Modulation of occluding junctions alters the hematopoietic niche to trigger immune activation
نویسندگان
چکیده
Stem cells are regulated by signals from their microenvironment, or niche. During Drosophila hematopoiesis, a niche regulates prohemocytes to control hemocyte production. Immune challenges activate cell-signalling to initiate the cellular and innate immune response. Specifically, certain immune challenges stimulate the niche to produce signals that induce prohemocyte differentiation. However, the mechanisms that promote prohemocyte differentiation subsequent to immune challenges are poorly understood. Here we show that bacterial infection induces the cellular immune response by modulating occluding-junctions at the hematopoietic niche. Occluding-junctions form a permeability barrier that regulates the accessibility of prohemocytes to niche derived signals. The immune response triggered by infection causes barrier breakdown, altering the prohemocyte microenvironment to induce immune cell production. Moreover, genetically induced barrier ablation provides protection against infection by activating the immune response. Our results reveal a novel role for occluding-junctions in regulating niche-hematopoietic progenitor signalling and link this mechanism to immune cell production following infection.
منابع مشابه
Occluding Junctions Maintain Stem Cell Niche Homeostasis in the Fly Testes
Stem cells can be controlled by their local microenvironment, known as the stem cell niche. The Drosophila testes contain a morphologically distinct niche called the hub, composed of a cluster of between 8 and 20 cells known as hub cells, which contact and regulate germline stem cells (GSCs) and somatic cyst stem cells (CySCs). Both hub cells and CySCs originate from somatic gonadal precursor c...
متن کاملتاثیر آشیانههای جفتی شبیهسازی شده با داربست پلی لاکتیک اسید در تکثیر سلولهای بنیادی خونساز مشتق از بافت جفت انسانی
Background and Objective: Nowadays, although umbilical cord blood is a commonly used source of hematopoietic stem cell, its low frequency of these cells is the main factor limiting its clinical application. The transplantation of hematopoietic stem cells derived from placenta tissue along with umbilical cord blood cells of the same sample may be an appropriate approach to solve this problem. In...
متن کاملRhythmic Modulation of the Hematopoietic Niche through Neutrophil Clearance
Unique among leukocytes, neutrophils follow daily cycles of release from and migration back into the bone marrow, where they are eliminated. Because removal of dying cells generates homeostatic signals, we explored whether neutrophil elimination triggers circadian events in the steady state. Here, we report that the homeostatic clearance of neutrophils provides cues that modulate the physiology...
متن کاملReactive oxygen species-dependent Toll/NF-κB activation in the Drosophila hematopoietic niche confers resistance to wasp parasitism
Hematopoietic stem/progenitor cells in the adult mammalian bone marrow ensure blood cell renewal. Their cellular microenvironment, called 'niche', regulates hematopoiesis both under homeostatic and immune stress conditions. In the Drosophila hematopoietic organ, the lymph gland, the posterior signaling center (PSC) acts as a niche to regulate the hematopoietic response to immune stress such as ...
متن کاملSTAT3 as a Key Factor in Tumor Microenvironment and Cancer Stem Cell
Background Recent studies revealed that tumor-associated macrophages (TAMs) play a decisive role in the regulation of tumor progression by manipulating tumor oncogenesis, angiogenesis and immune functions within tumor microenvironments. Signal transducer and activator of transcription 3 (STAT3), which is a point of convergence for numerous oncogenic signalling pathways, is constitutively activ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 6 شماره
صفحات -
تاریخ انتشار 2017