TOPOGRAPHY AND CELLULAR INTERACTION: APPLICATION OF ATOMIC FORCE MICROSCOPY IN STUDIES WITH TOXOPLASMA GONDII
DOI:
https://doi.org/10.63330/aurumpub.021-006Palabras clave:
Toxoplasma gondii, Atomic force microscopy, Host–parasite interaction, Cell invasion, Nanomechanics, Cytoskeletal remodelingResumen
Toxoplasma gondii is an obligate intracellular protozoan capable of infecting a wide range of warm-blooded animals and remains a global health concern. Understanding the mechanisms underlying parasite–host cell interaction is essential for elucidating the initial steps of infection. In this study, we applied atomic force microscopy (AFM) combined with fluorescence microscopy to characterize, at nanometric resolution, the early stages of interaction between T. gondii tachyzoites (RH strain) and mammalian host cells (LLC-MK2 and HFF). A fixation protocol optimized with 4% formaldehyde and 1% glutaraldehyde ensured morphological preservation while maintaining suitable mechanical properties for topographical analysis. Quantitative evaluation of 100 cells per experiment revealed that, after 15 minutes of incubation, the majority of tachyzoites remained adhered to host cell surfaces, with fewer in contact or fully internalized. AFM imaging revealed host cell participation during invasion, showing localized membrane invaginations, conoid projections, and numerous actin-rich extensions resembling filopodia and tunneling nanotubes directed toward the parasite. Nanomechanical mapping demonstrated distinct height and elasticity patterns at the host–parasite interface, indicating active cytoskeletal remodeling and membrane engagement during internalization. These results highlight AFM as a powerful complementary approach to fluorescence microscopy, providing unprecedented insights into the topography, elasticity, and dynamic remodeling of host cell membranes during T. gondii invasion. Understanding these structural and mechanical interactions contributes to elucidating the early determinants of infection and may aid in identifying novel therapeutic targets.
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Esta obra está bajo una licencia internacional Creative Commons Atribución-NoComercial-SinDerivadas 4.0.
