153
Views
21
CrossRef citations to date
0
Altmetric
Review

Development of treatment strategies to combat Ebola and Marburg viruses

&
Pages 67-76 | Published online: 10 Jan 2014

References

  • Sullivan NJ, Sanchez A, Rollin PE, Yang ZY, Nabel GJ. Development of a preventive vaccine for Ebola virus infection in primates. Nature 408(6812), 605–609 (2000).
  • Sullivan NJ, Geisbert TW, Geisbert JB et al. Accelerated vaccination for Ebola virus haemorrhagic fever in non-human primates. Nature 424(6949), 681–684 (2003).
  • Jones SM, Feldmann H, Stroher U et al. Live attenuated recombinant vaccine protects nonhuman primates against Ebola and Marburg viruses. Nature Med. 11(7), 786–790 (2005).
  • Bray M. Defense against filoviruses used as biological weapons. Antiviral Res. 57(1–2), 53–60 (2003).
  • World Health Organization. Ebola haemorrhagic fever. Wkly Epidemiol. Rec. 70(34), 241–242 (1995).
  • Guimard Y, Bwaka MA, Colebunders R et al. Organization of patient care during the Ebola hemorrhagic fever epidemic in Kikwit, Democratic Republic of the Congo, 1995. J. Infect. Dis. 179(Suppl. 1), S268–S273 (1999).
  • Trexler PC, Emond RT, Evans B. Negative-pressure plastic isolator for patients with dangerous infections. Br. Med. J. 2(6086), 559–561 (1977).
  • Theriault S, Groseth A, Neumann G, Kawaoka Y, Feldmann H. Rescue of Ebola virus from cDNA using heterologous support proteins. Virus Res. 106(1), 43–50 (2004).
  • Towner JS, Paragas J, Dover JE et al. Generation of eGFP expressing recombinant Zaire ebolavirus for analysis of early pathogenesis events and high-throughput antiviral drug screening. Virology 332(1), 20–27 (2005).
  • Volchkov VE, Volchkova VA, Muhlberger E et al. Recovery of infectious Ebola virus from complementary DNA: RNA editing of the GP gene and viral cytotoxicity. Science 291(5510), 1965–1969 (2001).
  • Neumann G, Feldmann H, Watanabe S, Lukashevich I, Kawaoka Y. Reverse genetics demonstrates that proteolytic processing of the Ebola virus glycoprotein is not essential for replication in cell culture. J. Virol. 76(1), 406–410 (2002).
  • Geisbert TW, Young HA, Jahrling PB et al. Pathogenesis of Ebola hemorrhagic fever in cynomolgus macaques: evidence that dendritic cells are early and sustained targets of infection. Am. J. Pathol. 163(6), 2347–2370 (2003).
  • Geisbert TW, Jahrling PB, Larsen T, Davis KJ, Hensley LE. Filovirus pathogenesis in nonhuman primates. In: Ebola and Marburg Viruses: Molecular and Cellular Biology. Klenk HD, Feldmann H (Eds). Horizon Bioscience, Norfolk, UK, 203–238 (2004).
  • Geisbert TW, Young HA, Jahrling PB, Davis KJ, Kagan E, Hensley LE. Mechanisms underlying coagulation abnormalities in ebola hemorrhagic fever: overexpression of tissue factor in primate monocytes/macrophages is a key event. J. Infect. Dis. 188(11), 1618–1629 (2003).
  • Schou S, Hansen AK. Marburg and Ebola virus infections in laboratory non-human primates: a literature review. Comp. Med. 50(2), 108–123 (2000).
  • Bray M, Davis K, Geisbert T, Schmaljohn C, Huggins J. A mouse model for evaluation of prophylaxis and therapy of Ebola hemorrhagic fever. J. Infect. Dis. 178(3), 651–661 (1998).
  • Connolly BM, Steele KE, Davis KJ et al. Pathogenesis of experimental Ebola virus infection in guinea-pigs. J. Infect. Dis. 179(Suppl. 1), S203–S217 (1999).
