{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,3]],"date-time":"2026-11-03T18:43:29Z","timestamp":1793731409430,"version":"4.6.1"},"reference-count":41,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2024,4,24]],"date-time":"2024-04-24T00:00:00Z","timestamp":1713916800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100005825","name":"National Institute of Food and Agriculture","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100005825","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000193","name":"International Development Research Centre","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000193","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p><jats:italic>Babesia bovis<\/jats:italic>, a tick-borne apicomplexan parasite causing bovine babesiosis, remains a significant threat worldwide, and improved and practical vaccines are needed. Previous studies defined the members of the rhoptry associated protein-1 (RAP-1), and the neutralization-sensitive rhoptry associated protein-1 related antigen (RRA) superfamily in <jats:italic>B. bovis<\/jats:italic>, as strong candidates for the development of subunit vaccines. Both RAP-1 and RRA share conservation of a group of 4 cysteines and amino acids motifs at the amino terminal end (NT) of these proteins.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods and results<\/jats:title><jats:p>Sequence comparisons among the RRA sequences of several <jats:italic>B. bovis<\/jats:italic> strains and other <jats:italic>Babesia<\/jats:italic> spp parasites indicate a high level of conservation of a 15-amino acid (15-mer) motif located at the NT of the protein. BlastP searches indicate that the 15-mer motif is also present in adenylate cyclase, dynein, and other ATP binding proteins. AlphaFold2 structure predictions suggest partial exposure of the 15-mer on the surface of RRA of three distinct <jats:italic>Babesia<\/jats:italic> species. Antibodies in protected cattle recognize a synthetic peptide representing the 15-mer motif sequence in iELISA, and rabbit antibodies against the 15-mer react with the surface of free merozoites in immunofluorescence.<\/jats:p><\/jats:sec><jats:sec><jats:title>Discussion and conclusion<\/jats:title><jats:p>The presence of the 15-mer-like regions in dynein and ATP-binding proteins provides a rationale for investigating possible functional roles for RRA. The demonstrated presence of a surface exposed B-cell epitope in the 15-mer motif of the <jats:italic>B. bovis<\/jats:italic> RRA, which is recognized by sera from protected bovines, supports its inclusion in future subunit epitope-based vaccines against <jats:italic>B. bovis<\/jats:italic>.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fimmu.2024.1380660","type":"journal-article","created":{"date-parts":[[2024,4,24]],"date-time":"2024-04-24T04:43:13Z","timestamp":1713933793000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["A conserved motif in the immune-subdominant RAP-1 related antigen of Babesia bovis contains a B-cell epitope recognized by antibodies from protected cattle"],"prefix":"10.3389","volume":"15","author":[{"given":"Manuel J.","family":"Rojas","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Reginaldo G.","family":"Bastos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinna","family":"Navas","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jacob M.","family":"Laughery","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul A.","family":"Lacy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlos E.","family":"Suarez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2024,4,24]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vetpar.2011.05.032","article-title":"Emerging perspectives in the research of bovine babesiosis and anaplasmosis","volume":"180","author":"Suarez","year":"2011","journal-title":"Vet Parasitol"},{"key":"B2","doi-asserted-by":"publisher","first-page":"274","DOI":"10.1186\/s13071-023-05885-z","article-title":"Exploring the landscape of Babesia bovis vaccines: progress, challenges, and opportunities","volume":"16","author":"Santos","year":"2023","journal-title":"Parasit Vectors"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1016\/j.pt.2021.04.011","article-title":"Unraveling the elusive rhoptry exocytic mechanism of apicomplexa","volume":"37","author":"Sparvoli","year":"2021","journal-title":"Trends Parasitol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0007680","article-title":"Montero Comparative and functional genomics of the protozoan parasite Babesia divergens highlighting the invasion and egress processes","volume":"13","author":"Gonz\u00e1lez","year":"2019","journal-title":"E.PLoS Negl Trop Dis"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1016\/j.pt.2019.01.007","article-title":"Babesia life cycle\u2014when phylogeny meets biology","volume":"35","author":"Jalovecka","year":"2019","journal-title":"Trends Parasitol"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0035227","article-title":"Gliding motility of Babesia bovis merozoites visualized by time-lapse video microscopy","volume":"7","author":"Asada","year":"2012","journal-title":"PloS One"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1016\/j.exppara.2006.11.006","article-title":"Babesia bovis: subcellular localization of host erythrocyte membrane components during their asexual growth","volume":"116","author":"Okamura","year":"2007","journal-title":"Exp Parasitol"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.7717\/peerj.11765","article-title":"Sthitmatee N.Structural and immunological characterization of an epitope within the PAN motif of ectodomain I in Babesia bovis apical membrane antigen 1 for vaccine development","volume":"9","author":"Rittipornlertrak","year":"2021","journal-title":"PeerJ."},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1016\/s0169-4758(99)01471-4","article-title":"Palmer GH Designing blood-stage vaccines against Babesia bovis and B","volume":"15","author":"Brown","year":"1999","journal-title":"bigemina. 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