Related Experiment Video
Updated: Jun 29, 2026
13:35
Plunge Freezing: A Tool for the Ultrastructural and Immunolocalization Studies of Suspension Cells in Transmission Electron Microscopy
Published on: May 5, 2017
Ultrastructural study of hepatic granulomas induced by Cryptococcus neoformans by quick-freezing and deep-etching
1Department of Pathology, Shinshu University School of Medicine, Matsumoto, Japan.
Virchows Archiv. B, Cell Pathology Including Molecular Pathology
|January 1, 1993
Summary
This study reveals the role of actin filaments in macrophage function during Cryptococcus neoformans infections. Actin networks are crucial for macrophage pseudopodia and phagocytosis in hepatic granulomas.
Area of Science:
- Immunology
- Cell Biology
- Mycology
Background:
- Hepatic granulomas are key to controlling Cryptococcus (C.) neoformans infections.
- Understanding macrophage ultrastructure is vital for deciphering granuloma formation and host defense.
Purpose of the Study:
- To investigate the ultrastructural basis of macrophage function within hepatic granulomas induced by C. neoformans.
- To identify cytoskeletal components involved in macrophage-mediated phagocytosis of yeast cells.
Main Methods:
- Utilized quick-freezing and deep-etching (QF-DE) for high-resolution ultrastructural analysis.
- Inoculated rats intravenously with viable C. neoformans yeast cells.
- Prepared liver tissues for QF-DE replica imaging.
Main Results:
- Identified intermediate filaments in the perinuclear region and extensive actin filament networks in macrophage cytoplasm.
- Observed two types of macrophage pseudopodia: cobblestone-like and thin, long interdigitating forms.
- Found dense actin filament networks within pseudopodia, particularly those interacting with the C. neoformans capsule.
Conclusions:
- Actin filaments play a significant role in the force-generating mechanisms of phagocytosis.
- Macrophage cytoskeletal dynamics, especially actin, are critical for granuloma formation and pathogen clearance.
