Target prioritization is essential for drug discovery and repositioning. Applying computational methods to analyze and process multi-omics data to find new drug targets is a practical approach for achieving this. Despite an increasing number of methods for generating datasets such as genomics, phenomics, and proteomics, attempts to integrate and mine such datasets remain limited in scope.
View Article and Find Full Text PDFDysregulated sensing of self-nucleic acid is a leading cause of autoimmunity in multifactorial and monogenic diseases. Mutations in Wiskott-Aldrich syndrome protein (WASp), a key regulator of cytoskeletal dynamics in immune cells, cause autoimmune manifestations and increased production of type I IFNs by innate cells. Here we show that immune complexes of self-DNA and autoantibodies (DNA-ICs) contribute to elevated IFN levels via activation of the cGAS/STING pathway of cytosolic sensing.
View Article and Find Full Text PDFNonclassical monocytes maintain vascular homeostasis by patrolling the vascular endothelium, responding to inflammatory signals, and scavenging cellular debris. Nonclassical monocytes also prevent metastatic tumor cells from seeding new tissues, but whether the patrolling function of nonclassical monocytes is required for this process is unknown. To answer this question, we utilized an inducible-knockout mouse that exhibits loss of the integrin-adaptor protein Kindlin-3 specifically in nonclassical monocytes.
View Article and Find Full Text PDFEfficacious use of therapeutic gene delivery via nanoparticles is hampered by the challenges associated with targeted delivery to tissues of interest. Systemic administration of lipid nanoparticle (LNP)-encapsulated mRNA leads to a protein expressed predominantly in the liver and spleen. Here, LNP encapsulating mRNA was covalently conjugated to an antibody, specifically binding plasmalemma vesicle-associated protein (PV1) as a means to target lung tissue.
View Article and Find Full Text PDFTargeted strategies to deliver and retain drugs to kidneys are needed to improve drug accumulation and efficacy in a myriad of kidney diseases. These drug delivery systems show potential for improving the therapeutic windows of drugs acting in the kidney. Biodistribution of antibody-based therapeutics in vivo is governed by several factors including binding affinity, size, and valency.
View Article and Find Full Text PDFSystemic administration of bio-therapeutics can result in only a fraction of drug reaching targeted tissues, with the majority of drug being distributed to tissues irrelevant to the drug's site of action. Targeted delivery to specific organs may allow for greater accumulation, better efficacy, and improved safety. We investigated how targeting plasmalemma vesicle-associated protein (PV1), a protein found in the endothelial caveolae of lungs and kidneys, can promote accumulation in these organs.
View Article and Find Full Text PDFObjective: We investigated the mechanistic and pharmacological properties of anifrolumab, a fully human, effector-null, anti-type I interferon (IFN) alpha receptor 1 (IFNAR1) monoclonal antibody in development for SLE.
Methods: IFNAR1 surface expression and internalisation on human monocytes before and after exposure to anifrolumab were assessed using confocal microscopy and flow cytometry. The effects of anifrolumab on type I IFN pathway activation were assessed using signal transducer and activator of transcription 1 (STAT1) phosphorylation, IFN-stimulated response element-luciferase reporter cell assays and type I IFN gene signature induction.
Uncontrolled secretion of type I IFN, as the result of endosomal TLR (i.e., TLR7 and TLR9) signaling in plasmacytoid DCs (pDCs), and abnormal production of autoantibodies by B cells are critical for systemic lupus erythematosus (SLE) pathogenesis.
View Article and Find Full Text PDFMononuclear phagocytes are a heterogeneous family that occupy all tissues and assume numerous roles to support tissue function and systemic homeostasis. Our ability to dissect the roles of individual subsets is limited by a lack of technologies that ablate gene function within specific mononuclear phagocyte sub-populations. Using Nr4a1-dependent Ly6C monocytes, we present a proof-of-principle approach that addresses these limitations.
View Article and Find Full Text PDFExtracellular tumor material including exosomes, microvesicles and apoptotic tumor debris may help cancers invade new organs. Enhancing the removal of extracellular tumor material by immune cells represents a novel immunotherapy approach for preventing cancer metastasis. This protocol quantifies the uptake and removal of extracellular tumor material from circulation and tissues by immune cells.
View Article and Find Full Text PDFImmunotherapy has demonstrated great therapeutic potential by activating the immune system to fight cancer. However, little is known about the specific dynamics of interactions that occur between tumor and immune cells. In this protocol we describe a novel method to visualize the interaction of tumor and immune cells in the lung of live mice, which can be applied to other organs.
View Article and Find Full Text PDFThe molecular mechanisms that link the sympathetic stress response and inflammation remain obscure. Here we found that the transcription factor Nr4a1 regulated the production of norepinephrine (NE) in macrophages and thereby limited experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Lack of Nr4a1 in myeloid cells led to enhanced NE production, accelerated infiltration of leukocytes into the central nervous system (CNS) and disease exacerbation in vivo.
