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Visualizing Non-lytic Exocytosis of Cryptococcus neoformans from Macrophages Using Digital Light Microscopy
Published on: October 21, 2014
Visualizing non-lytic exocytosis of Cryptococcus neoformans from macrophages using digital light microscopy
Sabriya Stukes1, Arturo Casadevall2
1Department of Microbiology and Immunology, Albert Einstein College of Medicine; sabriya.stukes@phd.einstein.yu.edu.
Abstract:
Many aspects of the infection of macrophages by Cryptococcus neoformans have been extensively studied and well defined. However, one particular interaction that is not clearly understood is non-lytic exocytosis. In this process, yeast cells are released into the extracellular space by a poorly understood mechanism that leaves both the macrophage and Cn viable. Here, we describe how to follow a large number of individually infected macrophages for a 24 hr infection period by time-lapsed microscopy. Infected macrophages are housed in a heating chamber with a CO2 atmosphere attached to a microscope that provides the same conditions as a cell-culture incubator. Live digital microscopy can provide information about the dynamic interactions between a host and pathogen that is not available from static images. Being able to visualize each infected cell can provide clues as to how macrophages handle fungal infections, and vice versa. This technique is a powerful tool in studying the dynamics that are behind a complex phenomenon.
Insights
This study visualizes Cryptococcus neoformans (Cn) non-lytic exocytosis from macrophages using time-lapse microscopy. This technique reveals dynamic host-pathogen interactions, offering insights into fungal infection mechanisms.
Area of Science:
- Immunology
- Microbiology
- Cell Biology
Background:
- Macrophages are key immune cells involved in host defense against fungal pathogens like Cryptococcus neoformans.
- Non-lytic exocytosis, a mechanism for Cryptococcus neoformans (Cn) release from macrophages, remains poorly understood.
- This process allows both the pathogen and host cell to remain viable.
Purpose of the Study:
- To develop and apply a live microscopy technique for observing individual macrophage-Cryptococcus neoformans interactions over time.
- To investigate the dynamics of non-lytic exocytosis in real-time.
- To gain insights into the mechanisms by which macrophages handle fungal infections.
Main Methods:
- Utilized time-lapse microscopy to track individually infected macrophages for 24 hours.
- Maintained infected macrophages in a CO2-controlled heating chamber attached to a microscope.
- Simulated cell-culture incubator conditions to ensure cell viability during observation.
Main Results:
- Enabled visualization of dynamic interactions between macrophages and Cryptococcus neoformans.
- Provided a method to observe a large number of individually infected macrophages simultaneously.
- Captured real-time data on the non-lytic exocytosis process.
Conclusions:
- Live digital microscopy offers dynamic insights into host-pathogen interactions, surpassing static imaging.
- The developed technique is a powerful tool for studying complex cellular phenomena like fungal exocytosis.
- Visualizing these dynamics can elucidate macrophage responses to Cryptococcus neoformans infection.
