Anionic sites on Toxoplasma gondii tissue cyst wall: Expression, uptake and characterization

Toxoplasma gondii Tissue Cyst: Cyst Wall Incorporation Activity and Matrix Cytoskeleton Proteins Paving the Way to Nutrient Acquisition

“…The cyst wall, due to its limiting, highly invaginated membrane, provides an enhancement of the cyst surface area, affording the traffic of material between the parasite intracyst and the host cell cytosol [25][26][27]. Our results show that the T. gondii cyst wall is able to incorporate fluids and macromolecules from the external environment via the formation of vesicles and tubules, corroborating findings [8], when there is endocytic activity of the cystic wall, a dynamic process that occurs in ex-vivo cysts. These properties might be an alternative method for parasite survival, remaining enclosed within cysts for a long period of time or, as proposed, for the entire life of the infected host [28,29].…”

“…Our previous ultrastructural analysis demonstrated that the cyst wall displays endocytic activity through the engulfing of negatively charged molecules in the cystic wall [8]. These molecules are incorporated by tubules and vesicles formed from the membrane that delimits the cyst wall and localized in the granular region and posteriorly in the cyst matrix.…”

“…Despite the clinical relevance of chronic toxoplasmosis, the biology of the cyst wall as yet has not been completely elucidated [4][5][6][7][8][9]. A 116-kDa glycoprotein termed CST1 [7] and two lectins, Dolichos biflorus and succinylated wheat-germ agglutinin, that bind specifically to the cyst wall, were identified, and it was suggested that chitin probably represents an important component of the cyst wall [10].…”

“…These molecules are incorporated by tubules and vesicles formed from the membrane that delimits the cyst wall and localized in the granular region and posteriorly in the cyst matrix. Within the cyst, the presence of vesicles containing the tracer in close contact to the bradyzoite membrane or in its neighborhood suggests that it could be one of the incorporated molecule pathways from the host cell cytoplasm to intracystic parasites [8]. The current knowledge of mechanisms involved in the process of nutrient uptake by this parasite still presents many gaps, restricted to few reports [12,13].…”

Spontaneous cystogenesis of Toxoplasma gondii in feline epithelial cells in vitro

“…After 4 and 12 weeks post-infection, the mice were sacrificed and the brain cysts were isolated as described previously (Freyre 1995, Popiel et al 1996guimarães et al 2007, 2008. Bradyzoites were obtained from the isolated tissue cysts (guimarães et al 2008).…”