Induction of protective immunity by DNA vaccination with Toxoplasma gondii HSP70, HSP30 and SAG1 genes

The vaccination with Toxoplasma gondii heat shock protein 70 (T.g.HSP70) gene (a virulent tachyzoite-specific) induced the most prominent reduction in T gondii loads in various organs of B6 and BALB/c mice at the acute and chronic phases of toxoplasmosis compared with T.g.HSP30 (a bradyzoite-specific) and SAG1(a tachyzoite-specific) genes. A single gene gun vaccination with 2 mug of T.g.HSP70 gene induced a significant reduction in the number of T gondii organisms compared with 50 mug of T.g.HSP70 gene vaccination by intramuscular (i.m.) or intraperitoneal (i.p.) injection. The vaccine effects of T.g.HSP70 gene persisted for more than 3 months. (C) 2003 Elsevier Science Ltd. All rights reserved.