Induction of protective Th1 immune responses in mice by vaccination with recombinant Toxoplasma gondii nucleoside triphosphate hydrolase-II

Vaccine. 2011 Feb 9. [Epub ahead of print]

Induction of protective Th1 immune responses in mice by vaccination with recombinant Toxoplasma gondii nucleoside triphosphate hydrolase-II

Tan F, Hu X, Luo FJ, Pan CW, Chen XG.

Department of Parasitology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, PR China; Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325035, PR China.

Abstract
The Toxoplasma gondii nucleoside triphosphate hydrolase (TgNTPase) has apyrase activity, degrading ATP to the di- and mono-phosphate forms and may be used by the parasite to salvage purines from the host cell for survival and replication. To study the immune-protective value of TgNTPase-II, BALB/c mice were immunized with a recombinant form of the antigen rTgNTPase-II combined with alum. All immunized mice produced specific anti-rTgNTPase-II immunoglobulins, with high IgG antibody titers and a mixed IgG1/IgG2a response, with predominance of IgG2a production. The cellular immune response was associated with the production of IFN-γ and IL-2 cytokines and the increase of the percentage of CD8+ T cells. Vaccinated mice displayed significant protection against acute infection with the virulent RH strain (P<0.05 in survival rate) and also chronic infection with PRU cyst (62.9% and 57.6% reduction in brain parasite load for rTgNTPase-II+alum and rTgNTPase-II alone vaccinated groups) compared to the non-vaccinated control group. In conclusion, rTgNTPase-II elicits a strong specific Th1 immune response providing partial protection against both T. gondii acute and chronic infection.

Copyright © 2011. Published by Elsevier Ltd.
PMID: 21315696 [PubMed - as supplied by publisher]