کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5806425 | 1555779 | 2007 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Calcium ionophore-induced egress of Toxoplasma gondii shortly after host cell invasion Calcium ionophore-induced egress of Toxoplasma gondii shortly after host cell invasion](/preview/png/5806425.png)
Calcium plays crucial roles in important events of Toxoplasma gondii life cycle, including motility, invasion and egress from the host cell. Calcium ionophore has been used to artificially trigger release of the parasites from infected cells. In this report we describe that calcium ionophore A21387 induced T. gondii egress from LLC-MK2 cells at times as early as 2Â h after entry. Addition of kinase inhibitors as staurosporine, wortmanine and genistein to the incubation medium significantly reduced ionophore-induced egress. The same occurred when the actin inhibitor cytochalasin D was used. Parasites egressed 2Â h post-infection from ionophore-treated cultures were unable of establishing infection in a new cell. S-VHS recording of egressing parasites showed that they assume an hourglass shape as they cross the plasma membrane, similar to the moving junction constriction observed during active invasion, and extrudes the conoid, similarly to what is also observed during invasion. Transmission and high resolution scanning electron microscopy revealed that the egressing tachyzoites are free from host cell derived membranes. These include plasma membrane and parasitophorous vacuole membranes as well as associated endoplasmic reticulum membranes. Taken together, these results indicate that although invasion and egress may share similar signaling pathways, as indicated by the effect of kinase and actin inhibitors, the tachyzoites move freely in the cytosol, a phenomenon very distinctive from invasion and that deserves attention.
Journal: Veterinary Parasitology - Volume 147, Issues 3â4, 20 July 2007, Pages 210-220