Screening and identification of protective antigens are essential for the prevention of infections with Toxoplasma gondii (Nicolle et Manceaux, 1908). In our previous study, T. gondii ribosomal-ubiquitin protein L40 (TgRPL40) was identified as a circulating antigen. However, the function and protective value of TgRPL40 was unknown. In the current study, recombinant TgRPL40 was expressed in Escherichia coli BL21 and antibody was prepared. Western blotting analysis indicated that TgRPL40 was present in circulating antigens and excretory/secretary antigens (ESA). Immunofluorescence and immunoelectron microscopy analysis revealed that TgRPL40 protein is widely distributed in the tachyzoites. Immunisation with recombinant TgRPL40 prolonged the survival of mice infected with tachyzoites. Quantitative real-time polymerase chain reaction analysis showed that immunisation with recombinant TgRPL40 reduced the parasite burden in blood, liver, spleen and brain of mice infected with tachyzoites. These observations indicate that TgRPL40 is a circulating antigen and is an effector of immune protection against acute T. gondii infection.
Toxoplasmosis is caused by intracellular protozoan parasite, Toxoplasma gondii (Nicolle et Manceaux, 1908). Cats and other felids are the definitive hosts. It could be transmitted to man and animals by consumption of infected undercooked meat and contaminated food items including drinking water. Results of toxoplasmosis epidemiological surveys in animals and humans in South-West, North-West, North-East and North-Central Zones of Nigeria have been reported with greater impact on the health of pregnant women and HIV-infected individuals. Meanwhile, studies in states within the South-South and South-East Zones are relatively scanty or non-existent. Overall, the seroprevalence of human toxoplasmosis in Nigeria is estimated at 32% with the following reports for North-West (32%), North-East (22%), North-Central (24%) and South-West (37%). Information on the genetic diversity of isolates of T. gondii in humans and animals including the role of the environment in transmission and maintenance of the disease are highly needed., John Asekhaen Ohiolei, Clement Isaac., and Obsahuje bibliografii