title: Vaccine potential of a tick vitellin-degrading enzyme (VTDCE).
abstract: VTDCE (Vitelin-Degrading Cysteine Endopeptidase) is a peptidase with an active role in Rhipicephalus (Boophilus) microplus embryogenesis. VTDCE is found in the tick's eggs and was shown to be the most active protein in vitellin (VT) hydrolysis of the three peptidases already characterized in R. microplus eggs (Boophilus Yolk pro-cathepsin (BYC), Tick Heme Binding Aspartic Proteinase (THAP) and VTDCE). VTDCE activity was assessed in vitro using the natural substrate and a synthetic substrate (N-Cbz-Phe-Arg-MCA). The activity was inhibited by anti-VTDCE antibodies. In the present study, it was shown that VTDCE acts differently from BYC and THAP in VT hydrolysis and that the vaccination of bovines with VTDCE induces a partial protective immune response against R. microplus infestation. Immunized bovines challenged with R. microplus larvae presented an overall protection of 21%, and a reduction in the weight of fertile eggs of 17.6% was observed. The data obtained indicate that VTDCE seems to be important for tick physiology, and that it induces partial protective immune response when inoculated in bovines. This suggests that VTDCE can be useful to improve the protective capacity observed for other antigens.
authors.affiliation: Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, 9500 Prédio 43421, Porto Alegre, RS 91501-970, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Seixas
authors.forename: Alexandre T
authors.initials: AT
authors.lastname: Leal
authors.forename: Maria Clara L
authors.initials: MC
authors.lastname: Nascimento-Silva
authors.forename: Aoi
authors.initials: A
authors.lastname: Masuda
authors.forename: Carlos
authors.initials: C
authors.lastname: Termignoni
authors.forename: Itabajara
authors.initials: I
authors.lastname: da Silva Vaz
mesh_terms: D000818:Animals; D000906:Antibodies / Q000097:blood; D016282:Aspartic Acid Endopeptidases / Q000276:immunology; D015153:Blotting, Western / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000469:parasitology* / Q000517:prevention & control; D003546:Cysteine Endopeptidases / Q000276:immunology* / Q000378:metabolism; D004792:Enzyme Precursors / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D048494:Rhipicephalus / Q000276:immunology*; D013984:Tick Infestations / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D014612:Vaccines / Q000276:immunology* / Q000494:pharmacology; D047048:Vitellins / Q000378:metabolism
chemical_list: D000906:Antibodies; D004792:Enzyme Precursors; D014612:Vaccines; D047048:Vitellins; D003546:Cysteine Endopeptidases; D016282:Aspartic Acid Endopeptidases; C113293:Boophilus yolk pro-cathepsin