title: Exosomes from HIV-1-infected Cells Stimulate Production of Pro-inflammatory Cytokines through Trans-activating Response (TAR) RNA.
abstract: HIV-1 infection results in a chronic illness because long-term highly active antiretroviral therapy can lower viral titers to an undetectable level. However, discontinuation of therapy rapidly increases virus burden. Moreover, patients under highly active antiretroviral therapy frequently develop various metabolic disorders, neurocognitive abnormalities, and cardiovascular diseases. We have previously shown that exosomes containing trans-activating response (TAR) element RNA enhance susceptibility of undifferentiated naive cells to HIV-1 infection. This study indicates that exosomes from HIV-1-infected primary cells are highly abundant with TAR RNA as detected by RT-real time PCR. Interestingly, up to a million copies of TAR RNA/μl were also detected in the serum from HIV-1-infected humanized mice suggesting that TAR RNA may be stable in vivo. Incubation of exosomes from HIV-1-infected cells with primary macrophages resulted in a dramatic increase of proinflammatory cytokines, IL-6 and TNF-β, indicating that exosomes containing TAR RNA could play a direct role in control of cytokine gene expression. The intact TAR molecule was able to bind to PKR and TLR3 effectively, whereas the 5' and 3' stems (TAR microRNAs) bound best to TLR7 and -8 and none to PKR. Binding of TAR to PKR did not result in its phosphorylation, and therefore, TAR may be a dominant negative decoy molecule in cells. The TLR binding through either TAR RNA or TAR microRNA potentially can activate the NF-κB pathway and regulate cytokine expression. Collectively, these results imply that exosomes containing TAR RNA could directly affect the proinflammatory cytokine gene expression and may explain a possible mechanism of inflammation observed in HIV-1-infected patients under cART.
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110.
authors.forename: Gavin C
authors.initials: GC
authors.lastname: Sampey
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Saifuddin
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110.
authors.forename: Angela
authors.initials: A
authors.lastname: Schwab
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110.
authors.forename: Robert
authors.initials: R
authors.lastname: Barclay
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110.
authors.forename: Shreya
authors.initials: S
authors.lastname: Punya
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110.
authors.forename: Myung-Chul
authors.initials: MC
authors.lastname: Chung
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110.
authors.forename: Ramin M
authors.identifier: http://orcid.org/0000-0001-7122-0164
authors.initials: RM
authors.lastname: Hakami
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110.
authors.forename: Mohammad Asad
authors.initials: MA
authors.lastname: Zadeh
authors.affiliation: Ceres Nanosciences Inc., Manassas, Virginia 20110.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Lepene
authors.affiliation: the Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104.
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Klase
authors.affiliation: the Department of Immunology, Herbert Wertheim College of Medicine, Miami, Florida 33199, and.
authors.forename: Nazira
authors.initials: N
authors.lastname: El-Hage
authors.affiliation: the Department of Medicine, Women's Intra-Agency HIV Study, Georgetown University, Washington, D. C. 20007.
authors.forename: Mary
authors.initials: M
authors.lastname: Young
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110, siordans@gmu.edu.
authors.forename: Sergey
authors.initials: S
authors.lastname: Iordanskiy
authors.affiliation: From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110, fkashanc@gmu.edu.
authors.forename: Fatah
authors.initials: F
authors.lastname: Kashanchi
mesh_terms: D051696:Activating Transcription Factors / Q000378:metabolism*; D021581:Active Transport, Cell Nucleus; D000818:Animals; D002460:Cell Line; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D055354:Exosomes / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D015658:HIV Infections / Q000097:blood / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D007962:Leukocytes / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D008233:Lymphotoxin-alpha / Q000378:metabolism; D016688:Mice, Inbred NOD; D008822:Mice, Transgenic; D035683:MicroRNAs / Q000097:blood / Q000378:metabolism*; D051196:Toll-Like Receptor 3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D019892:eIF-2 Kinase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D051696:Activating Transcription Factors; D016207:Cytokines; C508600:IL6 protein, human; D015850:Interleukin-6; D008233:Lymphotoxin-alpha; D035683:MicroRNAs; C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3; D019892:eIF-2 Kinase
keywords: TAR RNA; cytokinesis; exosome (vesicle); human immunodeficiency virus (HIV); macrophage; protein kinase RNA-activated (PKR); toll-like receptor (TLR)