Visualization of Caspase Activation in Human Monocyte-Derived Macrophages
Published: August 31, 2023
Abstract
Source: Bolívar, B. E., et. al., Visualization of Inflammatory Caspases Induced Proximity in Human Monocyte-Derived Macrophages. J. Vis. Exp. (2022).
This video demonstrates the activation of caspase proteins in human macrophages using bimolecular fluorescence complementation reporter proteins. The pro-domains of caspase-1 are fused with non-fluorescent fragments of Venus proteins, which are recruited to inflammasome complexes. The proximity of inflammasomes induces the refolding and fluorescence of Venus fragments, confirming caspase activation in the macrophages.
Protocol
All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human welfare and have been reviewed by the local institutional review board. 1. Isolation of human monocytes and differentiation into macrophages Obtain anticoagulated blood from de-identified healthy individuals at a regional blood bank and isolate peripheral blood mononuclear cells (PBMCs) as indicated below. <st…
Representative Results
Figure 1: Schematic overview of the experimental workflow. Figure 2: Differentiation of CD14-monocytes and transfection of human MDM. (A) Representative bright-field images of CD14+ monocytes from peripheral…
Materials
| 48-well tissue culture2:34 plates | Genesee Scientific | 25-108 | |
| 10 cm Tissue Culture Dishes | VWR | 25382-166 | |
| 2 Mercaptoethanol 1000x | Thermo Fisher Scientific | 21985023 | |
| 8-well chambered coverglass with 1.5 HP coverglass | Cellvis | c8-1.5H-N | |
| AutoMACS columns | Miltenyi (Biotec) | 130-021-101 | For automated separation using AutoMACS Pro Separator only |
| AutoMACS Pro Separator | Miltenyi (Biotec) | 130-092-545 | For automated separation using AutoMACS Pro Separator only |
| AutoMACS Pro Washing Solution | Miltenyi (Biotec) | 130-092-987 | For automated separation using AutoMACS Pro Separator only |
| AutoMACS Rinsing Solution | Miltenyi (Biotec) | 130-091-222 | For automated separation using AutoMACS Pro Separator only |
| AutoMacs running buffer | Miltenyi (Biotec) | 130-091-221 | For manual or automated separation using QuadroMACS or AutoMACS pro Separator |
| Axio Observer Z1 motorized inverted microscope equipped with a CSU-X1A 5000 spinning disk unit | Zeiss | Any confocal microscope equipped with a laser module fitted with laser lines of 568 nm (RFP) and 488 or 512 nm (GFP or YFP) wavelengths can be used | |
| AxioObserver A1, Research-Grade Inverted Microscope | Zeiss | Any epifluorescence microscope with fluorescence filters capable of exciting 568 nm (RFP) and 488 or 512 nm (GFP or YFP) wavelengths can be used | |
| CD14+ MICROBEADS | Miltenyi (Biotec) | 130-050-201 | For manual or automated separation using QuadroMACS or AutoMACS pro Separator |
| DPBS without calcium chloride and magnesium chloride | Sigma | D8537-6x500ML | |
| DsRed mito plasmid | Clontech | 632421 | Similar plasmids that can be used as fluorescent reporters can be found on Addgene |
| Fetal Bovine Serum | Thermo Fisher Scientific | 10437028 | |
| Ficoll-Paque PLUS 6 x 100 mL | Sigma | GE17-1440-02 | |
| GlutaMAX Supplement (100x) | Thermo Fisher Scientific | 35050079 | |
| GM-CSF | Thermo Fisher Scientific | PHC2011 | |
| Hemin BioXtra, from Porcine, INSERT CHARACTR96.0% (HPLC) | Sigma | 51280-1G | |
| HEPES | Thermo Fisher Scientific | 15630106 | |
| Inflammatory caspase BiFC plasmids | Available by request from LBH lab | ||
| LPS-EB Ultrapure | Invivogen | TLRL-3PELPS | |
| LS Columns | Miltenyi (Biotec) | 130-042-401 | For manual separation using QuadroMACS Separator only |
| MACS 15 mL Tube Rack | Miltenyi (Biotec) | 130-091-052 | For manual separation using QuadroMACS Separator only |
| MACS MultiStand | Miltenyi (Biotec) | 130-042-303 | For manual separation using QuadroMACS Separator only |
| mCherry plasmid | Yungpeng Wang Lab | Similar plasmids that can be used as fluorescent reporters can be found on Addgene | |
| Neon Transfection System | Thermo Fisher Scientific | MPK5000 | Includes Neon electroporation device, pipette and pipette station |
| Neon Transfection System 10 µL Kit | Thermo Fisher Scientific | MPK1096 | Includes resuspension buffer R, resuspension buffer T, electrolytic buffer E, 96 x 10 µL Neon tips and Neon electroporation tubes |
| Nigericin sodium salt, ready made solution | Sigma | SML1779-1ML | |
| Penicillin-Streptomycin (10,000 U/mL) | Thermo Fisher Scientific | 15140122 | |
| Poly-D-Lysine Hydrobromide | Sigma | P7280-5mg | |
| QuadroMACS Separator | Miltenyi (Biotec) | 130-090-976 | For manual separation using QuadroMACS Separator only |
| qVD-OPh | Fisher (ApexBio) | 50-101-3172 | |
| RPMI 1640 Medium | Thermo Fisher Scientific | 11875119 | |
| Trypsin-EDTA (0.25%), phenol red | Thermo Fisher Scientific | 25200072 | |
| UltraPure 0.5 M EDTA, pH 8.0 | Thermo Fisher Scientific | 15575020 |
Cite This Article
Visualization of Caspase Activation in Human Monocyte-Derived Macrophages. J. Vis. Exp. (Pending Publication), e21616, doi: (2023).