The role of various proteins of Toxoplasma gondii in provoking immune response at different stages of infection

Abstract

Toxoplasma gondii is the causative protozoan of toxoplasmosis which has a worldwide distribution among humans and warm-blooded animals. The diagnosis generally depends on serologic tests but the persistently high Immunoglobulin M (IgM) or low IgG avidity complicate diagnosis. It is essential to identify acute-stage-specific antigen to use in a single test for the definitive diagnosis of the acute disease, especially in pregnant women and immunocompromised individuals. In this study, we investigated the recognition of proteins of lysate antigen (LA) and excretory-secretory antigen (ESA) fractions of the virulent RH strain of T. gondii by the sera of patients who had recent or past infections and the sera of experimentally infected mice. As a result, no specific bands for discrimination of recent infection from the past one could be detected in our study but the results confirmed that proteins of approximately 20, 30 and 40 kDa were among the major targets for IgG responses during acute and chronic infection with T. gondii in humans.

Cloning and Sequencing of Truncated Toxoplasma gondii Subtilisin-Like 1 Antigen

“…After three to four days post infection peritoneal cavities of the animals were washed with 5 mL of cooled and sterile phosphate-buffered saline (PBS) containing streptomycin and penicillin and collected exudate was centrifuged at 50 xg for 5 minutes to remove host cells. Then supernatant was washed and centrifuged twice at 1000 xg for 10 minutes, and the tachyzoites were collected [3] and pelleted tachyzoites immediately dissolved in RLT buffer containing 2-ME (Qiagen, Germany) and kept at -80°C until RNA extraction.…”

“…In animals, the disease makes economic losses by embryonic death and resorption, fetal death and mummification, abortion, stillbirth, and neonatal death. The parasite is mainly transmitted by food or water contaminated by sporulated oocysts in the faeces of infected felids as definitive hosts; by consumption of raw or undercooked meat containing the bradyzoite in tissue cysts and by transplacental transmission [3][4][5].…”