  • Formenty P, Hatz C, Le Guenno B, Stoll A, Rogenmoser P, Widmer A. Human infection due to Ebola virus, subtype Cote d’Ivoire: clinical and biologic presentation. J. Infect. Dis. 179(Suppl. 1), S48–S53 (1999).
  • Ksiazek TG, Rollin PE, Williams AJ et al. Clinical virology of Ebola hemorrhagic fever (EHF): virus, virus antigen, and IgG and IgM antibody findings among EHF patients in Kikwit, Democratic Republic of the Congo, 1995. J. Infect. Dis. 179(Suppl. 1), S177–S187 (1999).
  • Rowe AK, Bertolli J, Khan AS et al. Clinical, virologic, and immunologic follow-up of convalescent Ebola hemorrhagic fever patients and their household contacts, Kikwit, Democratic Republic of the Congo. Commission de Lutte contre les Epidemies a Kikwit. J. Infect. Dis. 179(Suppl. 1), S28–S35 (1999).
  • Dowell SF, Mukunu R, Ksiazek TG, Khan AS, Rollin PE, Peters CJ. Transmission of Ebola hemorrhagic fever: a study of risk factors in family members, Kikwit, Democratic Republic of the Congo, 1995. Commission de Lutte contre les Epidemies a Kikwit. J. Infect. Dis. 179(Suppl. 1), S87–S91 (1999).
  • Sureau PH. Firsthand clinical observations of hemorrhagic manifestations in Ebola hemorrhagic fever in Zaire. Rev. Infect. Dis. 11(Suppl. 4), S790–S793 (1989).
  • Andrijich VB. Marburg virus disease. The diagnosis and management of suspected cases. S. Afr. Med. J. 60(19), 751–753 (1981).
  • Towner JS, Rollin PE, Bausch DG et al. Rapid diagnosis of Ebola hemorrhagic fever by reverse transcription-PCR in an outbreak setting and assessment of patient viral load as a predictor of outcome. J. Virol. 78(8), 4330–4341 (2004).
  • Geisbert TW, Pushko P, Anderson K, Smith J, Davis KJ, Jahrling PB. Evaluation in nonhuman primates of vaccines against Ebola virus. Emerg. Infect. Dis. 8(5), 503–507 (2002).
  • Geisbert TW, Hensley LE, Jahrling PB et al. Treatment of Ebola virus infection with a recombinant inhibitor of Factor VIIa/tissue factor: a study in rhesus monkeys. Lancet 362(9400), 1953–1958 (2003).
  • Feldmann H et al. Filoviridae. In: Virus Taxonomy: VIIIth Report of the International Committee on Taxonomy of Viruses. Fauquet C, Mayo MA, Maniloff J, Desselberger U, Ball LA (Eds). Elsevier/Academic Press, London, UK, 645–653 (2004).
  • Muhlberger E. Genome organization, replication, and transcription of filoviruses. In: Ebola and Marburg Viruses: Molecular and Cellular Biology. Klenk HD, Feldmann H (Eds). Horizon Bioscience, Norfolk, UK, 1–26 (2004).
  • Jasenosky LD, Kawaoka Y. Filovirus budding. Virus Res. 106(2), 181–188 (2004).
  • Neumann G, Noda T, Takada A, Jasenosky LD, Kawaoka Y. Roles of filoviral matrix- and glycoproteins in the viral life cycle. In: Ebola and Marburg Viruses: Molecular and Cellular Biology. Klenk HD, Feldmann H (Eds). Horizon Bioscience, Norfolk, UK, 137–170 (2004).
  • Kolesnikova L, Becker S. Virus maturation. In: Ebola and Marburg Viruses: Molecular and Cellular Biology. Klenk HD, Feldmann H (Eds). Horizon Bioscience, Norfolk, UK, 171–201 (2004).
