Type I and Type III Interferons Display Different Dependency on Mitogen-Activated Protein Kinases to Mount an Antiviral State in the Human Gut

Intestinal epithelial cells (IECs) are constantly exposed to commensal flora and pathogen challenges. How IECs regulate their innate immune response to maintain gut homeostasis remains unclear. Interferons (IFNs) are cytokines produced during infections. While type I IFN receptors are ubiquitously expressed, type III IFN receptors are expressed only on epithelial cells. This epithelium specificity strongly suggests exclusive functions at epithelial surfaces, but the relative roles of type I and III IFNs in the establishment of an antiviral innate immune response in human IECs are not clearly defined. Here, we used mini-gut organoids to define the functions of types I and III IFNs to protect the human gut against viral infection. We show that primary non-transformed human IECs, upon viral challenge, upregulate the expression of both type I and type III IFNs at the transcriptional level but only secrete type III IFN in the supernatant. However, human IECs respond to both type I and type III IFNs by producing IFN-stimulated genes that in turn induce an antiviral state. Using genetic ablation of either type I or type III IFN receptors, we show that either IFN can independently restrict virus infection in human IECs. Importantly, we report, for the first time, differences in the mechanisms by which each IFN establishes the antiviral state. Contrary to type I IFN, the antiviral activity induced by type III IFN is strongly dependent on the mitogen-activated protein kinases signaling pathway, suggesting a pathway used by type III IFNs that non-redundantly contributes to the antiviral state. In conclusion, we demonstrate that human intestinal epithelial cells specifically regulate their innate immune response favoring type III IFN-mediated signaling, which allows for efficient protection against pathogens without producing excessive inflammation. Our results strongly suggest that type III IFN constitutes the frontline of antiviral response in the human gut. We propose that mucosal surfaces, particularly the gastrointestinal tract, have evolved to favor type III IFN-mediated response to pathogen infections as it allows for spatial segregation of signaling and moderate production of inflammatory signals which we propose are key to maintain gut homeostasis.

Zur Kenntnis des ersten Alkalimetall-Cadmium-Halogeno-Oxovanadats: K4CdV5O15Cl / On the First Alkaline-Cadmium-Vanadium Oxide Halide: K4CdV5O15Cl

Single crystals of K4CdV5O15Cl have been prepared by crystallization from melts. The yellow crystals show tetragonal symmetry, space group C1 4-P4, a = 9.097(1), c = 5.331(2) Å, Z = 1. K4CdV5O15Cl belongs to the K4CuV5O3Cl type. V (l) forms V2O7 double tetrahedra connected by square V(2)O5 pyramids and CdO4Cl2 octahedra. The crystal structure is dis­cussed with respect to the isotypic compound K4CuV5O15Cl considering a short V(2)-O distance indicative of a vanadinyl group.

Cd0,73Cu0,27V2O6: Eine Verbindung mit Branneritstruktur / Cd0 ,73Cu0,27V2O6: A Compound with Brannerite Structure

Single crystals of Cd0.73Cu0.27V2O6 were prepared by solid state reactions. X-ray investigations lead to monoclinic symmetry, space group C3 2h-C2/m , a = 9.339, b = 3.5604, c = 6.893 Å, β = 111.85°, Z = 2. It belongs to the Brannerite structure, showing a statistical distribution of Cd2+ and Cu2+ on one point position. The crystal structure of Brannerites is discussed with respect to the distorted O2- octahedra around V5+ and the influence of the Jahn-Teller active Cu2+ ion to the shortened M2+O6 octahedra.

Kristallstrukturuntersuchung des Kupfer-Cadmium-Oxovanadats CuCdVO4 / Crystal Structure Investigation of the Copper Cadmium Oxovanadate CuCdVO4

Single crystals of CuCdVO4 have been prepared by CO2-LASER techniques. X -ray investigations of the black single crystals led to orthorhombic symmetry, space group D2h 17-Cmcm , a = 5.921(1), b = 9.065(4), c = 6.633(2) Å, Z = 4. CuCdVO4 represents the first example of a quaternary oxide containing cadmium and copper(I). Compared to AgCdVO4, CuCdVO4 shows a different linkage of the VO4 and CuO4 tetrahedra, explaining the missing isotypy of these com pounds.

Zur Kristallchemie eines Silber-Cadmium-Oxovanadats: AgCdVO4 / On the Crystal Chemistry of a Silver Cadmium Oxovanadate: AgCdVO4

Single crystals of AgCdVO4 have been prepared in closed silver tubes using V2O5 as a flux. The light-orange crystals show orthorhombic symmetry, space group D16 2h-Pnma, a = 9.786(2), b = 6.994(1), c = 5.439(1) Å, Z = 4. The hitherto unknown AgCdVO4 is related to the Olivine structure but isotypic to Ag2CrO4 and NaCd4(VO4)3 respectively. The differences in crystal chemistry between the Olivine type, NaCd4(VO4)3 and AgCdVO4 are discussed.

Ein Cadmium-Kupfer-Phosphat mit einfach überkappten trigonalen CdO6-Prismen-Netzen: Cd1.35Cu1.65(PO4)2

Single crystals of Cd1.35Cu1.65(PO4)2 have been prepared by solid state reactions below the melting point of the starting compounds. The light green crystals crystallize with monoclinic symmetry, space group C5 2h-P21/c , a = 9.062(2), b = 11.669(2), c = 5.950(2) Å , β = 97.88(2)°, Z = 4. Cd1.35Cu1.65(PO4)2 shows relationship to the mineral graftonite. The crystal structure is characterized by nets of corner connected Cd2O12 polyhedra. One point position is statistically occupied by Cd2+ and Cu2+ ions.