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Updated: Apr 5, 2026
Extraction of Tissue Antigens for Functional Assays
Published on: September 10, 2012
Artificial Loading of ASC Specks with Cytosolic Antigens
Ali Can Sahillioğlu1, Nesrin Özören2
1Apoptosis and Cancer Immunology Laboratory (AKiL), Department of Molecular Biology and Genetics, Bogazici University, Istanbul, Turkey.
Abstract:
Inflammasome complexes form upon interaction of Nod Like Receptor (NLR) proteins with pathogen associated molecular patterns (PAPMS) inside the cytosol. Stimulation of a subset of inflammasome receptors including NLRP3, NLRC4 and AIM2 triggers formation of the micrometer-sized spherical supramolecular complex called the ASC speck. The ASC speck is thought to be the platform of inflammasome activity, but the reason why a supramolecular complex is preferred against oligomeric platforms remains elusive. We observed that a set of cytosolic proteins, including the model antigen ovalbumin, tend to co-aggregate on the ASC speck. We suggest that co-aggregation of antigenic proteins on the ASC speck during intracellular infection might be instrumental in antigen presentation.
Insights
Inflammasome activation leads to ASC speck formation, a platform where cytosolic proteins, including antigens, co-aggregate. This aggregation may enhance antigen presentation during intracellular infections.
Area of Science:
- Immunology
- Cell Biology
- Molecular Biology
Background:
- Inflammasome complexes, initiated by Nod Like Receptor (NLR) proteins and pathogen-associated molecular patterns (PAMPs), are crucial for innate immunity.
- Activation of specific inflammasome receptors (NLRP3, NLRC4, AIM2) results in the formation of the ASC speck, a large supramolecular complex.
- The functional advantage of the ASC speck as a supramolecular platform over simpler oligomeric structures for inflammasome activity is not fully understood.
Purpose of the Study:
- To investigate the functional role of the ASC speck beyond inflammasome signaling.
- To explore the interactions of cytosolic proteins with the ASC speck.
- To propose a novel function for the ASC speck in antigen presentation.
Main Methods:
- Observation of protein co-aggregation on the ASC speck.
- Utilizing a model antigen (ovalbumin) to study co-aggregation dynamics.
Main Results:
- Cytosolic proteins, including the model antigen ovalbumin, were observed to co-aggregate on the ASC speck.
- The ASC speck appears to serve as a platform for the aggregation of various cytosolic proteins.
Conclusions:
- The ASC speck's supramolecular organization may facilitate the co-aggregation of antigenic proteins.
- This co-aggregation on the ASC speck could play a significant role in enhancing antigen presentation during intracellular infections.
