Application of Fluorescent Nanoparticles to Study Remodeling of the Endo-lysosomal System by Intracellular Bacteria
January 2nd, 2015
This article describes methods for the synthesis and fluorescent labeling of nanoparticles (NPs). The NPs were applied in pulse-chase experiments to label the endo-lysosomal system of eukaryotic cells. Manipulation of the endo-lysosomal system by activities of the intracellular pathogen Salmonella enterica were followed by live cell imaging and quantified.
Overview
This article describes methods for studying the remodeling of the endo-lysosomal system by intracellular bacteria using fluorescent nanoparticles as tracers. The approach involves live cell imaging to observe the effects of Salmonella enterica on host cells.
Key Study Components
Area of Science
- Cell Biology
- Microbiology
- Fluorescent Imaging
Background
- Understanding the endo-lysosomal system is crucial for cell biology.
- Intracellular pathogens like Salmonella can manipulate host cellular processes.
- Fluorescent nanoparticles provide a novel way to track cellular changes.
- Live cell imaging allows for real-time observation of cellular dynamics.
Purpose of Study
- To investigate how Salmonella enterica affects the endo-lysosomal system.
- To utilize fluorescent nanoparticles for tracking cellular changes.
- To quantify the distribution of nanoparticles within host cells.
Methods Used
- Seeding HeLa cells in an eight-well chamber slide.
- Infecting cells with Salmonella enterica.
- Performing pulse-chase labeling with gold BSA Rumine nanoparticles.
- Observing alterations using confocal microscopy and quantifying with MRS software.
Main Results
- Successful labeling of the endo-lysosomal system with nanoparticles.
- Observation of significant alterations in host cell dynamics post-infection.
- Quantitative analysis of nanoparticle distribution was achieved.
- Live cell imaging provided insights into the interaction between Salmonella and host cells.
Conclusions
- Fluorescent nanoparticles are effective for studying cellular processes.
- Salmonella enterica significantly remodels the endo-lysosomal system.
- This method can be applied to further research on intracellular pathogens.
Frequently Asked Questions
Executive Industry Relevance
Quantitative tracking of endo-lysosomal remodeling by intracellular pathogens is critical for de-risking host-pathogen interaction targets in early discovery. The use of fluorescent nanoparticles enables high-content, reproducible measurement of vesicular dynamics and manipulation by Salmonella, supporting predictive confidence in target validation. This approach strengthens portfolio decisions by providing robust, quantitative readouts of host cell pathway alterations relevant to infectious disease and immunology pipelines.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables direct visualization and quantification of host cell compartment remodeling by intracellular bacteria.
- Supports mechanistic de-risking of host-pathogen interaction targets through quantitative imaging outputs.
- Facilitates functional validation of candidate targets involved in vesicular trafficking and immune evasion.
Screening & Assay Development
- Provides a standardized, reproducible system for labeling and tracking endo-lysosomal compartments in live cells.
- Delivers quantitative, image-based readouts suitable for assay development and compound screening workflows.
- Enables scalability and platform reuse across different cell types and intracellular pathogens.
Translational & Preclinical Research
- Aligns with disease-relevant models of host-pathogen interaction for translational biomarker discovery.
- Supports continuity from discovery through preclinical validation by enabling quantitative assessment of cellular remodeling.
- Reduces biological ambiguity in preclinical models of infection and immune modulation.
Pipeline & Workflow Integration
This method integrates into the discovery-to-preclinical continuum by enabling hypothesis testing, quantitative imaging, and statistical analysis of host cell remodeling events.
- Discovery Biology: Supports hypothesis-driven interrogation of vesicular trafficking and host-pathogen interactions.
- Screening: Provides reproducible, quantitative outputs for assay standardization and compound evaluation.
- Analytics: Delivers object count and size distribution metrics for robust statistical comparison between conditions.
- Translational Research: Facilitates alignment with disease-relevant cellular phenotypes in infection models.
- Enterprise Reuse: Offers a reusable imaging and analysis platform adaptable to multiple pathogens and cell systems.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in target validation.
- Operational Value: Standardizes imaging and analysis workflows for reproducibility and scalability.
- Strategic Value: Improves go/no-go decisions and capital efficiency by providing robust quantitative data.
- Portfolio Impact: Enables risk-adjusted prioritization of host-pathogen interaction targets and pathways.
Implementation Considerations
- Requires expertise in confocal microscopy and quantitative image analysis.
- Needs access to validated fluorescent nanoparticle reagents and imaging infrastructure.
- Demands cross-team standardization of labeling, imaging, and analysis protocols.
- Adaptable to various cell lines and intracellular pathogens with protocol optimization.
- Dependent on robust statistical analysis software for quantitative output extraction.
Biopharma FAQs
Chapters in this video
0:05
Title
1:26
Synthesis of 10-nm Gold Nanoparticles (Gold NPs)
2:28
Coating of Gold NPs with BSA and Labeling with Rhodamine N-hydroxysuccinimidyl Ester (NHS)
4:30
Culture of HeLa Cells and Salmonella Bacteria
5:40
Infection of HeLa Cells by Salmonella and Gold-BSA-Rhodamine NPs Pulse Chase-labeling
7:04
Imaging and Image Analysis
9:18
Results: Salmonella Infection Rearranges the Endolysosomal System in HeLa Cells
10:58
Conclusion
