Attempts to immunize sheep against Haemonchus contortus using a cocktail of recombinant proteases derived from the protective antigen, H‐gal‐GP

@article{Cachat2010AttemptsTI,
  title={Attempts to immunize sheep against Haemonchus contortus using a cocktail of recombinant proteases derived from the protective antigen, H‐gal‐GP},
  author={{\'E}lise Cachat and George F J Newlands and S E Ekoja and Hudson McAllister and W. David Smith},
  journal={Parasite Immunology},
  year={2010},
  volume={32}
}
The objective of this study was to determine whether an antigen cocktail containing recombinantly expressed versions of most of the protective proteases of H‐gal‐GP, a known protective antigen from Haemonchus contortus, would confer any protection to lambs in a vaccine‐challenge trial. Haemonchus contortus metalloendopeptidases, MEP1, MEP3 and MEP4, were expressed as soluble recombinant proteins in insect cells, but attempts to express the H. contortus aspartyl proteases, PEP1 and PEP2, by the… 

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References

SHOWING 1-10 OF 16 REFERENCES

Metalloendopeptidases from the intestinal brush border of Haemonchus contortus as protective antigens for sheep

There was no significant protection when sheep were immunized with fully reduced and denatured H‐gal‐GP or with bacterially expressed recombinant forms of MEP 1 or the principal domains of MEP3, suggesting that conformational epitopes on the MEPs are required for immunity.

Further immunization and biochemical studies with a protective antigen complex from the microvillar membrane of the intestine of Haemonchus contortus

It is hypothesized that H‐gal‐GP is a gut membrane associated multiprotease complex which is involved in the digestion of the blood meal and which can be neutralized by specific antibodies with drastic consequences for the parasite.

Progress and new technologies for developing vaccines against gastrointestinal nematode parasites of sheep

An overview of the current explosion in new high‐throughput technologies, arising from human studies, for analysis of the genome, transcriptome, proteome and glycome offers the opportunity to gain a better understanding of the molecular pathways underlying pathogen biology, the host immune system and the host–pathogen interaction.

Molecular characterization of a family of metalloendopeptidases from the intestinal brush border of Haemonchus contortus

Proteomic analysis of the MEP fraction of the H-gal-GP indicated that the extracellular domain of all 4 MEPs had been cleaved close to the transmembrane region/signal peptide with additional cleavage sites mid-way along the polypeptide, suggesting each MEP might have a different substrate specificity.

Vaccination with Recombinant Aspartic Hemoglobinase Reduces Parasite Load and Blood Loss after Hookworm Infection in Dogs

This is the first report of a recombinant vaccine from a hematophagous parasite that significantly reduces both parasite load and blood loss, and it supports the development of APR-1 as a human hookworm vaccine.

Hookworm aspartic protease, Na-APR-2, cleaves human hemoglobin and serum proteins in a host-specific fashion.

The cloning and functional expression of an aspartic protease, Na-APR-2, from the human hookworm Necator americanus are described here, and the term "nemepsins" for members of this family of nematode-specific hydrolases is proposed.

A Multi-enzyme Cascade of Hemoglobin Proteolysis in the Intestine of Blood-feeding Hookworms*

The semi-ordered pathway of Hb digestion described here is surprisingly similar to that used by Plasmodium to digest Hb and provides a potential mechanism by which these hemoglobinases are efficacious vaccines in animal models of hookworm infection.