Enhancement of protective immune responses induced by Toxoplasma gondii dense granule antigen 7 (GRA7) against toxoplasmosis in mice using a prime-boost vaccination strategy.
Effective vaccines against Toxoplasma gondii may contribute to preventing and controlling the spread of toxoplasmosis, which is important for improving outcomes of infections in humans and livestock animals. The dense granule antigen 7 (GRA7) of T. gondii might be an immunodominant antigen for a vaccine candidate. In the present study, a further exploration of its vaccine effect, a heterologous prime-boost vaccination strategy with a recombinant eukaryotic plasmid pEGFP-GRA7 and a recombinant protein GRA7 expressed from a prokaryotic plasmid pET30-GRA7, was performed in BALB/c mice. The data reveal that a DNA prime-protein boost vaccination induces both humoral and cellular immune responses against T. gondii associated with high levels of total IgG, IgG2a isotype and gamma interferon (IFN-γ). Challenge experiments further show that the DNA prime-protein boost vaccination significantly increases survival rate (60%), compared with controls in which all died within 8 days of challenge. Therefore, the DNA prime-protein boost vaccination based on GRA7 might be a promising regimen for further development of an effective vaccine against T. gondii.
Department of Parasitology, Shandong University School of Medicine, Jinan, Shandong 250012, PR China.
Juan
J
Min
Daofeng
D
Qu
Changzheng
C
Li
Xilin
X
Song
Qunli
Q
Zhao
Xin-ai
XA
Li
Yongmei
Y
Yang
Qi
Q
Liu
Shenyi
S
He
Huaiyu
H
Zhou
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D015800:Protozoan Proteins / Q000008:administration & dosage / Q000276:immunology*; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000276:immunology*; D016019:Survival Analysis; D014124:Toxoplasmosis, Animal / Q000517:prevention & control*; D014611:Vaccination / Q000379:methods*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C112573:GRA7 protein, Toxoplasma gondii; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D019444:Vaccines, DNA; D022223:Vaccines, Subunit; D014614:Vaccines, Synthetic; D007371:Interferon-gamma