  • Baize S, Leroy EM, Georges-Courbot MC et al. Defective humoral responses and extensive intravascular apoptosis are associated with fatal outcome in Ebola virus-infected patients. Nature Med. 5(4), 423–426 (1999).
  • Geisbert TW, Hensley LE, Gibb TR, Steele KE, Jaax NK, Jahrling PB. Apoptosis induced in vitro and in vivo during infection by Ebola and Marburg viruses. Lab. Invest. 80(2), 171–186 (2000).
  • Villinger F, Rollin PE, Brar SS et al. Markedly elevated levels of interferon (IFN)-gamma, IFN-alpha, interleukin (IL)-2, IL-10, and tumor necrosis factor-alpha associated with fatal Ebola virus infection. J. Infect. Dis. 179(Suppl. 1), S188–S191 (1999).
  • Stroher U, West E, Bugany H, Klenk HD, Schnittler HJ, Feldmann H. Infection and activation of monocytes by Marburg and Ebola viruses. J. Virol. 75(22), 11025–11033 (2001).
  • Baize S, Leroy EM, Georges AJ et al. Inflammatory responses in Ebola virus-infected patients. Clin. Exp. Immunol. 128(1), 163–168 (2002).
  • Hensley LE, Young HA, Jahrling PB, Geisbert TW. Pro-inflammatory response during Ebola virus infection of primate models: possible involvement of the tumor necrosis factor receptor superfamily. Immunol. Lett. 80(3), 169–179 (2002).
  • Sanchez A, Lukwiya M, Bausch D et al. Analysis of human peripheral blood samples from fatal and nonfatal cases of Ebola (Sudan) hemorrhagic fever: cellular responses, virus load, and nitric oxide levels. J. Virol. 78(19), 10370–10377 (2004).
  • Geisbert TW, Young HA, Jahrling PB et al. Pathogenesis of Ebola hemorrhagic fever in primate models: evidence that hemorrhage is not a direct effect of virus-induced cytolysis of endothelial cells. Am. J. Pathol. 163(6), 2371–2382 (2003).
  • Feldmann H, Bugany H, Mahner F, Klenk HD, Drenckhahn D, Schnittler HJ. Filovirus-induced endothelial leakage triggered by infected monocytes/macrophages. J. Virol. 70(4), 2208–2214 (1996).
  • Schnittler HJ, Feldmann H. Viral hemorrhagic fever – a vascular disease? Thromb. Haemost. 89(6), 967–972 (2003).
  • World Health Organization. Ebola haemorrhagic fever in Zaire, 1976. Bull. World Health Organ. 56(2), 271–293 (1978).
  • Geisbert TW, Jahrling PB, Hanes MA, Zack PM. Association of Ebola-related Reston virus particles and antigen with tissue lesions of monkeys imported to the United States. J. Comp. Pathol. 106(2), 137–152 (1992).
  • Jaax NK, Davis KJ, Geisbert TJ et al. Lethal experimental infection of rhesus monkeys with Ebola-Zaire (Mayinga) virus by the oral and conjunctival route of exposure. Arch. Pathol. Lab. Med. 120(2), 140–155 (1996).
  • Bray M, Hatfill S, Hensley L, Huggins JW. Haematological, biochemical and coagulation changes in mice, guinea-pigs and monkeys infected with a mouse-adapted variant of Ebola Zaire virus. J. Comp. Pathol. 125(4), 243–253 (2001).
  • Fisher-Hoch SP, Platt GS, Neild GH et al. Pathophysiology of shock and hemorrhage in a fulminating viral infection (Ebola). J. Infect. Dis. 152(5), 887–894 (1985).
  • Murphy FA. Pathology of Ebola Virus Infection. Elsevier/North-Holland Biomedical Press, NY, USA (1978).
  • Isaacson M, Sureau P, Courteille G, Pattyn SR. Clinical aspects of Ebola virus disease at the Ngaliema Hospital, Kinshasa, Zaire, 1976. Elsevier/North-Holland Biomedical Press, NY, USA (1978).
