Vaccine potential of a tick vitellin-degrading enzyme (VTDCE)

Vet Immunol Immunopathol. 2008 Aug 15;124(3-4):332-40. doi: 10.1016/j.vetimm.2008.04.001. Epub 2008 Apr 16.

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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / blood
  • Aspartic Acid Endopeptidases / immunology
  • Blotting, Western / veterinary
  • Cattle
  • Cattle Diseases / immunology
  • Cattle Diseases / parasitology*
  • Cattle Diseases / prevention & control
  • Cysteine Endopeptidases / immunology*
  • Cysteine Endopeptidases / metabolism
  • Enzyme Precursors / immunology
  • Enzyme-Linked Immunosorbent Assay / veterinary
  • Female
  • Rhipicephalus / immunology*
  • Tick Infestations / immunology
  • Tick Infestations / prevention & control
  • Tick Infestations / veterinary*
  • Vaccines / immunology*
  • Vaccines / pharmacology
  • Vitellins / metabolism

Substances

  • Antibodies
  • Enzyme Precursors
  • Vaccines
  • Vitellins
  • Cysteine Endopeptidases
  • Aspartic Acid Endopeptidases
  • Boophilus yolk pro-cathepsin