View Article and Find Full Text PDFThe immune system plays an important role in regulating tumor growth and metastasis. Classical monocytes promote tumorigenesis and cancer metastasis, but how nonclassical "patrolling" monocytes (PMo) interact with tumors is unknown. Here we show that PMo are enriched in the microvasculature of the lung and reduce tumor metastasis to lung in multiple mouse metastatic tumor models.
View Article and Find Full Text PDFTissue macrophages function to maintain homeostasis and regulate immune responses. While tissue macrophages derive from one of a small number of progenitor programs, the transcriptional requirements for site-specific macrophage subset development are more complex. We have identified a new tissue macrophage subset in the thymus and have discovered that its development is dependent on transcription factor NR4A1.
View Article and Find Full Text PDFArterioscler Thromb Vasc Biol
June 2015
Nonclassical patrolling monocytes are characterized by their unique ability to actively patrol the vascular endothelium under homeostatic and inflammatory conditions. Patrolling monocyte subsets (CX3CR1(high)Ly6C(-) in mouse and CX3CR1(high)CD14(dim)CD16(+) in humans) are distinct from the classical monocyte subsets (CCR2(high)Ly6C(+) in mouse and CCR2(high)CD14(+)CD16(-) in humans) and exhibit unique functions in the vasculature and inflammatory disease. Patrolling monocytes function in several disease settings to remove damaged cells and debris from the vasculature and have been associated with wound healing and the resolution of inflammation in damaged tissues.
View Article and Find Full Text PDFStress has long been thought to be a major contributing factor to cardiovascular disease, although little is known about the underlying cellular mechanisms. A new study illustrates that chronic stress promotes hematopoietic stem cell proliferation in bone marrow, leading to increased leukocyte production, circulation, and recruitment to the vasculature.
View Article and Find Full Text PDFPurpose Of Review: To understand chronic inflammatory diseases such as atherosclerosis, we require in-depth knowledge on immune-cell differentiation, function of specific immune-cell subsets and endothelial cell-mediated extravasation. In this review, we summarize a number of very recent observations on the pivotal function of NR4A nuclear receptors in immunity and atherosclerosis.
Recent Findings: NR4A nuclear receptors are involved in negative selection of thymocytes, Treg differentiation and the development of Ly6C monocytes.
Gammadelta (γδ) T lymphocytes respond quickly upon antigen encounter to produce a cytokine response. In this study, we sought to understand how functions of γδ T cells are differentially regulated compared to αβ T cells. We found that cholesterol, an integral component of the plasma membrane and a regulator of TCR signaling, is increased in γδ T cells compared to αβ T cells, and modulates their function.
View Article and Find Full Text PDFThe functions of Nr4a1-dependent Ly6C(low) monocytes remain enigmatic. We show that they are enriched within capillaries and scavenge microparticles from their lumenal side in a steady state. In the kidney cortex, perturbation of homeostasis by a TLR7-dependent nucleic acid "danger" signal, which may signify viral infection or local cell death, triggers Gαi-dependent intravascular retention of Ly6C(low) monocytes by the endothelium.
View Article and Find Full Text PDFBackground: Stem cells are thought to enhance vascular remodeling in ischemic tissue in part through paracrine effects. Using molecular imaging, we tested the hypothesis that treatment of limb ischemia with multipotential adult progenitor cells (MAPCs) promotes recovery of blood flow through the recruitment of proangiogenic monocytes.
Methods And Results: Hind-limb ischemia was produced in mice by iliac artery ligation, and MAPCs were administered intramuscularly on day 1.
Rationale: NR4A1 (Nur77) is a nuclear receptor that is expressed in macrophages and within atherosclerotic lesions, yet its function in atherosclerosis is unknown.
Objective: Nur77 regulates the development of monocytes, particularly patrolling Ly6C(-) monocytes that may be involved in resolution of inflammation. We sought to determine how absence of nuclear receptor subfamily 4, group A, member 1 (NR4A1) in hematopoietic cells affected atherosclerosis development.
The transcription factors that regulate differentiation into the monocyte subset in bone marrow have not yet been identified. Here we found that the orphan nuclear receptor NR4A1 controlled the differentiation of Ly6C- monocytes. Ly6C- monocytes, which function in a surveillance role in circulation, were absent from Nr4a1-/- mice.
View Article and Find Full Text PDFBoth membrane progestin receptors (mPRs) and the nuclear progestin receptor (nPR or Pgr) decode the non-genomic progestin signaling (NGPS) in vertebrates. However, the receptor for deciphering extracellular NGPS and initiating meiosis resumption in vertebrate oocytes is still contested hotly. We studied the roles of nPR and mPRs by determining their localization, changes of expression, and activation of NGPS during final oocyte maturation (FOM) in zebrafish.
View Article and Find Full Text PDFThe zebrafish nuclear progestin receptor (nPR; official symbol PGR) was identified and characterized to better understand its role in regulating reproduction in this well-established teleost model. A full-length cDNA was identified that encoded a 617-amino acid residue protein with high homology to PGRs in other vertebrates, and contained five domains characteristic of nuclear steroid receptors. In contrast to the multiplicity of steroid receptors often found in euteleosts and attributed to probable genome duplication, only a single locus encoding the full-length zebrafish pgr was identified.
View Article and Find Full Text PDF