Structural changes of cell lines after the real and simulated inoculations with Cryptosporidium muris oocysts.
|Fakulta / Pracoviště MU|
|Popis||In the present study, two types of cell lines, HCT8 and HT29, were used for an in vitro cultivation of the gastric parasite Cryptosporidium muris (Cryptosporidiidae, Apicomplexa). Evaluations of structural changes of both cell lines were carried out after 24, 48 and 72 DPI using combined approaches of light, electron and confocal laser scanning microscopy. So far, we succeed to detect sporozoites released from oocysts, free sporozoites gliding on the cell line surface that were equipped with a typically prolonged apical end and seemed to search for appropriate infection site, and few structures closely resembling full or already emptied cryptosporidian parasitophorous sacs. Evidently, newly formed round cells or gaps in a discontinuous layer characteristic for young cell cultures were frequently preferred and attacked by invading sporozoites. Interestingly, after 24 DPI, both cell lines started to embrace unexcysted oocysts of C. muris. These oocysts were found to be completely or partially enveloped by projections of individual host cells. The experimental inoculation with polystyrene microspheres was designed in order to verify whether this behaviour of cell lines is provoked by oocysts of C. muris or it represents their innate reaction to foreign objects in general. The microspheres were found only occasionally to be covered by a tiny filamentous projections arising from host cells or remnants in old cell cultures. Direct comparison and evaluation of both cell lines inoculated either with C. muris oocysts or with polystyrene microspheres confirmedthat the enclosing of oocysts by HT29 and HCT8 cells was induced by the parasite. Based on present data, we consider this to be a natural adherence of biological garbage to the surface of polystyrene microspheres. Acknowledgement: Financial support was provided by a postdoctoral grant GPP506/10/P372.|