Related Experiment Video
Updated: Jul 2, 2025
Author Spotlight: THP-1 Macrophage Response to LPS/ATP — Unveiling the Pyroptosis, Apoptosis, and Necroptosis Spectrum
Published on: May 3, 2024
A comparative study of apoptosis, pyroptosis, necroptosis, and PANoptosis components in mouse and human cells
Sk Mohiuddin Choudhury1, Roman Sarkar1, Rajendra Karki1
1Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, United States of America.
Abstract:
Regulated cell death is a key component of the innate immune response, which provides the first line of defense against infection and homeostatic perturbations. However, cell death can also drive pathogenesis. The most well-defined cell death pathways can be categorized as nonlytic (apoptosis) and lytic (pyroptosis, necroptosis, and PANoptosis). While specific triggers are known to induce each of these cell death pathways, it is unclear whether all cell types express the cell death proteins required to activate these pathways. Here, we assessed the protein expression and compared the responses of immune and non-immune cells of human and mouse origin to canonical pyroptotic (LPS plus ATP), apoptotic (staurosporine), necroptotic (TNF-α plus z-VAD), and PANoptotic (influenza A virus infection) stimuli. When compared to fibroblasts, both mouse and human innate immune cells, macrophages, expressed higher levels of cell death proteins and activated cell death effectors more robustly, including caspase-1, gasdermins, caspase-8, and RIPKs, in response to specific stimuli. Our findings highlight the importance of considering the cell type when examining the mechanisms regulating inflammation and cell death. Improved understanding of the cell types that contain the machinery to execute different forms of cell death and their link to innate immune responses is critical to identify new strategies to target these pathways in specific cellular populations for the treatment of infectious diseases, inflammatory disorders, and cancer.
Insights
Innate immune cells like macrophages robustly activate cell death pathways, unlike fibroblasts. This highlights cell type importance in understanding regulated cell death and innate immunity for disease treatment.
Area of Science:
- Immunology
- Cell Biology
- Molecular Biology
Background:
- Regulated cell death is crucial for innate immunity and homeostasis but can also cause disease.
- Key pathways include nonlytic apoptosis and lytic pyroptosis, necroptosis, and PANoptosis.
- The cell-type specificity of cell death pathway execution machinery remains unclear.
Purpose of the Study:
- To investigate protein expression of cell death pathways across different human and mouse cell types.
- To compare the activation of cell death pathways in immune versus non-immune cells.
- To determine the role of cell type in innate immune responses and regulated cell death.
Main Methods:
- Assessed protein expression of cell death effectors in human and mouse immune (macrophages) and non-immune (fibroblasts) cells.
- Stimulated cells with canonical inducers for pyroptosis (LPS + ATP), apoptosis (staurosporine), necroptosis (TNF-α + z-VAD), and PANoptosis (influenza A virus).
- Quantified activation of key mediators like caspase-1, gasdermins, caspase-8, and RIPKs.
Main Results:
- Innate immune cells (macrophages) exhibited higher basal levels of cell death proteins compared to fibroblasts.
- Macrophages showed more robust activation of cell death effectors (caspase-1, gasdermins, caspase-8, RIPKs) upon specific stimuli.
- Cell type significantly influences the capacity to execute distinct regulated cell death pathways.
Conclusions:
- Cell type is a critical determinant in the execution of regulated cell death pathways.
- Innate immune cells possess a more comprehensive machinery for cell death execution than non-immune cells.
- Understanding cell-type specific death pathways is vital for developing targeted therapies for infectious diseases, inflammation, and cancer.
