Spontaneous stage differentiation of mouse-virulent Toxoplasma gondii RH parasites in skeletal muscle cells: an ultrastructural evaluation

Memórias do Instituto Oswaldo Cruz

Marialice Da Fonseca Ferreira-da-silva²  Renata Mendonça Rodrigues²  Elisabete Ferreira De Andrade²  Laís De Carvalho¹  Uwe Gross¹  Carsten G K Lüder¹  Helene Santos Barbosa² 

[1] ,Instituto Oswaldo Cruz-Fiocruz Laboratório de Biologia Estrutural Rio de Janeiro RJ ,Brasil

关键词: Toxoplasma gondii;    stage conversion;    T. gondii-host cell interaction;    skeletal muscle cell;    tachyzoite;    bradyzoite;   

DOI  :  10.1590/S0074-02762009000200012

来源: SciELO

【 摘 要 】

Although the predilection for Toxoplasma gondii to form cysts in the nervous system and skeletal and heart muscles has been described for more than fifty years, skeletal muscle cells (SkMCs) have not been explored as a host cell type to study the Toxoplasma-host cell interaction and investigate the intracellular development of the parasite. Morphological aspects of the initial events in the Toxoplasma-SkMC interaction were analysed and suggest that there are different processes of protozoan adhesion and invasion and of the subsequent fate of the parasite inside the parasitophorous vacuole (PV). Using scanning electron microscopy,Toxoplasma tachyzoites from the mouse-virulent RH strain were found to be attached to SkMCs by the anterior or posterior region of the body, with or without expansion of the SkMC membrane. This suggests that different types of parasite internalization occurred. Asynchronous multiplication and differentiation of T. gondii were observed. Importantly, intracellular parasites were seen to display high amounts of amylopectin granules in their cytoplasm, indicating that tachyzoites of the RH strain were able to differentiate spontaneously into bradyzoites in SkMCs. This stage conversion occurred in approximately 3% of the PVs. This is particularly intriguing as tachyzoites of virulent Toxoplasma strains are not thought to be prone to cyst formation. We discuss whether biological differences in host cells are crucial to Toxoplasma stage conversion and suggest that important questions concerning the host cell type and its relevance in Toxoplasma differentiation are still unanswered.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License