Protection studies with recombinant excretory/secretory proteins of Haemonchus contortus

L Vervelde*, MAW van Leeuwen, M Kruidenier, FNJ Kooyman, JF Huntley, Irma van Die, AWCA Cornelissen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

The efficacy of two recombinant proteins of Haemonchus contortus was studied in both adult sheep and young lambs. These 15 and 24 kDa excretory/secretory proteins were given combined, either supplemented or not with a glycan-rich insect cell extract. In 9-month-old sheep (trial 1), faecal egg output and worm burden were reduced by 49% and 55%, respectively, after vaccination with rec15/24, and by 46% and 65% after vaccination with rec15/24 and glycan extract. No reduction in egg output or number of worms was found in young lambs using the above recombinant proteins plus glycan-rich extract (trial 2). When trial 1 was repeated (trial 3), the protection could not be reproduced, possibly due to differences in batches of recombinant proteins. In all sheep, independent of their age, rec15/24-specific immunoglobulin (Ig)G1 and IgA titres were present, but 9-month-old protected sheep had significantly higher IgA titres than the lambs. Addition of glycans resulted in lower rec15/24-specific IgG1 and IgA in 9-month-old sheep after challenge. This did not affect the level of protection. A significant negative correlation was found between IgA and worm numbers in protected sheep immunized with rec15/24 supplemented with glycans. Total IgE and rec15/24 specific IgE titres were low. The number of eosinophils, mast cells, sheep mast cell protease (SMCP)+ cells and IgA+ cells did not differ between the protected and unprotected sheep, but the lambs had significantly fewer mast cells independent of their immunization.

Original languageEnglish
Pages (from-to)189-201
Number of pages13
JournalParasite Immunology
Volume24
Issue number4
DOIs
Publication statusPublished - Apr 2002

Keywords

  • IMMUNITY
  • EXCRETORY-SECRETORY PROTEINS
  • INFECTED SHEEP
  • RESPONSES
  • CARBOHYDRATE CHAINS
  • IGE
  • Haemonchus contortus
  • vaccination
  • GASTROINTESTINAL NEMATODE PARASITES
  • N-LINKED OLIGOSACCHARIDES
  • VACCINATION
  • VENOM PHOSPHOLIPASE-A2
  • carbohydrates
  • immune response

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