Double-stranded DNA activates glomerular endothelial cells and enhances albumin permeability via a toll-like receptor-independent cytosolic DNA recognition pathway.
Viral DNA induces potent antiviral immunity by activating dendritic cells; however, the mechanism governing viral DNA-mediated triggering or aggravation of glomerulonephritis is unknown. Glomerular endothelial cells (GEnCs) do not express toll-like receptor (TLR)9, the only DNA-specific TLR. We therefore hypothesized that DNA could activate GEnCs via the recently discovered TLR-independent viral DNA recognition pathway. Indeed, double-stranded non-CpG (B-) DNA activated GEnCs to produce interleukin-6, CCL5/RANTES, CCL2/MCP-1, CXCL10/IP10, interferon (IFN)-alpha, and IFN-beta when cationic lipids facilitated intracellular DNA uptake. This cytokine production was inhibited by chlorpromazine, suggesting that clathrin-dependent endocytosis is required for B-DNA entry. However, chloroquine and MyD88 inhibition did not affect GEnC activation, suggesting TLR-independent DNA recognition. In addition, IFN-beta activated cytokine and chemokine mRNA expression, although only CXCL10/IP10 was induced at the protein level, and type I IFN did not activate GEnC in an autocrine-paracrine auto-activation loop. B-DNA complexes induced intercellular adhesion molecule-1 expression at the GEnC surface and increased intercellular adhesion molecule-1-dependent leukocyte adhesion and microvascular extravasation in vivo. Furthermore, B-DNA complexes increased albumin permeability of GEnC monolayers in culture or microvascular dextran leakage in vivo. In addition, B-DNA complexes impaired GEnC proliferation. Thus, complexed B-DNA activates GEnC to produce cytokines, chemokines, and type I IFNs, increases leukocyte adhesion and microvascular permeability, and reduces GEnC proliferation via a MyD88-independent cytosolic DNA recognition pathway. This innate antiviral response program suggests a novel pathomechanism regulating DNA virus-mediated induction or aggravation of glomerulonephritis.
Hägele
Holger
H
Department of Nephrology, University of Munich, Germany.
Allam
Ramanjaneyulu
R
Pawar
Rahul D
RD
Reichel
Christoph A
CA
Krombach
Fritz
F
Anders
Hans-Joachim
HJ
D000818:Animals; D002199:Capillary Permeability / Q000502:physiology*; D002448:Cell Adhesion; D002450:Cell Communication / Q000502:physiology; D018925:Chemokines / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D004247:DNA / Q000276:immunology*; D004279:DNA, Viral / Q000276:immunology; D004705:Endocytosis / Q000502:physiology; D011992:Endosomes / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000276:immunology / Q000502:physiology*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007370:Interferon Type I / Q000276:immunology; D007678:Kidney Glomerulus / Q000166:cytology / Q000378:metabolism; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism; D051379:Mice; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D034622:RNA Interference; D012709:Serum Albumin / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D051193:Toll-Like Receptors / Q000235:genetics / Q000276:immunology*
D018925:Chemokines; D016207:Cytokines; D004279:DNA, Viral; D007370:Interferon Type I; D053594:Myeloid Differentiation Factor 88; D012709:Serum Albumin; D051193:Toll-Like Receptors; D018799:Intercellular Adhesion Molecule-1; D004247:DNA