedcellen geactiveerd, en hoe allergieën voor individuele allergenen ontwikkelen? Het belangrijkste voordeel van dit robuuste en reproduceerbare allergiemuismodel is dat minder muizen kunnen worden gebruikt om een lagere variantie met een experimentele populatie op te leveren. Nieuwe immunotherapieën om immuunreacties te controleren vereisen robuuste muismodellen als een eers...

Video: Antigenic Liposomes for Generation of Disease-specific Antibodies

Cell-Free Production of Proteoliposomes for Functional Analysis and Antibody Development Targeting Membrane Proteins

Membrane proteins play essential roles in a variety of cellular processes and perform vital functions. Membrane proteins are medically important in drug discovery because they are the targets of more than half of all drugs. An obstacle to conducting biochemical, biophysical, and structural studies of membrane proteins as well as antibody development has been the difficulty in producing large amounts of high-quality membrane protein with correct conformation and activity. Here we describe a &#8220;bilayer-dialysis method&#8221; using a wheat germ cell-free system, liposomes, and dialysis cups to efficiently synthesize membrane proteins and prepare purified proteoliposomes in a short time with a high success rate. Membrane proteins can be produced as much as in several milligrams, such as GPCRs, ion channels, transporters, and tetraspanins. This cell-free method contributes to reducing the time, cost and effort for preparing high-quality proteoliposomes, and provides suitable means for functional analysis of membrane proteins, drug targets screening, and antibody development.

This protocol describes an efficient cell-free method for production of high-quality proteoliposome by bilayer-dialysis method using wheat cell-free system and liposomes. This method provides suitable means for functional analysis of membrane proteins, drug targets screening, and antibody development.

Membrane proteins play essential roles in a variety of cellular processes and perform vital functions. Membrane proteins are medically important in drug ...

Biochemistry

Antibody Profiling by Luciferase Immunoprecipitation Systems (LIPS)

Technologies for comprehensively understanding and quantifying antibody profiles to autoantigens and infectious agents may yield new insights into disease mechanisms and may elucidate new markers to substratify disease with different clinical features and better understand pathogenesis. We have developed a highly quantitative method called Luciferase Immunoprecipitation Systems (LIPS) for profiling patient sera antibody responses to autoantigens and pathogen antigens associated with infection. Unlike ELISAs, the highly sensitive LIPS is easily implemented to survey humoral serological response profiles to different antigens in a universal format and produces dynamic antibody titer ranges up to 6 log10 for some antigens. In these studies, quantitative profiling by LIPS of patient humoral responses against panels of antigens or even the entire proteome of some pathogens (i.e. HIV), is typically more informative than testing a single antigen by ELISA. In addition, LIPS also eliminates time and effort needed to produce highly purified antigens as well as the labor-intensive assay optimization steps needed for standard ELISAs. Here we provide a detailed protocol describing the technical aspects of performing LIPS assays for readily profiling antibody responses to single or multiple antigens.

Antibody Profiling by Luciferase Immunoprecipitation Systems LIPS

The technical aspects of performing LIPS (Luciferase Immunoprecipitation Systems) are described. The overall approach involves expressing chimeric genes encoding antigens fused to Renilla luciferase (Ruc) in mammalian cells. Crude Ruc-antigen extracts are then prepared and, without purification, employed in immunoprecipitation assays to quantify antibodies.

Technologies for comprehensively understanding and quantifying antibody profiles to autoantigens and infectious agents may yield new insights into disease ...

