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Protection studies with recombinant excretory/secretory proteins of Haemonchus contortus
Author(s) -
Vervelde L.,
Van Leeuwen M. A. W.,
Kruidenier M.,
Kooyman F. N. J.,
Huntley J. F.,
Van Die I.,
Cornelissen A. W. C. A.
Publication year - 2002
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1046/j.1365-3024.2002.00454.x
Subject(s) - haemonchus contortus , biology , recombinant dna , immunology , antibody , immunoglobulin e , glycan , vaccination , immunoglobulin a , mast cell , helminths , immunoglobulin g , glycoprotein , microbiology and biotechnology , biochemistry , gene
Summary 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.