Flow Imaging of the Inflammasome: Evaluating ASC Speck Characteristics and Caspase-1 Activity

Methods Mol Biol. 2023:2635:185-202. doi: 10.1007/978-1-0716-3020-4_11.

Abstract

Examining inflammasome-associated speck structures is one of the most preferred and easiest ways to evaluate inflammasome activation. Microscopy-based evaluation of specks is preferable, but this approach is time-consuming and limited to small sample sizes. Speck-containing cells can also be quantitated by a flow cytometric method, time of flight inflammasome evaluation (TOFIE). However, TOFIE cannot perform single-cell analysis such as simultaneously visualizing ASC specks and caspase-1 activity, their location, and physical characteristics. Here we describe the application of an imaging flow cytometry-based approach that overcomes these limitations. Inflammasome and Caspase-1 Activity Characterization and Evaluation (ICCE) is a high-throughput, single-cell, rapid image analysis utilizing the Amnis ImageStream X instrument with over 99.5% accuracy. ICCE quantitatively and qualitatively characterizes the frequency, area, and cellular distribution of ASC specks and caspase-1 activity in mouse and human cells.

Keywords: Caspase-1; Imaging Flow Cytometry; Inflammasome.

MeSH terms

  • Animals
  • CARD Signaling Adaptor Proteins* / metabolism
  • Caspase 1 / metabolism
  • Caspases
  • Humans
  • Inflammasomes* / metabolism
  • Macrophages / metabolism
  • Mice
  • Microscopy
  • NLR Family, Pyrin Domain-Containing 3 Protein

Substances

  • Inflammasomes
  • CARD Signaling Adaptor Proteins
  • Caspases
  • Caspase 1
  • NLR Family, Pyrin Domain-Containing 3 Protein