Cytotoxin Caga
Cytotoxin Caga - Related Videos
03:30
Establishing an Infection Model Through Microinjection of Gastric Organoids with Pathogenic Bacteria
0 Views •
2025
This video demonstrates a method to establish a gastric organoid infection model by microinjecting gastric pathogen Helicobacter pylori into the lumen of the organoids. This model helps in studying infection-induced changes in gastric cells.
02:19
Modeling Aeromonas Pathogenesis in C. elegans Using a Survival Assay
0 Views •
2026
Source: Chen, Y., et al. Evaluating Virulence and Pathogenesis of Aeromonas Infection in a Caenorhabditis elegans Model. J. Vis. Exp. (2018)This video demonstrates a survival assay using C. elegans to model Aeromonas pathogenesis, where oral ingestion of the bacteria leads to intestinal infection and mortality, enabling quantitative assessment of bacterial virulence in a live host system.
01:15
Assessing the Role of Gut Microbiota in Modulating Hepatitis B Infection in Mice
0 Views •
2026
Take a control mouse with a normal gut microbiota and an experimental mouse with depleted gut microbiota. The depletion compromises the integrity of the gut barrier.This enables bacteria to translocate through the blood vessel into the liver tissue.Inject both mice with the hepatitis B virus or HBV plasmid to induce an HBV infection in the liver tissue.In the control mouse, the T cell detects an infected liver cell through the interaction of its receptors with viral antigens, and produces...
09:23
Parasite Induced Genetically Driven Autoimmune Chagas Heart Disease in the Chicken Model
0 Views •
Cited by 12 •
2012
The inoculation of Trypanosoma cruzi in fertile eggs prior to incubation renders the parasite kDNA minicircle integration in embryo cells genome. Crossbreeding reveals the vertical transfer of the mutations to progeny. The kDNA integrates into coding regions at several chromosomes and the chickens die with an inflammatory autoimmune heart disease.
FAQs
The type IV secretion system transfers CagA from attached Helicobacter pylori into gastric epithelial cells. Once inside, host-cell kinases phosphorylate the protein, a chemical modification that enables CagA to influence cellular signaling. This delivery-and-modification sequence is essential because it connects bacterial attachment with the intracellular changes associated with epithelial disruption.
Phosphorylation by host kinases enables CagA to alter signaling pathways within gastric epithelial cells. Through this activated state, the protein can influence cell polarity, cytoskeletal organization, and cell-cell junctions. These coordinated changes matter because they can disturb the normal structure and behavior of the epithelial layer rather than producing only a localized biochemical effect.
After entering host cells, CagA affects signaling systems that regulate polarity, the cytoskeleton, and cell-cell junctions. These components help epithelial cells maintain organized shape, positioning, and contacts with neighboring cells. Their disruption can produce abnormal epithelial behavior, providing a mechanistic link between bacterial virulence and tissue-level changes in the stomach.
A useful experimental sequence follows bacterial attachment, CagA injection through the type IV secretion system, phosphorylation by host kinases, and subsequent cellular responses. Researchers can then examine changes in signaling, polarity, cytoskeletal organization, and cell-cell junctions. Tracking these linked stages helps connect the bacterial interaction to its effects on epithelial function.
CagA-associated disruption of gastric epithelial cells can promote inflammation and abnormal epithelial behavior. In the broader disease context, these effects contribute to gastritis and peptic ulcer disease and are associated with an increased risk of gastric cancer. Studying the cellular changes therefore helps relate bacterial pathogenesis to both immediate tissue injury and longer-term disease outcomes.
CagA provides a model for understanding how a bacterial effector can redirect host-cell processes after entering an epithelial cell. Its effects on signaling, polarity, cytoskeletal organization, and junctions illustrate mechanisms of bacterial pathogenesis. This research can also help identify targets for prevention or treatment of diseases linked to Helicobacter pylori infection.