RH tachyzoites, ME49 strain of T. gondii. ESP molecular weight (kDa)a Temp. (°C) 4   25   37   42
110     + +
97     + +
86     + (Tg386) +
80     + (Tg485) +
70 + + +  
60     + +
54 + + +  
42     + (Tg786) +
40     + +
36 + + + (Tg378)  
30 + + +  
28 + + + (Tg556)  
26 + + +  
22 + + +  
19 + + +  
aThe RH strain of T. gondii was maintained by peritoneal passages in Balb/c mice. For positive reference serum, mouse was infected with ME49 strain of the parasite for 8 weeks until the animal had brain cysts postmortem. The molecular mass of 15 ESP was estimated at 37°C. Among them,110, 97, 86, 80, 60, 42 and 40 kDa proteins were released temperature-dependently, while those of 70,54,36,30,28,26,22,and 19 kDa were released temperature-independently as low as 4°C. Five ESP of 86, 80, 42, 36 and 28 kDa reacted with monoclonal antibodies: Tg378 and Tg556 clones were detected 36 kDa and 28kDa proteins, respectively, in dense granules with involvement into parasitophorus vacuole, and these ESP were released regardless of temperature and time. Tg386 clone labeled presumably micronemal structure in tachyzoites, Tg485 clone labeled surface membrane protein; while Tg786 clone labeled probably rhoptry in the apical portion. ESP by Tg786 clone was released continuously with increment, whereas those by Tg378 and Tg556 clones were ceased to release after 3 and 4 hrs changes, respectively
Table 35: Profile of Excretory/Secretory Proteins (ESP) released from purified tachyzoites of T. gondii incubated for 1 hr at different temperatures and then analyzed by monoclonal antibodies (Son and Nam [575]; with own modification).