Responses of cell lines to the real and simulated inoculations with Cryptosporidium muris oocysts.
|Fakulta / Pracoviště MU|
|Popis||In present study two types of cell lines, HCT8 and HT29, were used for an in vitro cultivation of the gastric parasite Cryptosporidium muris. Our observations were carried out after 24, 48 and 72 DPI using combined approach of light, electron and confocal laser scanning microscopy. So far, we succeed to detect free sporozoites with typically prolonged apical ends that seemed to search for appropriate host cell/infection site, few structures closely resembling full or already emptied cryptosporidian parasitophorous sacs, and free merozoites especially in HT29 cell line. Evidently, invading sporozoites preferred newly formed round cells or gaps in a discontinuous layer characteristic for young cell cultures. Interestingly, however, unexcysted oocysts of C. muris were found to be completely or partially enveloped by projections of individual host cells after 24 DPI in both cell lines. 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. Direct comparison and evaluation of both cell lines inoculated either with C. muris oocysts or with polystyrene microspheres confirmed that the enclosing of oocysts by HT29 and HCT8 cells was induced by the parasite. The microspheres were found only occasionally to be covered by a tiny filamentous projections arising from host cells or remnants from old cell cultures. Based on present data, we consider this to be a natural adherence of biological garbage to the surface of polystyrene microspheres. Financial support was provided by a postdoctoral grant GPP506/10/P372 and partially by the project GAP505/11/1163, both from the Czech Science Foundation.|