Hyaluronic acid of low molecular weight triggers the invasive “hummingbird” phenotype on gastric cancer cells

The overproduction and deposition of hyaluronic acid (HA) of different sizes in the tumor microenvironment is associated with cancer metastasis. Here, the development of layerâ byâ layer (LbL) constructs containing HA of different molecular weights (i.e., 5.6, 618, and 1450 kDa) that mimic the HAâ rich cancer extracellular matrix is described to study the effect of the HA's size on the behavior of gastric cancer cells (AGS). The results demonstrate that LbL constructs with short HA, i.e., 5.6 kDa, activate the cytoskeleton rearrangement leading to the â hummingbirdâ morphology, promote high cellular motility, and activate signaling pathways with increased expression of pâ ERK1/2 and pâ AKT. In addition, it is demonstrated that this malignant transformation involves an active participation of the HA coreceptor RHAMM in AGS cells.The authors acknowledge the financial support from the European Commission’s H2020 Programme, under grant agreements H2020-WIDESPREAD-2014-668983-FORECAST and H2020-MSCA-RISE-2019-872648-MEPHOS. S.A. acknowledge the Portuguese Foundation for Science and Technology (FCT) for the PhD grant (SFRH/BD/112075/2015). The authors also thank Ramon Novoa-Caballal for performing the GPC experiments and data analysis

Interdependence between Interleukin-1 and Tumor Necrosis Factor Regulates TNF-Dependent Control of Mycobacterium tuberculosis Infection

SummaryThe interleukin-1 receptor I (IL-1RI) is critical for host resistance to Mycobacterium tuberculosis (Mtb), yet the mechanisms of IL-1RI-mediated pathogen control remain unclear. Here, we show that without IL-1RI, Mtb-infected newly recruited Ly6Ghi myeloid cells failed to upregulate tumor necrosis factor receptor I (TNF-RI) and to produce reactive oxygen species, resulting in compromised pathogen control. Furthermore, simultaneous ablation of IL-1RI and TNF-RI signaling on either stroma or hematopoietic cells led to early lethality, indicating non-redundant and synergistic roles of IL-1 and TNF in mediating macrophage-stroma cross-talk that was critical for optimal control of Mtb infection. Finally, we show that even in the presence of functional Mtb-specific adaptive immunity, the lack of IL-1α and not IL-1β led to an exuberant intracellular pathogen replication and progressive non-resolving inflammation. Our study reveals functional interdependence between IL-1 and TNF in enabling Mtb control mechanisms that are critical for host survival

Either a Th17 or a Th1 effector response can drive autoimmunity: conditions of disease induction affect dominant effector category

Experimental autoimmune uveitis (EAU) represents autoimmune uveitis in humans. We examined the role of the interleukin (IL)-23–IL-17 and IL-12–T helper cell (Th)1 pathways in the pathogenesis of EAU. IL–23 but not IL-12 was necessary to elicit disease by immunization with the retinal antigen (Ag) interphotoreceptor retinoid-binding protein (IRBP) in complete Freund's adjuvant. IL-17 played a dominant role in this model; its neutralization prevented or reversed disease, and Th17 effector cells induced EAU in the absence of interferon (IFN)-γ. In a transfer model, however, a polarized Th1 line could induce severe EAU independently of host IL-17. Furthermore, induction of EAU with IRBP-pulsed mature dendritic cells required generation of an IFN-γ–producing effector response, and an IL-17 response by itself was insufficient to elicit pathology. Finally, genetic deficiency of IL-17 did not abrogate EAU susceptibility. Thus, autoimmune pathology can develop in the context of either a Th17 or a Th1 effector response depending on the model. The data suggest that the dominant effector phenotype may be determined at least in part by conditions present during initial exposure to Ag, including the quality/quantity of Toll-like receptor stimulation and/or type of Ag-presenting cells. These data also raise the possibility that the nonredundant requirement for IL-23 in EAU may extend beyond its role in promoting the Th17 effector response and help provide a balance in the current Th1 versus Th17 paradigm

The helminth product, ES-62, protects against airway inflammation by resetting the Th cell phenotype

We previously demonstrated inhibition of ovalbumin (OVA)-induced allergic airway hyper-responsiveness in the mouse using ES-62, a phosphorylcholine-containing glycoprotein secreted by the filarial nematode, Acanthocheilonema viteae. This inhibition correlated with ES-62-induced mast cell desensitisation, although the degree to which this reflected direct targeting of mast cells remained unclear as suppression of the Th2 phenotype of the inflammatory response, as measured by eosinophilia and IL-4 levels in the lungs, was also observed. We now show that inhibition of the lung Th2 phenotype is reflected in ex vivo analyses of draining lymph node recall cultures and accompanied by a decrease in the serum levels of total and OVA-specific IgE. Moreover, ES-62 also suppresses the lung infiltration by neutrophils that is associated with severe asthma and is generally refractory to conventional anti-inflammatory therapies, including steroids. Protection against Th2-associated airway inflammation does not reflect induction of regulatory T cell (Treg) responses (there is no increased IL-10 or Foxp3 expression) but rather a switch in polarisation towards increased T-bet expression and IFNγ production. This ES-62-driven switch in the Th1/Th2 balance is accompanied by decreased IL-17 responses, a finding in line with reports that IFNγ and IL-17 are counter-regulatory. Consistent with ES-62 mediating its effects via IFNγ-mediated suppression of pathogenic Th2/Th17 responses, we found that neutralising anti-IFNγ antibodies blocked protection against airway inflammation in terms of pro-inflammatory cell infiltration, particularly by neutrophils and lung pathology. Collectively, these studies indicate that ES-62, or more likely small molecule analogues, could have therapeutic potential in asthma, in particular for those subtypes of patients (e.g. smokers, steroid-resistant) who are refractory to current treatments

