Project description:Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disorder of the central nervous system (CNS). Current therapies mainly target inflammatory processes during acute stages, but effective treatments for progressive MS are limited. In this context, astrocytes have gained increasing attention as they have the capacity to drive, but also suppress tissue-degeneration. Here we show that astrocytes upregulate the immunomodulatory checkpoint molecule PD-L1 during acute autoimmune CNS inflammation in response to aryl hydrocarbon receptor and interferon signaling. Using CRISPR-Cas9 genetic perturbation in combination with small-molecule and antibody-mediated inhibition of PD-L1 and PD-1 both in vivo and in vitro, we demonstrate that astrocytic PD-L1 and its interaction with microglial PD-1 is required for the attenuation of autoimmune CNS inflammation in acute and progressive stages in a mouse model of MS. Our findings suggest the glial PD-L1 / PD-1 axis as a new therapeutic target for both acute and progressive MS stages.
Project description:Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disorder of the central nervous system (CNS). Current therapies mainly target inflammatory processes during acute stages, but effective treatments for progressive MS are limited. In this context, astrocytes have gained increasing attention as they have the capacity to drive, but also suppress tissue-degeneration. Here we show that astrocytes upregulate the immunomodulatory checkpoint molecule PD-L1 during acute autoimmune CNS inflammation in response to aryl hydrocarbon receptor and interferon signaling. Using CRISPR-Cas9 genetic perturbation in combination with small-molecule and antibody-mediated inhibition of PD-L1 and PD-1 both in vivo and in vitro, we demonstrate that astrocytic PD-L1 and its interaction with microglial PD-1 is required for the attenuation of autoimmune CNS inflammation in acute and progressive stages in a mouse model of MS. Our findings suggest the glial PD-L1 / PD-1 axis as a new therapeutic target for both acute and progressive MS stages.
Project description:To systematically characterize anti-PD-1/PD-L1 immunotherapy-related changes in serum glycoproteins and discover novel biomarkers related to treatment response, we analyzed a series of sera samples from patients with metastatic lung squamous cell carcinoma (SCC) and lung adenocarcinoma (ADC), collected before and during ICIs treatment, with mass-spectrometry-based label-free quantification methodology.
Project description:Ischemic stroke is a common acute CNS disorder leading to nearly half a million deaths per year in Europe. The high mortality is primarily owed to the limited treatment options of restoring blood flow in a narrow time window of several hours. Furthermore, inflammatory processes in the days and weeks after ischemic stroke contribute to tissue loss and neurological deficits. The key cells that influence and control this inflammatory cascade are microglia, the innate immune cells of the CNS. Microglia can be influenced and activated by e.g. lipopolysaccharide (LPS),a bacterial cell membrane component. It has been previously shown, that repetitive LPS stimuli prior to infarction (termed immunological preconditioning) lead to reduced infarct volumina in mouse models of ischemic stroke. Furthermore, our laboratory has shown, that phosphoinositide-3 kinase gamma mediates microglial functions after LPS-preconditioning. Hence, the aim of this work was to characterize proteomic alterations in microglia with (I) ischemic stroke in general in the tMCAO (transient middle cerebral artery occlusion) mouse model of ischemic stroke, (II) the influence of LPS-preconditioning on microglial proteomic alterations after tMCAO and (III) the role of PI3Ky in the microglial proteomic changes after tMCAO and preconditioning. This was done by a single LPS injection 3 days before tMCAO in wildtype mice and mice with PI3Ky knockout or knockin of the kinase dead form of PI3Ky.
Project description:Abnormal accumulation of aggregated proteins and sustained microglial activation are important contributors of neurodegenerative process in neurological diseases. Recent studies have shown that aggregation-prone proteins, such as a-synuclein, the protein implicated in Parkinson’s disease (PD), are released from neuronal cells and thus present in the extracellular fluid, pointing to the possible paracrine effects of these proteins on microglial immune responses. However, the mechanism underlying the disease-associated microglial activation and the role of neuronal proteins in this process remain unknown. Here, we show that extracellular a-synuclein released from neuronal cells is an endogenous ligand of toll-like receptor 2 (TLR2) and activates microglia, which in turn induces neurodegeneration. Interaction between neuron-released a-synuclein and TLR2 and subsequent activation of the TLR2 signaling were demonstrated comprehensively by using computational modeling of signaling network and by the experimental validation in TLR2-deficient microglia both in vitro and in vivo. In contrast to the neuron-released a-synuclein, recombinant a-synuclein proteins, including monomer, oligomer, fibril, or nitrated forms, were not able to interact or activate TLR2, suggesting that neuronal cells have a mechanism of enriching specific forms of a-synuclein capable of activating TLR2 during the process of releasing this protein. Taken together, the results suggest that both neuron-released extracellular a-synuclein and TLR2 might be novel therapeutic targets for modifying neuroinflammation in PD and related neurodegenerative diseases. We collected culture media from differentiated SH-SY5Y cells overexpressing either human a-synuclein (alpha-SCM) or beta-galactosidase (LZCM) and treat these media to primary rat microglia at the concentration of a-synuclein of 1.1M. Transcriptome analyses with microglial cells treated with either aSCM or LZCM at two different time points, 6 h and 24 h.
Project description:Colorectal cancer is the second leading cause of cancer mortality in the US. Although immune checkpoint blockade therapies such as anti-PD-1/PD-L1 have had successes in some patients, the response rate is still low. We have found that riluzole, a well-tolerated FDA-approved oral medicine for treating amyotrophic lateral sclerosis, increased intratumoral CD8+ T cells and suppressed tumor growth of colon cancer cells in syngeneic immune competent mice. Riluzole-mediated tumor suppression was dependent on the presence of CD8+ T cells. Riluzole activates the cytosolic DNA sensing cGAS/STING pathway and increases expression of interferon β (IFNβ) and IFNβ-regulated genes including CXCL10. Inhibition of ATM, but not ATR, results in a synergistic increase in IFNβ expression, suggesting that riluzole-dependent double strand breaks contribute to cGAS/STING activation. Knockout of cGAS or STING significantly attenuated expression of IFNβ and CXCL10 and nearly abolished suppression of tumor growth. Riluzole failed to increase intratumoral CD8+ T cells in STING knockout tumors. These results indicate that riluzole recruits CD8+ T cells into the tumor microenvironment through tumor cell intrinsic STING activation. When riluzole was combined with a PD-1 antibody, the treatment was more effective in suppressing tumor growth in vivo. Taken together, our studies indicate that riluzole inhibits tumor growth through the activation of cGAS/STING signaling and may increase the efficacy of anti-PD-1/PD-L1 therapies in colon cancer.
Project description:Astrocytic secretion of soluble B7-H1 and subsequent engagement with microglial PD-1 regulates microglial clearance of Ab by modulating the expression of CD36.
Project description:A murine gastric cancer YTN16 is sensitive to anti-CTLA-4, but resistant to anti-PD-L1. To investigate tumor microenvironments after treatment of these mAbs, we performed RNA-Seq analyses.