Related Experiment Video
Updated: Jul 18, 2026
08:52
Live-cell Video Microscopy of Fungal Pathogen Phagocytosis
Published on: January 9, 2013
Autophagy in the pathogen Candida albicans.
Glen E Palmer1, Michelle N Kelly, Joy E Sturtevant
1Department of MIP, Louisiana State University Health Sciences Center School of Dentistry, 1100 Florida Avenue, Box F8-130, New Orleans, LA 70119, USA. gpalme@lsuhsc.edu
Microbiology (Reading, England)
|December 23, 2006
Summary
Autophagy, a cellular degradation process, is crucial for yeast adaptation. However, in Candida albicans, deleting the ATG9 gene, essential for autophagy, did not impact its differentiation or host cell interactions.
Area of Science:
- Cell Biology
- Microbiology
- Molecular Biology
Background:
- Autophagy is a fundamental eukaryotic cellular process for degrading macromolecules and organelles via the lysosome.
- This process is vital for cellular adaptation, differentiation, and development, as seen in Saccharomyces cerevisiae's sporulation and starvation survival.
- Candida albicans, an opportunistic pathogen, requires adaptation and differentiation for host colonization and infection, with the vacuole playing a key role in its stress response.
Purpose of the Study:
- To investigate the role of vacuole-mediated degradation through autophagy in Candida albicans.
- To determine the importance of the ATG9 gene, essential for autophagy, in C. albicans.
- To assess the impact of autophagy deficiency on C. albicans differentiation and host cell interactions.
Main Methods:
- Identification and deletion of the ATG9 gene in Candida albicans to create an autophagy-deficient mutant (atg9Δ).
- Assessment of the atg9Δ mutant's sensitivity to nitrogen starvation, growth rate, vacuole morphology, and resistance to other stresses.
- Evaluation of the atg9Δ mutant's differentiation capabilities (yeast-hypha, chlamydospore) and its survival and killing of a mouse macrophage-like cell line.
Main Results:
- The atg9Δ mutant was blocked in autophagy and cytoplasm-to-vacuole (cvt) trafficking, exhibiting sensitivity to nitrogen starvation.
- No defects were observed in the mutant's growth rate, vacuole morphology, or resistance to other tested stresses.
- The atg9Δ mutant showed no impairment in yeast-hypha or chlamydospore differentiation and was as efficient as control strains in surviving within and killing host macrophage cells.
Conclusions:
- Autophagy, mediated by ATG9, is specifically required for nitrogen starvation adaptation in C. albicans.
- Contrary to expectations based on other eukaryotes, autophagy does not appear to play a significant role in C. albicans differentiation.
- The study suggests that autophagy is largely dispensable for Candida albicans during its interaction with host cells, including survival and cytotoxicity.
More Related Videos
08:48Bio-energetics Investigation of Candida albicans Using Real-time Extracellular Flux Analysis
Published on: March 19, 2019
09:24Use of In Vivo Imaging to Screen for Morphogenesis Phenotypes in Candida albicans Mutant Strains During Active Infection in a Mammalian Host
Published on: October 12, 2022
Related Concept Videos
01:36Delivery Pathways to the Lysosome
Eukaryotic cells use different mechanisms to eliminate toxic waste obsolete and worn-out substances. Lysosomes play a pivotal role in this, and hence, these substances are carried to the lysosome from other parts of the cell and extracellular space through different pathways. The most elaborately studied pathways to the lysosome are the endocytic pathways.
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
01:27Autophagy
Autophagy is a self-digesting process by which a cell protects itself from threats both within and outside the cell, ranging from abnormal proteins to invading bacteria. In this process, obsolete components of the cell and invading microbes are degraded by hydrolytic enzymes active in an acidic environment of the lysosomal lumen.
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
01:20Candidiasis
Candidiasis is a fungal infection caused by opportunistic species of Candida. It can affect various anatomical sites, including the skin, oral cavity, nails, and genitourinary tract. Among its forms, vaginal candidiasis is the most common type of mucosal infection. It typically results from the overgrowth of Candida albicans in the vaginal mucosa. Under normal conditions, C. albicans exists as a commensal organism within the vaginal microbiota, regulated by the dominance of lactobacilli, which...
01:18Autophagic Cell Death
Christian de Duve discovered “autophagy,” a process in which cellular components are engulfed by membrane-bound organelles called autophagosomes. The autophagosomes then fuse with lysosomes to digest the enclosed contents. Autophagy is generally activated in cells to prevent cell death. However, cell death is triggered when the damage is beyond repair.
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
01:17Phagocytosis of Apoptotic Cells
Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or immature dendritic cells. Non-professional phagocytes such as epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
01:22Cellular Injury V: Apoptosis and Autophagy
Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...