title: Protective immune response against Toxoplasma gondii elicited by a recombinant DNA vaccine with a novel genetic adjuvant.
abstract: Previous immunological studies from our laboratory have demonstrated the potential role of Toxoplasma gondii antigens SAG1 and GRA2 as vaccine candidates. To further evaluate the vaccine's effects, a series of recombinant DNA vaccines pVAX1-SAG1, pVAX1-GRA2 and pVAX1-SAG1-GRA2, termed pSAG1, pGRA2 and pSAG1-GRA2, respectively, were constructed. A plasmid pVAX1-S/PreS2, termed pSPreS2 encoding hepatitis B virus (HBV) surface antigen (HBsAg) S and PreS2 as a novel genetic adjuvant, was also constructed. The expression abilities of those DNA plasmids were examined in HFF cells by Western blotting. Then BALB/c mice were intramuscularly immunized with DNA plasmids and followed by challenging with the highly virulent T. gondii RH strain. The results demonstrated that the recombinant DNA vaccine pSAG1-GRA2 was capable of eliciting high levels of antibodies, a Th1 type of immune response with significant production of IFN-γ and low levels of IL-4 or IL-10 in BALB/c mice, and partial protection against the acute phase of toxoplasmosis as compared to pSAG1, pGRA2 and controls. In addition, the adjuvant pSPreS2 formulated with DNA vaccine induced a Th1 type of immune response and therefore might be a novel genetic adjuvant to DNA vaccine for further investigation.
authors.affiliation: Department of Parasitology, Shandong University School of Medicine, Jinan, Shandong, PR China. zhouhy@sdu.edu.cn
authors.forename: Huaiyu
authors.initials: H
authors.lastname: Zhou
authors.forename: Juan
authors.initials: J
authors.lastname: Min
authors.forename: Qunli
authors.initials: Q
authors.lastname: Zhao
authors.forename: Qinmin
authors.initials: Q
authors.lastname: Gu
authors.forename: Hua
authors.initials: H
authors.lastname: Cong
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Shenyi
authors.initials: S
authors.lastname: He
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology*; D002478:Cells, Cultured; D005260:Female; D006514:Hepatitis B Surface Antigens / Q000008:administration & dosage; D006801:Humans; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000276:immunology; D015800:Protozoan Proteins / Q000276:immunology*; D016052:Protozoan Vaccines / Q000235:genetics / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology; D014123:Toxoplasmosis / Q000276:immunology / Q000517:prevention & control*; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C106990:Gra2 protein, Toxoplasma gondii; D006514:Hepatitis B Surface Antigens; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; C047168:SAG1 antigen, Toxoplasma; D019444:Vaccines, DNA; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma