{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T00:40:20Z","timestamp":1759970420827,"version":"build-2065373602"},"reference-count":59,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,1,18]],"date-time":"2025-01-18T00:00:00Z","timestamp":1737158400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"U.S. Department of Veterans Affairs","award":["W81XWH-17-1-0677"],"award-info":[{"award-number":["W81XWH-17-1-0677"]}]},{"name":"American Legion Brain Sciences Chair of the University of Minnesota Foundation","award":["W81XWH-17-1-0677"],"award-info":[{"award-number":["W81XWH-17-1-0677"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: Anthrax is a serious disease caused by Bacillus anthracis (B. anthracis) with a very high mortality when the spores of B. anthracis are inhaled (inhalational anthrax). Aerosolized B. anthracis spores can be used as a deadly bioweapon. Vaccination against anthrax is the only effective preventive measure and, hence, the anthrax vaccine was administered to United States (and other) troops during the 1990\u201391 Gulf War. However, the anthrax vaccine is not harmless, and the anthrax vaccination has been linked to the occurrence and severity of Gulf War Illness (GWI), a debilitating Chronic Multisymptom Illness (CMI). We hypothesized that this is partly due to the combination of two factors, namely (a) the cytotoxicity of the antigen (anthrax Protective Antigen, PA) contained in the vaccine, and (b) the Human Leukocyte Antigen (HLA) genotype of susceptible vaccinees, reducing their ability to make antibodies against the cytotoxic PA. Method: Here, we tested this hypothesis by determining the association between severity of GWI symptoms in 458 GW veterans and the overall strength of the binding affinity of the PA epitopes to the specific six Human Leukocyte Antigen (HLA) Class II alleles carried by each individual (two of each of the HLA-II genes: DPB1, DQB1, DRB1), responsible for initiating the process of antibody production in otherwise immunocompetent individuals, estimated in silico. Results: We found that the severity of GWI symptomatology was negatively and significantly correlated with the strength of the predicted binding affinity of PA peptides to HLA-II molecules (r=\u22120.356,\u00a0p&lt;0.001); the stronger the overall binding affinity, the weaker the symptoms. Since the binding of a peptide to an HLA-II molecule is the first and necessary step in initiating the production of antibodies, the findings above support our hypothesis that the severity of GWI symptomatology is partly due to a lack of HLA-II protection. Conclusions: Reduced HLA protection against the toxic anthrax vaccine may underlie GWI.<\/jats:p>","DOI":"10.3390\/vaccines13010088","type":"journal-article","created":{"date-parts":[[2025,1,21]],"date-time":"2025-01-21T08:46:26Z","timestamp":1737449186000},"page":"88","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Negative Association of Gulf War Illness Symptomatology with Predicted Binding Affinity of Anthrax Vaccine Antigen to Human Leukocyte (HLA) Class II Molecules"],"prefix":"10.3390","volume":"13","author":[{"given":"Lisa M.","family":"James","sequence":"first","affiliation":[{"name":"The GWI and HLA Research Groups, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN 55417, USA"},{"name":"Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA"},{"name":"Department of Psychiatry, University of Minnesota Medical School, Minneapolis, MN 55455, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Apostolos P.","family":"Georgopoulos","sequence":"additional","affiliation":[{"name":"The GWI and HLA Research Groups, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN 55417, USA"},{"name":"Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,1,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Georgopoulos, A.P., and James, L.M. (2024). Anthrax Vaccines in the 21st Century. Vaccines, 12.","DOI":"10.3390\/vaccines12020159"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"James, L.M., Carpenter, A.F., Engdahl, B.E., Johnson, R.A., Lewis, S.M., and Georgopoulos, A.P. (2024). Anthrax Vaccination, Gulf War Illness, and Human Leukocyte Antigen (HLA). Vaccines, 12.","DOI":"10.3390\/vaccines12060613"},{"key":"ref_3","unstructured":"IOM Committee on the Development of a Consensus Case Definition for Chronic Multisymptom Illness in 1990\u20131991 Gulf War Veterans, Board on the Health of Select Populations, and Institute of Medicine (2014). Chronic Multisymptom Illness in Gulf War Veterans: Case Definitions Reexamined, National Academies Press."