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Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages
Published on: October 25, 2017
Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages
Saray Gutiérrez1, Martina Wolke2, Georg Plum2
1Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne; Cologne Cluster of Excellence in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne.
Abstract:
Salmonella typhimurium is a facultative intracellular bacterium that causes gastroenteritis in humans. After invasion of the lamina propria, S. typhimurium bacteria are quickly detected and phagocytized by macrophages, and contained in vesicles known as phagosomes in order to be degraded. Isolation of S. typhimurium-containing phagosomes have been widely used to study how S. typhimurium infection alters the process of phagosome maturation to prevent bacterial degradation. Classically, the isolation of bacteria-containing phagosomes has been performed by sucrose gradient centrifugation. However, this process is time-consuming, and requires specialized equipment and a certain degree of dexterity. Described here is a simple and quick method for the isolation of S. typhimurium-containing phagosomes from macrophages by coating the bacteria with biotin-streptavidin-conjugated magnetic beads. Phagosomes obtained by this method can be suspended in any buffer of choice, allowing the utilization of isolated phagosomes for a broad range of assays, such as protein, metabolite, and lipid analysis. In summary, this method for the isolation of S. typhimurium-containing phagosomes is specific, efficient, rapid, requires minimum equipment, and is more versatile than the classical method of isolation by sucrose gradient-ultracentrifugation.
Insights
A new method simplifies isolating Salmonella typhimurium-containing phagosomes from macrophages using magnetic beads. This rapid technique enhances studies on bacterial infection and phagosome maturation.
Area of Science:
- Microbiology
- Cell Biology
- Immunology
Background:
- Salmonella typhimurium is a human pathogen causing gastroenteritis.
- Macrophages engulf S. typhimurium within phagosomes, normally leading to bacterial degradation.
- Studying how S. typhimurium manipulates phagosome maturation is crucial for understanding infection.
Purpose of the Study:
- To develop a simpler, faster method for isolating S. typhimurium-containing phagosomes.
- To provide a more versatile isolation technique compared to traditional sucrose gradient centrifugation.
Main Methods:
- Coating S. typhimurium with biotin-streptavidin-conjugated magnetic beads.
- Isolating S. typhimurium-containing phagosomes from macrophages using magnetic separation.
- Suspending isolated phagosomes in various buffers for downstream analysis.
Main Results:
- The magnetic bead method is specific, efficient, and rapid.
- It requires minimal specialized equipment and dexterity.
- Isolated phagosomes are suitable for diverse analyses, including protein, metabolite, and lipid studies.
Conclusions:
- The biotin-streptavidin magnetic bead method offers a significant improvement for isolating S. typhimurium-containing phagosomes.
- This technique facilitates broader research applications in microbiology and host-pathogen interactions.
- It provides a valuable alternative to the labor-intensive sucrose gradient centrifugation method.
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