Submitted to: Infection and Immunity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 10, 2004
Publication Date: March 5, 2004
Citation: Jenkins, M.C., Parker, C.C., Tuo, W., Vinyard, B., Dubey, J.P. 2004. Inclusion of cpg adjuvant with plasmid dna coding for ncgra7 improves protection against congenital neosporosis. Infection and Immunity. 72:1817-1819.
Interpretive Summary: The disease neosporosis is a major cause of abortion in dairy cattle worldwide. Abortion occurs by congenital infection of the fetus by Neospora caninum tachyzoites during early-mid gestation. Research has shown that immunization of cows with a whole protein extract of N. caninum tachyzoites can prevent neosporosis-associated abortion. A desired vaccine would utilize specific antigens of the parasite that could be produced in large quantities in simple bacteria such as Escherichia coli. The present study showed that immunization of mice with a single N. caninum antigen in the presence of an adjuvant elicited nearly complete protection against congenital infection. While the level of protection was high with antigen alone, the addition of adjuvant increased the protective immunity by two-fold. These results indicate that it is possible to prevent congenital neosporosis in pregnant mice by immunization with a single N. caninum antigen, but that an adjuvant may be needed to stimulate higher levels of immunity. These findings provide a basis for vaccination trials in ruminants such as sheep and dairy cattle.
The present study showed that incorporating CpG adjuvant into plasmid DNA coding for NcGRA7 antigen resulted in a two-fold increase in the level of protection against congenital transfer of Neospora caninum. The level of protection was considerably higher than that observed in pups born from dams immunized with non-recombinant plasmid.