3D Spatial Interactomics Maps the Dynamics of NF-κB Multiprotein Signalosomes in Single Cells
Related research and updatesSynopsis
This work introduces an intelligent sequential proximity ligation assay (iseqPLA) read out by spinning disk confocal microscopy and 3D reconstruction to profile endogenous NF-κB protein-protein interactions inside single cells, treating clusters of co-localized puncta as a measure of supercomplex spatial organization, and tracks supercomplex dissociation, p65 nuclear translocation, and negative-feedback engagement across cytokine time courses in NIH-3T3 mouse fibroblasts, cystic fibrosis (CF) patient-derived macrophage co-cultures with IMR-90 human fibroblasts, and an independent set of healthy- and CF-donor monocyte-fibroblast co-cultures, reporting three findings: 3D volumetric quantification reduces the variance in nuclear-to-cytoplasmic ratio measurements relative to 2D projections, th
Interpretation
A 3D spatial interactomics workflow was established that uses iseqPLA to detect endogenous NF-κB protein-protein proximity events, representing each event by a rolling-circle amplification product and treating clusters of co-localized puncta as a measure of supercomplex spatial organization. The text states that how NF-κB signalosomes are organized in space and time within the 3D interior of a single cell had remained uncharacterized; this work couples proximity ligation readout with spinning disk confocal microscopy and 3D reconstruction to place interaction measurements in a 3D volume. The methodological description is explicit: iseqPLA, spinning disk confocal microscopy, and 3D reconstruction, applied across multiple cell systems (NIH-3T3, CF patient-derived macrophage co-cultures with IMR-90, and an independent set of healthy- and CF-donor monocyte-fibroblast co-cultures); the loaded text is summary-level and does not provide sample sizes or statistics.
3D volumetric quantification reduces the variance in nuclear-to-cytoplasmic ratio measurements relative to 2D projections. This is one of the three findings listed in the text, directly comparing 3D volumetric quantification with 2D projections for nuclear-to-cytoplasmic ratio measurement. The text phrases this as 'reduces the variance,' a quantitative methodological comparison; no variance values, sample sizes, or statistical test details are given in the text.
The choice of extracellular matrix coating shapes the fraction of NF-κB-responsive cells. The text presents matrix coating as a factor influencing the fraction of NF-κB-responsive cells, suggesting that microenvironmental conditions contribute to response heterogeneity. The text phrases this as 'shapes the fraction of NF-κB-responsive cells,' an association observed in the cell systems used; no specific fraction values or dose-response relationships are reported in the text.
In a CF model, CF airway-conditioned macrophages amplify paracrine NF-κB signaling in neighboring fibroblasts. The text lists this as one of the three findings, linking CF-derived macrophages to paracrine signal amplification in neighboring fibroblasts. This conclusion rests on CF patient-derived macrophage co-cultures with IMR-90 human fibroblasts and on an independent set of healthy- and CF-donor monocyte-fibroblast co-cultures profiled by 3D iseqPLA; the text does not report effect sizes or statistical details.
Perspective
This work is aimed at researchers who need to track protein complex assembly and dissociation in single-cell 3D space, and it applies to experimental settings that read out protein-protein proximity events by proximity ligation and characterize supercomplexes through co-localized puncta clusters; the results described come from NIH-3T3 mouse fibroblasts, CF patient-derived macrophage co-cultures with IMR-90 human fibroblasts, and an independent set of healthy- and CF-donor monocyte-fibroblast co-cultures, covering supercomplex dissociation, p65 nuclear translocation, and negative-feedback engagement across cytokine time courses. Its transferability lies in bringing 3D volumetric quantification, matrix coating conditions, and paracrine signal amplification into one analytical frame for continued use in inflammation-related cells and disease models.
The loaded text is summary-level and contains no figures, sample sizes, statistics, or effect sizes, so the magnitude of the 3D-versus-2D variance comparison, the specific values by which matrix coating shapes the responsive-cell fraction, and the quantitative extent of paracrine amplification by CF airway-conditioned macrophages cannot be judged from the text; how the scGPT model fine-tuned on curated transcriptomic datasets places the NF-κB gene panel within an inflammation-relevant feature space, including its specific features and validation, would require the original figures; and the reproducibility of these findings in other cell types, other species, or in vivo settings remains an open question.
