Characterization of secreted recombinant Toxoplasma gondii surface antigen 2 (SAG2) heterologously expressed by the yeast Pichia pastoris.
The surface antigen 2 (SAG2) gene of the protozoan parasite, Toxoplasma gondii, was cloned and extracellularly expressed in the yeast Pichia pastoris. The effectiveness of the secreted recombinant SAG2 (rSAG2-S) as a serodiagnosis reagent was assessed by western blots and ELISA. In the western blot assay, rSAG2-S reacted with all Toxoplasma-antibody positive human serum samples but not with Toxoplasma-negative samples. In the ELISA, rSAG2-S yielded sensitivity rates ranging from 80% (IgG negative, IgM positive) to 100% (IgG positive, IgM negative). In vivo experiments showed that serum from mice immunized with rSAG2-S reacted specifically with the native SAG2 of T. gondii. These mice were protected when challenged with live cells of T. gondii.
Fong
Mun Yik
MY
Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia. fongmy@um.edu.my
Lau
Yee Ling
YL
Zulqarnain
Mohamed
M
D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D051379:Mice; D008813:Mice, Inbred ICR; D010843:Pichia / Q000235:genetics*; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism*; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C067547:surface antigen P22, Toxoplasma