Partner: Werner Müller


Recent publications
1.Kalliara E., Kardynska M., Bagnall J., Spiller David G., Müller W., Ruckerl D., Śmieja J., Biswas Subhra K., Paszek P., Post-transcriptional regulatory feedback encodes JAK-STAT signal memory of interferon stimulation, Frontiers in Immunology, ISSN: 1664-3224, DOI: 10.3389/fimmu.2022.947213, Vol.13, pp.947213-1-19, 2022
Abstract:

Immune cells fine tune their responses to infection and inflammatory cues. Here, using live-cell confocal microscopy and mathematical modelling, we investigate interferon-induced JAK-STAT signalling in innate immune macrophages. We demonstrate that transient exposure to IFN-γ stimulation induces a long-term desensitisation of STAT1 signalling and gene expression responses, revealing a dose- and time-dependent regulatory feedback that controls JAK-STAT responses upon re-exposure to stimulus. We show that IFN-α/β1 elicit different level of desensitisation from IFN-γ, where cells refractory to IFN-α/β1 are sensitive to IFN-γ, but not vice versa. We experimentally demonstrate that the underlying feedback mechanism involves regulation of STAT1 phosphorylation but is independent of new mRNA synthesis and cognate receptor expression. A new feedback model of the protein tyrosine phosphatase activity recapitulates experimental data and demonstrates JAK-STAT network’s ability to decode relative changes of dose, timing, and type of temporal interferon stimulation. These findings reveal that STAT desensitisation renders cells with signalling memory of type I and II interferon stimulation, which in the future may improve administration of interferon therapy.

Keywords:

JAK-STAT network, STAT1 kinetics, interferons, pathway desensitisation, mathematical modelling, signal memory, live-cell microscopy

Affiliations:
Kalliara E.-other affiliation
Kardynska M.-other affiliation
Bagnall J.-other affiliation
Spiller David G.-other affiliation
Müller W.-other affiliation
Ruckerl D.-other affiliation
Śmieja J.-Silesian University of Technology (PL)
Biswas Subhra K.-other affiliation
Paszek P.-IPPT PAN
2.Papoutsopoulou S., Burkitt Michael D., Bergey F., England H., Hough R., Schmidt L., Spiller David G., White Michael H. R.R., Paszek P., Jackson Dean A., Martins Dos Santos Vitor A. P., Sellge G., Pritchard D. M., Campbell Barry J., Müller W., Probert Chris S., Macrophage-Specific NF-κB Activation Dynamics Can Segregate Inflammatory Bowel Disease Patients, Frontiers in Immunology, ISSN: 1664-3224, DOI: 10.3389/fimmu.2019.02168, Vol.10, pp.2168-1-11, 2019
Abstract:

The heterogeneous nature of inflammatory bowel disease (IBD) presents challenges, particularly when choosing therapy. Activation of the NF-κB transcription factor is a highly regulated, dynamic event in IBD pathogenesis. Using a lentivirus approach, NF-κB-regulated luciferase was expressed in patient macrophages, isolated from frozen peripheral blood mononuclear cell samples. Following activation, samples could be segregated into three clusters based on the NF-κB-regulated luciferase response. The ulcerative colitis (UC) samples appeared only in the hypo-responsive Cluster 1, and in Cluster 2. Conversely, Crohn's disease (CD) patients appeared in all Clusters with their percentage being higher in the hyper-responsive Cluster 3. A positive correlation was seen between NF-κB-induced luciferase activity and the concentrations of cytokines released into medium from stimulated macrophages, but not with serum or biopsy cytokine levels. Confocal imaging of lentivirally-expressed p65 activation revealed that a higher proportion of macrophages from CD patients responded to endotoxin lipid A compared to controls. In contrast, cells from UC patients exhibited a shorter duration of NF-κB p65 subunit nuclear localization compared to healthy controls, and CD donors. Analysis of macrophage cytokine responses and patient metadata revealed a strong correlation between CD patients who smoked and hyper-activation of p65. These in vitro dynamic assays of NF-κB activation in blood-derived macrophages have the potential to segregate IBD patients into groups with different phenotypes and may therefore help determine response to therapy.

Keywords:

inflammatory bowel disease, NF-kB, macrophages, cytokines, Crohn’s disease, ulcerative colitis

Affiliations:
Papoutsopoulou S.-other affiliation
Burkitt Michael D.-other affiliation
Bergey F.-other affiliation
England H.-other affiliation
Hough R.-other affiliation
Schmidt L.-other affiliation
Spiller David G.-other affiliation
White Michael H. R.R.-University of Manchester (GB)
Paszek P.-other affiliation
Jackson Dean A.-other affiliation
Martins Dos Santos Vitor A. P.-other affiliation
Sellge G.-other affiliation
Pritchard D. M.-other affiliation
Campbell Barry J.-other affiliation
Müller W.-other affiliation
Probert Chris S.-other affiliation
3.Bagnall J., Boddington C., England H., Brignall R., Downton P., Alsoufi Z., Boyd J., Rowe W., Bennett A., Walker C., Adamson A., Patel Nisha M. X., O’Cualain R., Schmidt L., Spiller David G., Jackson Dean A., Müller W., Muldoon M., White Michael R. H.R., Paszek P., Quantitative analysis of competitive cytokine signaling predicts tissue thresholds for the propagation of macrophage activation, Science Signaling, ISSN: 1945-0877, DOI: 10.1126/scisignal.aaf3998, Vol.11, No.540, pp.1-15, 2018
Abstract:

Toll-like receptor (TLR) signaling regulates macrophage activation and effector cytokine propagation in the constrained environment of a tissue. In macrophage populations, TLR4 stimulates the dose-dependent transcription of nuclear factor κB (NF-κB) target genes. However, using single-RNA counting, we found that individual cells exhibited a wide range (three orders of magnitude) of expression of the gene encoding the proinflammatory cytokine tumor necrosis factor–α (TNF-α). The TLR4-induced TNFA transcriptional response correlated with the extent of NF-κB signaling in the cells and their size. We compared the rates of TNF-α production and uptake in macrophages and mouse embryonic fibroblasts and generated a mathematical model to explore the heterogeneity in the response of macrophages to TLR4 stimulation and the propagation of the TNF-α signal in the tissue. The model predicts that the local propagation of the TLR4-dependent TNF-α response and cellular NF-κB signaling are limited to small distances of a few cell diameters between neighboring tissue-resident macrophages. In our predictive model, TNF-α propagation was constrained by competitive uptake of TNF-α from the environment, rather than by heterogeneous production of the cytokine. We propose that the highly constrained architecture of tissues enables effective localized propagation of inflammatory cues while avoiding out-of-context responses at longer distances.

Affiliations:
Bagnall J.-other affiliation
Boddington C.-other affiliation
England H.-other affiliation
Brignall R.-other affiliation
Downton P.-other affiliation
Alsoufi Z.-other affiliation
Boyd J.-other affiliation
Rowe W.-other affiliation
Bennett A.-other affiliation
Walker C.-other affiliation
Adamson A.-other affiliation
Patel Nisha M. X.-other affiliation
O’Cualain R.-other affiliation
Schmidt L.-other affiliation
Spiller David G.-other affiliation
Jackson Dean A.-other affiliation
Müller W.-other affiliation
Muldoon M.-other affiliation
White Michael R. H.R.-University of Manchester (GB)
Paszek P.-other affiliation