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1330","DOI":"10.1128\/CVI.00103-08","article-title":"Toxicity of anthrax toxin is influenced by receptor expression","volume":"15","author":"Taft","year":"2008","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2633105520931966","DOI":"10.1177\/2633105520931966","article-title":"Anthrax protective antigen 63 (PA63): Toxic effects in neural cultures and role in Gulf War Illness (GWI)","volume":"15","author":"Tsilibary","year":"2020","journal-title":"Neurosci. Insights"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.ebiom.2015.11.037","article-title":"Reduced Human Leukocyte Antigen (HLA) protection in Gulf War Illness (GWI)","volume":"3","author":"Georgopoulos","year":"2016","journal-title":"eBioMedicine"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Doganay, M., Dinc, G., Kutmanova, A., and Baillie, L. (2023). Human Anthrax: Update of the diagnosis and treatment. Diagnostics, 13.","DOI":"10.3390\/diagnostics13061056"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"S341","DOI":"10.1093\/cid\/ciac534","article-title":"Clinical features of patients hospitalized for all routes of Anthrax, 1880\u20132018: A Systematic Review","volume":"75","author":"Hendricks","year":"2022","journal-title":"Clin. Infect. Dis."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"20877","DOI":"10.2807\/1560-7917.ES2014.19.32.20877","article-title":"Injectional anthrax\u2014New presentation of an old disease","volume":"19","author":"Berger","year":"2014","journal-title":"Euro Surveill."},{"key":"ref_10","first-page":"1","article-title":"Anthrax\u2014Biological Threat in the 21st Century","volume":"9","author":"Johari","year":"2002","journal-title":"Malays. J. Med. Sci."},{"key":"ref_11","first-page":"13","article-title":"How To Weaponize Anthrax?","volume":"9","author":"Dizer","year":"2004","journal-title":"Eastern J. Med."},{"key":"ref_12","unstructured":"Fulco, C.E., Liverman, C.T., and Sox, H.C. (2000). Gulf War and Health: Volume 1. Depleted Uranium, Sarin, Pyridostigmine Bromide, Vaccines, National Academies Press (US)."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"330","DOI":"10.1128\/am.11.4.330-334.1963","article-title":"Large-scale production of protective antigen of Bacillus anthracis in anaerobic cultures","volume":"11","author":"Puziss","year":"1963","journal-title":"Appl. Microbiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1128\/CVI.00321-07","article-title":"Neutralizing activity of vaccine-induced antibodies to two Bacillus anthracis toxin components, lethal factor and edema factor","volume":"15","author":"Taft","year":"2008","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Dumas, E.K., Gross, T., Larabee, J., Pate, L., Cuthbertson, H., Charlton, S., Hallis, B., Engler, R.J.M., Collins, L.C., and Spooner, C.E. (2017). Anthrax vaccine precipitated induces edema toxin-neutralizing, edema factor-specific antibodies in human recipients. Clin. Vaccine Immunol., 24.","DOI":"10.1128\/CVI.00165-17"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3416","DOI":"10.1016\/j.vaccine.2017.05.006","article-title":"Lethal factor antibodies contribute to lethal toxin neutralization in recipients of anthrax vaccine precipitated","volume":"35","author":"Dumas","year":"2017","journal-title":"Vaccine"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1512","DOI":"10.1128\/CVI.00469-14","article-title":"Comprehensive analysis and selection of anthrax vaccine adsorbed immune correlates of protection in rhesus macaques","volume":"21","author":"Chen","year":"2014","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"356","DOI":"10.1128\/iai.52.2.356-363.1986","article-title":"Development of antibodies to protective antigen and lethal factor components of anthrax toxin in humans and guinea pigs and their relevance to protective immunity","volume":"52","author":"Turnbull","year":"1986","journal-title":"Infect. Immun."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1080\/21645515.2020.1799668","article-title":"Characterization of the UK anthrax vaccine and human immunogenicity","volume":"17","author":"Modi","year":"2021","journal-title":"Hum. Vaccines Immunother."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1146\/annurev-immunol-032712-095910","article-title":"Pathways of antigen processing","volume":"31","author":"Blum","year":"2013","journal-title":"Annu. Rev. Immunol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"9710376","DOI":"10.1155\/2022\/9710376","article-title":"Human Leukocyte Antigen (HLA) System: Genetics and Association with Bacterial and Viral Infections","volume":"2022","author":"Medhasi","year":"2022","journal-title":"J. Immunol. Res."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"751","DOI":"10.1038\/s41577-022-00707-2","article-title":"A guide to antigen processing and presentation","volume":"22","author":"Pishesha","year":"2022","journal-title":"Nat. Rev. Immunol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1016\/j.it.2005.09.011","article-title":"Understanding specificity and sensitivity of T-cell recognition","volume":"26","author":"George","year":"2005","journal-title":"Trends Immunol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1038\/nature01076","article-title":"Direct observation of ligand recognition by T cells","volume":"419","author":"Irvine","year":"2002","journal-title":"Nature"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1038\/363156a0","article-title":"Induction of T-cell anergy by altered T-cell-receptor ligand on live antigen-presenting cells","volume":"363","author":"Evavold","year":"1993","journal-title":"Nature"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"981","DOI":"10.1001\/jama.280.11.981","article-title":"Chronic multisymptom illness affecting Air Force veterans of the Gulf War","volume":"280","author":"Fukuda","year":"1998","journal-title":"JAMA"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1682\/JRRD.2014.10.0255","article-title":"Iraq and Afghanistan Veterans report symptoms consistent with chronic multisymptom illness one year after deployment","volume":"53","author":"McAndrew","year":"2016","journal-title":"J. Rehabil. Res. Dev."