Biology

Delivery of Therapeutic siRNA to the CNS Using Cationic and Anionic Liposomes

Prion diseases result from the misfolding of the normal, cellular prion protein (PrPC) to an abnormal protease resistant isomer called PrPRes. The emergence of prion diseases in wildlife populations and their increasing threat to human health has led to increased efforts to find a treatment for these diseases. Recent studies have found numerous anti-prion compounds that can either inhibit the infectious PrPRes isomer or down regulate the normal cellular prion protein. However, most of these compounds do not cross the blood brain barrier to effectively inhibit PrPRes formation in brain tissue, do not specifically target neuronal PrPC, and are often too toxic to use in animal or human subjects. 
We investigated whether siRNA delivered intravascularly and targeted towards neuronal PrPC is a safer and more effective anti-prion compound. This report outlines a protocol to produce two siRNA liposomal delivery vehicles, and to package and deliver PrP siRNA to neuronal cells. The two liposomal delivery vehicles are 1) complexed-siRNA liposome formulation using cationic liposomes (LSPCs), and 2) encapsulated-siRNA liposome formulation using cationic or anionic liposomes (PALETS). For the LSPCs, negatively charged siRNA is electrostatically bound to the cationic liposome. A positively charged peptide (RVG-9r [rabies virus glycoprotein]) is added to the complex, which specifically targets the liposome-siRNA-peptide complexes (LSPCs) across the blood brain barrier (BBB) to acetylcholine expressing neurons in the central nervous system (CNS). For the PALETS (peptide addressed liposome encapsulated therapeutic siRNA), the cationic and anionic lipids were rehydrated by the PrP siRNA. This procedure results in encapsulation of the siRNA within the cationic or anionic liposomes. Again, the RVG-9r neuropeptide was bound to the liposomes to target the siRNA/liposome complexes to the CNS. Using these formulations, we have successfully delivered PrP siRNA to AchR-expressing neurons, and decreased the PrPC expression of neurons in the CNS.

The goal of this protocol is to use cationic/anionic liposomes with a neuro-targeting peptide as a CNS delivery system to enable siRNA to cross the BBB. The optimization of a delivery system for treatments, like siRNA, would allow for more treatment options for prion and other neurodegenerative diseases.

Prion diseases result from the misfolding of the normal, cellular prion protein (PrPC) to an abnormal protease resistant isomer called PrPRes.  The ...

Bioengineering

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 ...

Generation of Cationic Nanoliposomes for the Efficient Delivery of In Vitro Transcribed Messenger RNA

The development of messenger RNA (mRNA)-based therapeutics for the treatment of various diseases becomes more and more important because of the positive properties of in vitro transcribed (IVT) mRNA. With the help of IVT mRNA, the de novo synthesis of a desired protein can be induced without changing the physiological state of the target cell. Moreover, protein biosynthesis can be precisely controlled due to the transient effect of IVT mRNA.
For the efficient transfection of cells, nanoliposomes (NLps) may represent a safe and efficient delivery vehicle for therapeutic mRNA. This study describes a protocol to generate safe and efficient cationic NLps consisting of DC-cholesterol and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) as a delivery vector for IVT mRNA. NLps having a defined size, a homogeneous distribution, and a high complexation capacity, and can be produced using the dry-film method. Moreover, we present different test systems to analyze their complexation and transfection efficacies using synthetic enhanced green fluorescent protein (eGFP) mRNA, as well as their effect on cell viability. Overall, the presented protocol provides an effective and safe approach for mRNA complexation, which may advance and improve the administration of therapeutic mRNA.

Generation of Cationic Nanoliposomes for the Efficient Delivery of In Vitro Transcribed Messenger RNA

Here we describe a protocol for the generation of cationic nanoliposomes, which is based on the dry-film method and can be used for the safe and efficient delivery of in vitro transcribed messenger RNA.

The development of messenger RNA (mRNA)-based therapeutics for the treatment of various diseases becomes more and more important because of the positive ...

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 ...

Tetrameric Fluorescent Antigen Arrays for Single-Step Identification of Antigen-Specific B Cells

Fluorescent antigen production is a critical step in the identification of antigen-specific B cells. Here, we detailed the preparation, purification, and the use of four-arm, fluorescent PEG-antigen conjugates to selectively identify antigen-specific B cells through avid engagement with cognate B cell receptors. Using modular click chemistry and commercially available fluorophore kit chemistries, we demonstrated the versatility of preparing customized fluorescent PEG-conjugates by creating distinct arrays for proteolipid protein (PLP139-151) and insulin, which are important autoantigens in murine models of multiple sclerosis and type 1 diabetes, respectively. Assays were developed for each fluorescent conjugate in its respective disease model using flow cytometry. Antigen arrays were compared to monovalent autoantigen to quantify the benefit of multimerization onto PEG backbones. Finally, we illustrated the utility of this platform by isolating and assessing anti-insulin B cell responses after antigen stimulation ex vivo. Labeling insulin-specific B cells enabled the amplified detection of changes to co-stimulation (CD86) that were otherwise dampened in aggregate B cell analysis. Together, this report enables the production and use of fluorescent antigen arrays as a robust tool for probing B cell populations.

This protocol details the customizable production and use of fluorescent probes for labeling antigen-specific B cells.

Fluorescent antigen production is a critical step in the identification of antigen-specific B cells. Here, we detailed the preparation, purification, and ...

