Induction of protective immunity by multiantigenic DNA vaccine delivered in attenuated Salmonella typhimurium against Toxoplasma gondii infection

Vet Parasitol. 2009 Aug 21. [Epub ahead of print]

Induction of protective immunity by multiantigenic DNA vaccine delivered in attenuated Salmonella typhimurium against Toxoplasma gondii infection in mice

Qu D, Yu H, Wang S, Cai W, Du A.

Key Laboratory of Animal Epidemic Etiology and Immunological Prevention of Ministry of Agriculture, Zhejiang University, Hangzhou 310029, China; Institute of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China.

Toxoplasma gondii, capable of infecting all warm blooded animals, is one of the most successful parasites worldwide. It was reported that the single-gene vaccine with SAG1 or MIC3 could only produce partial protection against T. gondii and multiantigenic vaccines were more effective than single ones. In the present study, a multiantigenic DNA vaccine delivered by attenuated Salmonella typhimurium (ZJ111/pSAG1-MIC3) was constructed, which expresses surface protein SAG1 and micronemal protein MIC3. The safety and stability of ZJ111/pSAG1-MIC3 were evaluated and immune response with ZJ111/pSAG1 and ZJ111/pMIC3 were compared. The results of lymphocyte proliferation assay, antibody and cytokine determination show that mice immunized with ZJ111/pSAG1-MIC3 elicited stronger humoral and Th1-type cellular immune responses than other groups. The mice immunized with ZJ111/pSAG1-MIC3 also exhibited significant higher survival time after challenged with T. gondii RH strain. The current study shows that the oral multiantigenic DNA vaccine, ZJ111/pSAG1-MIC3, produces partial protection against T. gondii challenge.

PMID: 19740610 [PubMed - as supplied by publisher]