Related Experiment Video
Updated: Jun 28, 2025
An Optogenetic Method to Control and Analyze Gene Expression Patterns in Cell-to-cell Interactions
Published on: March 22, 2018
Gene Delivery and Analysis of Optogenetic Induction of Lytic Cell Death
Teak-Jung Oh1,2, Bryan Gworek3,2, Amna Mehfooz1,2
1Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois.
Abstract:
Necroptosis is a form of inflammatory lytic cell death involving active cytokine production and plasma membrane rupture. Progression of necroptosis is tightly regulated in time and space, and its signaling outcomes can shape the local inflammatory environment of cells and tissues. Pharmacological induction of necroptosis is well established, but the diffusive nature of chemical death inducers makes it challenging to study cell-cell communication precisely during necroptosis. Receptor-interacting protein kinase 3, or RIPK3, is a crucial signaling component of necroptosis, acting as a crucial signaling node for both canonical and non-canonical necroptosis. RIPK3 oligomerization is crucial to the formation of the necrosome, which regulates plasma membrane rupture and cytokine production. Commonly used necroptosis inducers can activate multiple downstream signaling pathways, confounding the signaling outcomes of RIPK3-mediated necroptosis. Opsin-free optogenetic techniques may provide an alternative strategy to address this issue. Optogenetics uses light-sensitive protein-protein interaction to modulate cell signaling. Compared to chemical-based approaches, optogenetic strategies allow for spatiotemporal modulation of signal transduction in live cells and animals. We developed an optogenetic system that allows for ligand-free optical control of RIPK3 oligomerization and necroptosis. This article describes the sample preparation, experimental setup, and optimization required to achieve robust optogenetic induction of RIPK3-mediated necroptosis in colorectal HT-29 cells. We expect that this optogenetic system could provide valuable insights into the dynamic nature of lytic cell death. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Production of lentivirus encoding the optogenetic RIPK3 system Support Protocol: Quantification of the titer of lentivirus Basic Protocol 2: Culturing, chemical transfection, and lentivirus transduction of HT-29 cells Basic Protocol 3: Optimization of optogenetic stimulation conditions Basic Protocol 4: Time-stamped live-cell imaging of HT-29 lytic cell death Basic Protocol 5: Quantification of HT-29 lytic cell death.
Insights
Researchers developed an optogenetic system for precise control over necroptosis, a form of inflammatory cell death. This method enables studying cell communication during RIPK3-mediated necroptosis with spatiotemporal accuracy.
Area of Science:
- Cell Biology
- Molecular Biology
- Immunology
Background:
- Necroptosis is an inflammatory cell death pathway crucial for tissue homeostasis and immunity.
- Chemical inducers of necroptosis lack spatiotemporal precision, hindering studies of cell-cell communication.
- Receptor-interacting protein kinase 3 (RIPK3) is a central regulator of necroptosis, but its signaling is often confounded by broad pathway activation.
Purpose of the Study:
- To develop an optogenetic system for precise, ligand-free optical control of RIPK3 oligomerization and necroptosis.
- To overcome the limitations of chemical inducers in studying necroptosis signaling and cell communication.
- To enable spatiotemporal modulation of RIPK3-mediated necroptosis in live cells.
Main Methods:
- Development of an opsin-free optogenetic system for controlling RIPK3 oligomerization.
- Lentivirus-mediated gene delivery for expressing the optogenetic RIPK3 system in HT-29 cells.
- Optimization of light stimulation conditions and time-stamped live-cell imaging for monitoring necroptosis.
Main Results:
- Successful establishment of an optogenetic system for robust, light-induced RIPK3-mediated necroptosis in HT-29 cells.
- Demonstration of spatiotemporal control over necroptosis induction, allowing precise timing and localization.
- Validation of experimental protocols for lentivirus production, cell transduction, and necroptosis quantification.
Conclusions:
- Optogenetic control of RIPK3 provides a powerful tool to dissect the dynamics of necroptosis.
- This system offers a precise alternative to chemical inducers for studying cell death and communication.
- The developed methodology facilitates deeper insights into the inflammatory microenvironment shaped by lytic cell death.
