Korean J Parasitol.  2001 Sep;39(3):233-240. 10.3347/kjp.2001.39.3.233.

Effects of specific monoclonal antibodies to dense granular proteins on the invasion of Toxoplasma gondii in vitro and in vivo

• Cha DY
• Song IK
• Lee GS
• Hwang OS
• Noh HJ
• Yeo SD
• Shin DW
• Lee YH

• KMID: 1039174
• DOI: http://doi.org/10.3347/kjp.2001.39.3.233

Abstract

Although some reports have been published on the protective effect of antibodies to Toxoplasma gondii surface membrane proteins, few address the inhibitory activity of antibodies to dense granular proteins (GRA proteins). Therefore, we performed a series of experiments to evaluate the inhibitory effects of monoclonal antibodies (mAbs) to GRA proteins (GRA2, 28 kDa; GRA6, 32 kDa) and surface membrane protein (SAG1, 30 kDa) on the invasion of T. gondii tachyzoites. Passive immunization of mice with one of three mAbs following challenge with a lethal dose of tachyzoites significantly increased survival compared with results for mice treated with control ascites. The survival times of mice challenged with tachyzoites pretreated with anti-GRA6 or anti-SAG1 mAb were significantly increased. Mice that received tachyzoites pretreated with both mAb and complement had longer survival times than those that received tachyzoites pretreated with mAb alone. Invasion of tachyzoites into fibroblasts and macrophages was significantly inhibited in the anti-GRA2, anti-GRA6 or anti-SAG1 mAb pretreated group. Pretreatment with mAb and complement inhibited invasion of tachyzoites in both fibroblasts and macrophages. These results suggest that specific antibodies to dense-granule molecules may be useful for controlling infection with T. gondii.

MeSH Terms

Animals
Antibodies, Monoclonal/*pharmacology/therapeutic use
*Antigens, Protozoan
Female
Fibroblasts/parasitology
Host-Parasite Relations
Immunization, Passive
Macrophages/parasitology
Mice
Mice, Inbred BALB C
Protozoan Proteins/*immunology
Support, Non-U.S. Gov't
Toxoplasma/*pathogenicity
Toxoplasmosis/parasitology/*therapy