[Change of cytoskeleton and variance of Ca2+ in cultured cells during the invasion of Toxoplasma gondii].

OBJECTIVE:To explore the change of cytoskeleton and the variance of Ca2+ in cultured cells during the invasion of Toxoplasma gondii. METHODS:Tachyzoites suspensions were gathered by routine method and used to infect phagocytic cells (J774A.1) and non-phagocytic cells (HUVEC). The ability of T. gondii invading into the cells and the influence of cytoskeleton inhibitor, colchicine and cytochalasin D, were observed by microscopy. The rearrangement of cytoskeleton of cells was observed by fluoromicroscopy. By using laser scanning confocal microscope, the variance of Ca2+ in J774A.1 and HUVEC was detected. RESULTS:Ca2+ increased greatly in J774A.1 during the invasion of T. gondii (P<0.01) and PLC inhibitor, U73122, could block the increase of Ca2+ (P>0.05). The microfilaments of J774A.1 were agglomerated during the invasion of T. gondii. Cytoskeleton inhibitor, cytochalasin D (P<0.01) and colchicine (P< 0.05) significantly reduced the infection rate of J774A.1 cells. No considerable change of Ca2+ in HUVEC was found (P>0.05) during the invasion and cytoskeleton was not changed. Cytochalasin D and colchicine showed little effect on the infection rate of HUVEC. CONCLUSION:The concentration of Ca2+ increases greatly and cytoskeleton (mainly the microfilament) has been rearranged in phagocytic cell during the invasion of T. gondii, while both of them show no significant change in non-phagocytic cell.