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1186\/1477-7525-11-73","article-title":"What pre-deployment and early post-deployment factors predict health function after combat deployment?: A prospective longitudinal study of Operation Enduring Freedom (OEF)\/Operation Iraqi Freedom (OIF) soldiers","volume":"11","author":"McAndrew","year":"2013","journal-title":"Health Qual. Life Outcomes"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1016\/j.cortex.2015.08.022","article-title":"Recent research on Gulf War illness and other health problems in veterans of the 1991 Gulf War: Effects of toxicant exposures during deployment","volume":"74","author":"White","year":"2016","journal-title":"Cortex"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.29245\/2572.942X\/2019\/6.1255","article-title":"Anthrax and Gulf War Illness (GWI): Evidence for the Presence of Harmful Anthrax Antigen PA63 In the Serum of Veterans with GWI","volume":"4","author":"Tsilibary","year":"2019","journal-title":"J. Neurol. Neuromed."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"26331055221114817","DOI":"10.1177\/26331055221114817","article-title":"At the root of 3 \u201cLong\u201d diseases: Persistent antigens inflicting chronic damage on the brain and other organs in gulf war illness, Long-COVID-19, and chronic fatigue syndrome","volume":"17","author":"James","year":"2022","journal-title":"Neurosci. Insights"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4952","DOI":"10.1016\/j.vaccine.2017.07.076","article-title":"Correlation between anthrax lethal toxin neutralizing antibody levels and survival in guinea pigs and nonhuman primates vaccinated with the AV7909 anthrax vaccine candidate","volume":"35","author":"Savransky","year":"2017","journal-title":"Vaccine"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Ascough, S., Ingram, R.J., Chu, K.K.Y., Moore, S.J., Gallagher, T., Dyson, H., Doganay, M., Metan, G., Ozkul, Y., and Baillie, L. (2022). Impact of HLA polymorphism on the immune response to Bacillus anthracis protective antigen in vaccination versus natural infection. Vaccines, 10.","DOI":"10.3390\/vaccines10101571"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1016\/S0065-2776(08)60814-7","article-title":"Nature of retained antigen and its role in immune mechanisms","volume":"3","author":"Campbell","year":"1963","journal-title":"Adv. Immunol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"392","DOI":"10.1016\/j.humimm.2007.01.014","article-title":"Common and well-documented HLA alleles: Report of the ad-hoc committee of the American society for histocompatiblity and immunogenetics","volume":"68","author":"Cano","year":"2007","journal-title":"Hum. Immunol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"W449","DOI":"10.1093\/nar\/gkaa379","article-title":"NetMHCpan-4.1 and NetMHCIIpan-4.0: Improved predictions of MHC antigen presentation by concurrent motif deconvolution and integration of MS MHC eluted ligand data","volume":"48","author":"Reynisson","year":"2020","journal-title":"Nucleic Acids Res."},{"key":"ref_37","unstructured":"(2024, April 11). IEDB Analysis Resource. Available online: http:\/\/tools.iedb.org\/mhci\/."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1111\/tan.13956","article-title":"Binding affinities of 438 HLA proteins to complete proteomes of seven pandemic viruses and distributions of strongest and weakest HLA peptide binders in populations worldwide","volume":"96","author":"Barquera","year":"2020","journal-title":"HLA"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1016\/S0065-2776(01)77018-6","article-title":"The antiviral activity of antibodies in vitro and in vivo","volume":"77","author":"Parren","year":"2001","journal-title":"Adv. Immunol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"720","DOI":"10.1038\/s41577-023-00858-w","article-title":"Antiviral neutralizing antibodies: From in vitro to in vivo activity","volume":"23","author":"Burton","year":"2023","journal-title":"Nat. Rev. Immunol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1041","DOI":"10.1038\/ni1516","article-title":"Recent advances in antigen processing and presentation","volume":"8","author":"Jensen","year":"2007","journal-title":"Nat. Immunol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3209","DOI":"10.2174\/138161209789105162","article-title":"Prediction of MHC-peptide binding: A systematic and comprehensive overview","volume":"15","author":"Lafuente","year":"2009","journal-title":"Curr. Pharm. Des."