Harnessing sensing systems towards urban sustainability transformation

Peer reviewe

Harnessing sensing systems towards urban sustainability transformation

Recent years have seen a massive development of geospatial sensing systems informing the use of space. However, rarely do these sensing systems inform transformation towards urban sustainability. Drawing on four global urban case examples, we conceptualize how passive and active sensing systems should be harnessed to secure an inclusive, sustainable and resilient urban transformation. We derive principles for stakeholders highlighting the need for an iterative dialogue along a sensing loop, new modes of governance enabling direct feeding of sensed information, an account for data biases in the sensing processes and a commitment to high ethical standards, including open access data sharing.</p

Protection of Hepatocytes from Cytotoxic T Cell Mediated Killing by Interferon-Alpha

&lt;p&gt;Background: Cellular immunity plays a key role in determining the outcome of hepatitis C virus (HCV) infection, although the majority of infections become persistent. The mechanisms behind persistence are still not clear; however, the primary site of infection, the liver, may be critical. We investigated the ability of CD8+ T-cells (CTL) to recognise and kill hepatocytes under cytokine stimulation.&lt;/p&gt; &lt;p&gt;Methods/Principle Findings: Resting hepatocytes cell lines expressed low levels of MHC Class I, but remained susceptible to CTL cytotoxicity. IFN-α treatment, in vitro, markedly increased hepatocyte MHC Class I expression, however, reduced sensitivity to CTL cytotoxicity. IFN-α stimulated hepatocyte lines were still able to present antigen and induce IFN-γ expression in interacting CTL. Resistance to killing was not due to the inhibition of the FASL/FAS- pathway, as stimulated hepatocytes were still susceptible to FAS-mediated apoptosis. In vitro stimulation with IFN-α, or the introduction of a subgenomic HCV replicon into the HepG2 line, upregulated the expression of the granzyme-B inhibitor–proteinase inhibitor 9 (PI-9). PI-9 expression was also observed in liver tissue biopsies from patients with chronic HCV infection.&lt;/p&gt; &lt;p&gt;Conclusion/Significance: IFN-α induces resistance in hepatocytes to perforin/granzyme mediate CTL killing pathways. One possible mechanism could be through the expression of the PI-9. Hindrance of CTL cytotoxicity could contribute to the chronicity of hepatic viral infections.&lt;/p&gt

Toll-Like Receptor 8 Agonist and Bacteria Trigger Potent Activation of Innate Immune Cells in Human Liver

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The study was supported by a Grant core funding from the Agency for Science Technology and Research (A*STAR, Singapore) and a Singapore Translational Research Investigator Award (NRMC/StaR/013/2012) to AB as well as NIHR Biomedical Centre, Oxford, WT 091663MA, NIAID1U19AI082630-01, Oxford Martin School funding and an NIHR Senior Investigator award to PK

Analysis of alternative triggers for PI-9 expression.

<p>A) The up-regulation of PI-9 was also found to be triggered by other inflammatory cytokines. HepG2 cells were treated for 16 hours with either IFN-γ at 100 IU/ml, or IL-1β at 50 ng/ml. GAPDH expression was used as a positive control. B) Stimulation of the HepG2 cell line with either IFN-γ (open squares) or IL-1β (open triangles) also inhibited CTL killing compared to the un-stimulated HepG2 cells (closed circle). C) HepG2 cells were left un-infected (Nil), or infected with either a baculovirus expressing a sub-genomic replicon (NS-replicon), or with a control baculovirus expressing LacZ (+Control). PI-9 expression was analysed by RT-PCR. PI-9 was strongly up-regulated only in the cells expressing the sub-genomic replicon. GAPDH expression was used as a positive control.</p

IFN- treatment did not protect a B-cell line.

<p>Treatment of a BCL with 1000 IU/ml IFN-α (open inverted triangles) prior to the cytotoxicity assay, did not reduce CTLs ability to kill the treated BCL compared to the untreated BCL (closed circles).</p

IFN-α reduces hepatocyte sensitivity to CTL cytotoxicity.

<p>Hepatocytes have been described as expressing low to no MHC Class I. As expected, IFN-α treatment increased the levels of MHC Class I on HepG2 (A) and HHL (B); filled curve represents an isotype control, the solid line represents the MCH Class I expression. C) HepG2 cells were stimulated for 16 hours with a serial dilution of IFN-α at 0 IU/ml (closed circles), 10 IU/ml (open diamonds), 100 IU/ml (open squares), and 1000 IU/ml (open inverted triangles), prior to cytotoxicity assay with the CTL line 2. Treatment with IFN-α reduced the HepG2 cells sensitivity to CTL cytotoxicity in a dose dependent manner. D) This phenomenon was also found with the novel human hepatocyte cell lines (HHL). HHL-17 cells were either left untreated (closed circles) or stimulated for 16 hours with 1000 IU/ml (open inverted triangles) prior to co-incubation with the CTL line 1.</p