ABSTRACT
Immunization of BALB/c mice with an expression genomic library of Toxoplasma gondii induces a Th1-type immune response, with recognition of several T. gondii proteins (21 to 117 kDa) and long-term protective immunity against a lethal challenge. These results support further investigations to achieve a multicomponent anti-T. gondii DNA vaccine.
Subject(s)
Protozoan Vaccines/administration & dosage , Toxoplasma/immunology , Vaccines, DNA/pharmacology , Animals , Gene Expression , Genome, Protozoan , Genomic Library , Lymphocyte Activation , Male , Mice , Mice, Inbred BALB C , Protozoan Vaccines/genetics , Th1 Cells/immunology , Time Factors , Toxoplasma/genetics , Toxoplasmosis, Animal/immunology , Toxoplasmosis, Animal/prevention & control , Vaccination , Vaccines, DNA/geneticsABSTRACT
BALB/c mice were intramuscularly immunized with low doses (25-50microg) of DNA cocktail containing plasmids encoding the full-length SAG1/P30 and the 196-561 terminal sequence of ROP2 genes. This immunization resulted in a Th1-type response with predominance of IgG2a and a specific T-cell proliferation with high levels of interferon-gamma (IFN-gamma) secretion, whereas no IL-4 was detected. Moreover, DNA cocktail immunization induced a long-lasting protection against a lethal challenge with the highly virulent Toxoplasma gondii RH strain, whereas low doses of single genes were not protective. These results support further investigations to achieve a multigene anti-T. gondii DNA vaccine.