A 'resource allocator' for transcription based on a highly fragmented T7 RNA polymerase

Synthetic genetic systems share resources with the host, including machinery for transcription and translation. Phage RNA polymerases (RNAPs) decouple transcription from the host and generate high expression. However, they can exhibit toxicity and lack accessory proteins (σ factors and activators) that enable switching between different promoters and modulation of activity. Here, we show that T7 RNAP (883 amino acids) can be divided into four fragments that have to be co‐expressed to function. The DNA‐binding loop is encoded in a C‐terminal 285‐aa ‘σ fragment’, and fragments with different specificity can direct the remaining 601‐aa ‘core fragment’ to different promoters. Using these parts, we have built a resource allocator that sets the core fragment concentration, which is then shared by multiple σ fragments. Adjusting the concentration of the core fragment sets the maximum transcriptional capacity available to a synthetic system. Further, positive and negative regulation is implemented using a 67‐aa N‐terminal ‘α fragment’ and a null (inactivated) σ fragment, respectively. The α fragment can be fused to recombinant proteins to make promoters responsive to their levels. These parts provide a toolbox to allocate transcriptional resources via different schemes, which we demonstrate by building a system which adjusts promoter activity to compensate for the difference in copy number of two plasmids.United States. Office of Naval Research (N00014‐13‐1‐0074)National Institutes of Health (U.S.) (5R01GM095765)National Science Foundation (U.S.) (Synthetic Biology Engineering Research Center (SA5284‐11210))United States. Dept. of Defense (National Defense Science and Engineering Graduate Fellowship (NDSEG) Program))Hertz Foundation (Fellowship

Low CD4/CD8 T-Cell Ratio Associated with Inflammatory Arthropathy in Human T-Cell Leukemia Virus Type I Tax Transgenic Mice

Human T-cell leukemia virus type I (HTLV-1) can cause an aggressive malignancy known as adult T-cell leukemia/lymphoma (ATL) as well as inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). A transgenic mouse that expresses HTLV-1 Tax also develops T-cell leukemia/lymphoma and an inflammatory arthropathy that resembles rheumatoid arthritis. The aim of this study was to identify the primary T-cell subsets involved in the development of arthropathy in Tax transgenic mice. mRNA was strong in the spleen and joints of arthropathic mice, with a 40-fold increase compared with healthy transgenic mice.Our findings reveal that Tax transgenic mice develop rheumatoid-like arthritis with proliferating synovial cells in the joints; however, the proportion of different splenic T-cell subsets in these mice was completely different from other commonly used animal models of rheumatoid arthritis. The crucial T-cell subsets in arthropathic Tax transgenic mice appear to resemble those in HAM/TSP patients rather than those in rheumatoid arthritis patients

IL-23 suppresses innate immune response independently of IL-17A during carcinogenesis and metastasis

IL-23 is an important molecular driver of Th17 cells and has strong tumor-promoting proinflammatory activity postulated to occur via adaptive immunity. Conversely, more recently it has been reported that IL-17A elicits a protective inflammation that promotes the activation of tumor-specific CD8(+) T cells. Here we show the much broader impact of IL-23 in antagonizing antitumor immune responses primarily mediated by innate immunity. Furthermore, the majority of this impact was independent of IL-17A, which did not appear critical for many host responses to tumor initiation or metastases. IL-23-deficient mice were resistant to experimental tumor metastases in three models where host NK cells controlled disease. Immunotherapy with IL-2 was more effective in mice lacking IL-23, and again the protection afforded was NK cell mediated and independent of IL-17A. Further investigation revealed that loss of IL-23 promoted perforin and IFN-gamma antitumor effector function in both metastasis models examined. IL-23-deficiency also strikingly protected mice from tumor formation in two distinct mouse models of carcinogenesis where the dependence on host IL-12p40 and IL-17A was quite different. Notably, in the 3'-methylcholanthrene (MCA) induction of fibrosarcoma model, this protection was completely lost in the absence of NK cells. Overall, these data indicate the general role that IL-23 plays in suppressing natural or cytokine-induced innate immunity, promoting tumor development and metastases independently of IL-17A

CARD9⁺ microglia promote antifungal immunity via IL-1β- and CXCL1-mediated neutrophil recruitment

This work was supported by the Intramural Research Program of the National Institute of Allergy and Infectious Disease, National Institutes of Health, as well as NIH grants awarded to TMH (R01 093808), SGF (R01AI124566) and SRL (R01CA161373). Additional funding was provided by the Burroughs Wellcome Fund (awarded to TMH), the Wellcome Trust (102705, 097377; awarded to GDB), the MRC Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1; awarded to GDB). The authors additionally thank Celeste Huaman for care and screening of the Malt1 793 -/- mice.Peer reviewedPostprin