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s00251-008-0341-z","article-title":"NetMHCpan, a method for MHC class I binding prediction beyond humans","volume":"61","author":"Hoof","year":"2009","journal-title":"Immunogenetics"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Wang, P., Sidney, J., Dow, C., Moth\u00e9, B., Sette, A., and Peters, B. (2008). A systematic assessment of MHC class II peptide binding predictions and evaluation of a consensus approach. PLoS Comput. Biol., 4.","DOI":"10.1371\/journal.pcbi.1000048"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Charonis, S.A., James, L.M., and Georgopoulos, A.P. (2022). SARS-CoV-2 in silico binding affinity to human leukocyte antigen (HLA) Class II molecules predicts vaccine effectiveness across variants of concern (VOC). Sci. Rep., 12.","DOI":"10.1038\/s41598-022-11956-5"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1007\/s00430-019-00577-x","article-title":"Development of a novel multiepitope chimeric vaccine against anthrax","volume":"208","author":"Aggarwal","year":"2019","journal-title":"Med. Microbiol. Immunol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"100574","DOI":"10.1016\/j.imu.2021.100574","article-title":"Immunoinformatic design of an epitope-based immunogen candidate against Bacillus anthracis","volume":"24","author":"Shamakh","year":"2021","journal-title":"Inform. Med. Unlocked"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1006\/biol.2001.0297","article-title":"The development of multi-epitope vaccines: Epitope identification, vaccine design and clinical evaluation","volume":"29","author":"Sette","year":"2001","journal-title":"Biologicals"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.meegid.2017.12.008","article-title":"Structural vaccinology considerations for in silico designing of a multi-epitope vaccine","volume":"58","author":"Negahdaripour","year":"2018","journal-title":"Infect. Genet. Evol."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Chauhan, V., Rungta, T., Goyal, K., and Singh, M.P. (2019). Designing a multi-epitope based vaccine to combat Kaposi Sarcoma utilizing immunoinformatics approach. Sci. Rep., 21.","DOI":"10.1038\/s41598-019-39299-8"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2191","DOI":"10.1007\/s10989-019-10013-6","article-title":"Immunoinformatics approach to engineer a potent poly-epitope fusion protein vaccine against Coxiella burnetii","volume":"26","author":"Rashidian","year":"2020","journal-title":"Int. J. Pept. Res. Ther."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1186\/s12859-022-04581-6","article-title":"In silico design of recombinant multi-epitope vaccine against influenza A virus","volume":"22","author":"Maleki","year":"2022","journal-title":"BMC Bioinform."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1080\/07391102.2020.1792347","article-title":"Designing a multi-epitope vaccine against SARS-CoV-2: An immunoinformatics approach","volume":"40","author":"Samad","year":"2022","journal-title":"J. Biomol. Struct. Dyn."},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Tan, C., Zhu, F., Pan, P., Wu, A., and Li, C. (2023). Development of multi-epitope vaccines against the monkeypox virus based on envelope proteins using immunoinformatics approaches. Front. Immunol., 14.","DOI":"10.3389\/fimmu.2023.1112816"},{"key":"ref_55","doi-asserted-by":"crossref","unstructured":"Mahanty, S., Prigent, A., and Garraud, O. (2015). Immunogenicity of infectious pathogens and vaccine antigens. BMC Immunol., 16.","DOI":"10.1186\/s12865-015-0095-y"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"13498","DOI":"10.1073\/pnas.1904170116","article-title":"Borrelia burgdorferi peptidoglycan is a persistent antigen in patients with Lyme arthritis","volume":"116","author":"Jutras","year":"2019","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1084\/jem.101.3.245","article-title":"Immunologic unresponsiveness induced by protein antigens","volume":"101","author":"Dixon","year":"1955","journal-title":"J. Exp. Med."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1111\/j.1365-2893.1997.tb00176.x","article-title":"Mechanisms of viral clearance and persistence","volume":"4","author":"Borrow","year":"1997","journal-title":"J. Viral Hepat."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"2039","DOI":"10.1128\/JVI.02167-06","article-title":"Persistent antigen presentation after acute vesicular stomatitis virus infection","volume":"81","author":"Turner","year":"2007","journal-title":"J. Virol."}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/13\/1\/88\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T10:31:15Z","timestamp":1759919475000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/13\/1\/88"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,1,18]]},"references-count":59,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,1]]}},"alternative-id":["vaccines13010088"],"URL":"https:\/\/doi.org\/10.3390\/vaccines13010088","relation":{},"ISSN":["2076-393X"],"issn-type":[{"type":"electronic","value":"2076-393X"}],"subject":[],"published":{"date-parts":[[2025,1,18]]}}}