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Experimental vaccination of sheep and cattle against tick infestation using recombinant 5'-nucleotidase.

Hope M, Jiang X, Gough J, Cadogan L, Josh P, Jonsson N, Willadsen P - Parasite Immunol. (2010)

Bottom Line: Although Bm86 showed typical efficacy, no significant protection was seen in cattle vaccinated with 5'-nucleotidase.Cattle receiving a dual antigen formulation were no better protected than those receiving Bm86 alone.This demonstrates a limitation of using a model host like sheep in vaccine studies.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Livestock Industries, St Lucia, Queensland, Australia.

ABSTRACT
Limited prior evidence suggests that 5'-nucleotidase, an ectoenzyme principally located in the Malpighian tubules of the tick Rhipicephalus (Boophilus) microplus, could be an effective antigen in an anti-tick vaccine. To assess this, recombinant 5'-nucleotidase was expressed in Escherichia coli and used in vaccination trials with both sheep and cattle. Vaccinated sheep were challenged with freshly moulted adult ticks. Those with high titres of anti-nucleotidase antibodies showed significant protection against tick infestation, although protection was less than that found with the previously characterized antigen, Bm86. Cattle were vaccinated, in separate groups, with 5'-nucleotidase, Bm86 and both antigens combined. Cattle, as the natural host, were challenged with larval ticks. Although Bm86 showed typical efficacy, no significant protection was seen in cattle vaccinated with 5'-nucleotidase. Cattle receiving a dual antigen formulation were no better protected than those receiving Bm86 alone. One possible reason for the difference between host species, namely antibody titre, was examined and shown to be an unlikely explanation. This demonstrates a limitation of using a model host like sheep in vaccine studies.

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Related in: MedlinePlus

Correlation of the antibody titre to 5′-nucleotidase with the mass of eggs laid per 10 female ticks attached to sheep after 24 h.
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fig01: Correlation of the antibody titre to 5′-nucleotidase with the mass of eggs laid per 10 female ticks attached to sheep after 24 h.

Mentions: The effect of vaccination with Bm86 was significant for all parameters (P< 0·01) with both adjuvants separately and as a combined group. For the group vaccinated with 5′-nucleotidase, the effect of adjuvant was significant for percentage engorgement (P< 0·01), fecundity (P< 0·05) and reproductive potential (P< 0·01). Despite the small animal numbers, the effects of 5′-nucleotidase were significant when ISA50 was used as adjuvant. In neither the group vaccinated using ISA773 nor in the combined group was the effect on ticks significant. The likely explanation is the differences in antibody titre. The probable importance of circulating antibody level was reinforced by examination of the correlations between the parasite parameters and log10 antibody titre for all sheep (Figure 1). All correlations were statistically significant (P< 0·01).


Experimental vaccination of sheep and cattle against tick infestation using recombinant 5'-nucleotidase.

Hope M, Jiang X, Gough J, Cadogan L, Josh P, Jonsson N, Willadsen P - Parasite Immunol. (2010)

Correlation of the antibody titre to 5′-nucleotidase with the mass of eggs laid per 10 female ticks attached to sheep after 24 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2821529&req=5

fig01: Correlation of the antibody titre to 5′-nucleotidase with the mass of eggs laid per 10 female ticks attached to sheep after 24 h.
Mentions: The effect of vaccination with Bm86 was significant for all parameters (P< 0·01) with both adjuvants separately and as a combined group. For the group vaccinated with 5′-nucleotidase, the effect of adjuvant was significant for percentage engorgement (P< 0·01), fecundity (P< 0·05) and reproductive potential (P< 0·01). Despite the small animal numbers, the effects of 5′-nucleotidase were significant when ISA50 was used as adjuvant. In neither the group vaccinated using ISA773 nor in the combined group was the effect on ticks significant. The likely explanation is the differences in antibody titre. The probable importance of circulating antibody level was reinforced by examination of the correlations between the parasite parameters and log10 antibody titre for all sheep (Figure 1). All correlations were statistically significant (P< 0·01).

Bottom Line: Although Bm86 showed typical efficacy, no significant protection was seen in cattle vaccinated with 5'-nucleotidase.Cattle receiving a dual antigen formulation were no better protected than those receiving Bm86 alone.This demonstrates a limitation of using a model host like sheep in vaccine studies.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Livestock Industries, St Lucia, Queensland, Australia.

ABSTRACT
Limited prior evidence suggests that 5'-nucleotidase, an ectoenzyme principally located in the Malpighian tubules of the tick Rhipicephalus (Boophilus) microplus, could be an effective antigen in an anti-tick vaccine. To assess this, recombinant 5'-nucleotidase was expressed in Escherichia coli and used in vaccination trials with both sheep and cattle. Vaccinated sheep were challenged with freshly moulted adult ticks. Those with high titres of anti-nucleotidase antibodies showed significant protection against tick infestation, although protection was less than that found with the previously characterized antigen, Bm86. Cattle were vaccinated, in separate groups, with 5'-nucleotidase, Bm86 and both antigens combined. Cattle, as the natural host, were challenged with larval ticks. Although Bm86 showed typical efficacy, no significant protection was seen in cattle vaccinated with 5'-nucleotidase. Cattle receiving a dual antigen formulation were no better protected than those receiving Bm86 alone. One possible reason for the difference between host species, namely antibody titre, was examined and shown to be an unlikely explanation. This demonstrates a limitation of using a model host like sheep in vaccine studies.

Show MeSH
Related in: MedlinePlus