Detection of Neutralization-sensitive Epitopes in Antigens Displayed on Virus-Like Particle (VLP)-Based Vaccines Using a Capture Assay

The virus-like particle (VLP) capture assay is an immunoprecipitation method, commonly known as a &#39;pull-down assay&#39; used to purify and isolate antigen-displaying VLPs. Surface antigen-specific antibodies are coupled to, and thus immobilized on a solid and insoluble matrix such as beads. Due to their high affinity to the target antigen, these antibodies can capture VLPs decorated with the cognate antigen anchored in the membrane envelope of the VLPs. This protocol describes the binding of antigen-specific antibodies to protein A- or G-conjugated magnetic beads. In our study, human immunodeficiency virus (HIV)-derived VLPs formed by the group-specific antigen (Gag) viral core precursor protein p55 Gag and displaying the envelope glycoproteins (Env) of HIV are examined. The VLPs are captured utilizing broadly neutralizing antibodies (bNAbs) directed against neutralization-sensitive epitopes in Env. The VLP capture assay outlined here represents a sensitive and easy-to-perform method to demonstrate that (i) the VLPs are decorated with the respective target antigen, (ii) the surface antigen retained its structural integrity as demonstrated by the epitope-specific binding of bNAbs used in the assay and (iii) the structural integrity of the VLPs revealed by the detection of Gag proteins in a subsequent Western blot-analysis. Consequently, the utilization of bNAbs for immunoprecipitation facilitates a prediction of whether VLP vaccines will be able to elicit a neutralizing B cell response in vaccinated humans. We anticipate that this protocol will furnish other researchers with a valuable and straightforward experimental approach to examine potential VLP-based vaccines.

Detection of Neutralization-sensitive Epitopes in Antigens Displayed on Virus-Like Particle VLP-Based Vaccines Using a Capture Assay

Here, we present a protocol to detect neutralization epitopes on antigen-displaying virus-like particles (VLPs). Immunoprecipitation of the human immunodeficiency virus (HIV)-derived VLPs is performed using envelope glycoproteins-specific monoclonal antibodies coupled to protein G-conjugated magnetic beads. Captured VLPs are subsequently subjected to SDS-PAGE and Western blot-analysis employing viral core protein Gag-specific antibodies.

The virus-like particle (VLP) capture assay is an immunoprecipitation method, commonly known as a &#39;pull-down assay&#39; used to purify and isolate ...

Generating a Multivalent-Displaying Outer Membrane Vesicle Vaccine

Source: Feng, R., et al. <a href="https://app.jove.com/v/64213">A &#34;Plug-And-Display&#34; Nanoparticle Vaccine Platform Based on Outer Membrane Vesicles Displaying SARS-CoV-2 Receptor-Binding Domain.</a> J. Vis. Exp. (2022).
This video demonstrates a method to generate multivalent-displaying outer membrane vesicle (OMV) vaccines. Mammalian cells are transfected to express and secrete viral antigens fused to a SpyTag and a polyhistidine tag. These antigens are then purified using a nickel-nitrilotriacetic acid (Ni-NTA) affinity column. The purified antigen is mixed with outer membrane vesicles expressing surface-bound SpyCatcher (SC) protein. Multiple antigens covalently attach to SpyCatchers via their SpyTags (ST), creating OMVs that display the antigen, serving as a multivalent vaccine.

1. Plasmid construction

	Insert DNA encoding SpyCatcher sequence (Figure 1) into an ampicillin-resistant pThioHisA-Cytolysin A (ClyA) plasmid (see Table ...

JoVE Encyclopedia of Experiments

Immunology

Immunotherapy

Immunogenics and Vaccine Development

A Technique to Generate Monoclonal Antibodies from Antigen-Specific B Cells

Source: Devilder, M., et al. <a href="https://app.jove.com/v/56508">Generation of Discriminative Human Monoclonal Antibodies from Rare Antigen-specific B Cells Circulating in Blood.</a> J. Vis. Exp. (2018).
The video demonstrates a technique for generating monoclonal antibodies from antigen-specific B cells. Eukaryotic expression vectors encoding the heavy and light chains of antibodies, cloned from isolated antigen-specific B cells, are introduced into mammalian cells using polyplexes. Once inside the cells, these vectors undergo translation, and the resulting heavy and light chain peptides assemble into antibodies, which are subsequently secreted by the cells.

Antigenic Liposomes for Generation of Disease-specific Antibodies

Samenvatting

Meer video's verkennen