Reactivation of chronic infection with Toxoplasma gondii can cause life-threatening toxoplasmic encephalitis in immunocompromised individuals. We examined the role of VCAM-1/α4β1 integrin interaction in T cell recruitment to prevent reactivation of the infection in the brain. SCID mice were infected and treated with sulfadiazine to establish a chronic infection. VCAM-1 and ICAM-1 were the endot...

Within its intermediate host, Toxoplasma gondii switches between two forms: a rapidly replicating tachyzoite and an encysted bradyzoite. Bradyzoites persist within the host throughout its life, hidden from antimicrobial agents and the immune system. The signals that mediate switching are poorly understood. A gene trap was employed to isolate genes whose expression is up-regulated early in the s...

CD8 T cells are important for maintaining the chronicity of Toxoplasma gondii infection. In a T. gondii encephalitis susceptible model, we recently demonstrated that CD4 T cells play an essential helper role in the maintenance of the effector response and CD8 T cell dysfunctionality was linked to CD4 T cell exhaustion. However, CD4 T cells are constituted of different subsets with various funct...

To determine the genotypes of Toxoplasma gondii strains associated with human toxoplasmosis, we developed a sensitive approach for typing parasites grown from clinical samples by short-term in vitro culture. A newly described nested PCR assay was capable of amplifying genomic DNA from as few as five parasites in the presence of host tissues. Typing was based on DNA polymorphisms at the SAG2 loc...

Toxoplasma gondii is considered to be one of the most successful intracellular pathogens, because it can reproduce in varied nutritional milieus, encountered in diverse host cell types of essentially any warm-blooded organism. Our earlier work demonstrated that the acute (tachyzoite) stage of T. gondii depends on cooperativity of glucose and glutamine catabolism to meet biosynthetic demands. Ei...

Classical treatment for congenital toxoplasmosis is based on combination of sulfadiazine and pyrimethamine plus folinic acid. Due to teratogenic effects and bone marrow suppression caused by pyrimethamine, the establishment of new therapeutic strategies is indispensable to minimize the side effects and improve the control of infection. Previous studies demonstrated that enrofloxacin and toltraz...

AIMS To assess the diagnostic usefulness of Toxoplasma gondii tachyzoites produced by serial passage in HeLa cell culture. METHODS Tachyzoites derived from serial passage in cell culture were used in the dye test. Human sera were also examined to determine their suitability for use as accessory factor. Using the optimum conditions, the dye test using cell culture derived tachyzoites was compa...

Aims—To assess the diagnostic usefulness of Toxoplasma gondii tachyzoites produced by serial passage in HeLa cell culture. Methods—Tachyzoites derived from serial passage in cell culture were used in the dye test. Human sera were also examined to determine their suitability for use as accessory factor. Using the optimum conditions, the dye test using cell culture derived tachyzoites was compare...