  • Feldmann H, Nichol ST, Klenk HD, Peters CJ, Sanchez A. Characterization of filoviruses based on differences in structure and antigenicity of the virion glycoprotein. Virology 199(2), 469–473 (1994).
  • Wool-Lewis RJ, Bates P. Endoproteolytic processing of the ebola virus envelope glycoprotein: cleavage is not required for function. J. Virol. 73(2), 1419–1426 (1999).
  • Feldmann H, Volchkov VE, Volchkova VA, Klenk HD. The glycoproteins of Marburg and Ebola virus and their potential roles in pathogenesis. Arch. Virol. Suppl. 15, 159–169 (1999).
  • Sanchez A, Yang ZY, Xu L, Nabel GJ, Crews T, Peters CJ. Biochemical analysis of the secreted and virion glycoproteins of Ebola virus. J. Virol. 72(8), 6442–6447 (1998).
  • Weissenhorn W, Carfi A, Lee KH, Skehel JJ, Wiley DC. Crystal structure of the Ebola virus membrane fusion subunit, GP2, from the envelope glycoprotein ectodomain. Mol. Cell 2(5), 605–616 (1998).
  • Volchkov VE, Becker S, Volchkova VA et al. GP mRNA of Ebola virus is edited by the Ebola virus polymerase and by T7 and vaccinia virus polymerases. Virology 214(2), 421–430 (1995).
  • Yonezawa A, Cavrois M, Greene WC. Studies of ebola virus glycoprotein-mediated entry and fusion by using pseudotyped human immunodeficiency virus Type 1 virions: involvement of cytoskeletal proteins and enhancement by tumor necrosis factor alpha. J. Virol. 79(2), 918–926 (2005).
  • Adam B, Lins L, Stroobant V, Thomas A, Brasseur R. Distribution of hydrophobic residues is crucial for the fusogenic properties of the Ebola virus GP2 fusion peptide. J. Virol. 78(4), 2131–2136 (2004).
  • Gomara MJ, Mora P, Mingarro I, Nieva JL. Roles of a conserved proline in the internal fusion peptide of Ebola glycoprotein. FEBS Lett. 569(1–3), 261–266 (2004).
  • Delos SE, White JM. Critical role for the cysteines flanking the internal fusion peptide of avian sarcoma/leukosis virus envelope glycoprotein. J. Virol. 74(20), 9738–9741 (2000).
  • Dutch RE, Jardetzky TS, Lamb RA. Virus membrane fusion proteins: biological machines that undergo a metamorphosis. Biosci. Rep. 20(6), 597–612 (2000).
  • Malashkevich VN, Schneider BJ, McNally ML, Milhollen MA, Pang JX, Kim PS. Core structure of the envelope glycoprotein GP2 from Ebola virus at 1.9-A resolution. Proc. Natl Acad. Sci. USA 96(6), 2662–2667 (1999).
  • Ito H, Watanabe S, Sanchez A, Whitt MA, Kawaoka Y. Mutational analysis of the putative fusion domain of Ebola virus glycoprotein. J. Virol. 73(10), 8907–8912 (1999).
  • Weissenhorn W, Dessen A, Calder LJ, Harrison SC, Skehel JJ, Wiley DC. Structural basis for membrane fusion by enveloped viruses. Mol. Membr. Biol. 16(1), 3–9 (1999).
  • Hardy H, Skolnik PR. Enfuvirtide, a new fusion inhibitor for therapy of human immunodeficiency virus infection. Pharmacotherapy 24(2), 198–211 (2004).
  • Watanabe S, Takada A, Watanabe T, Ito H, Kida H, Kawaoka Y. Functional importance of the coiled-coil of the Ebola virus glycoprotein. J. Virol. 74(21), 10194–10201 (2000).
  • Weissenhorn W, Calder LJ, Wharton SA, Skehel JJ, Wiley DC. The central structural feature of the membrane fusion protein subunit from the Ebola virus glycoprotein is a long triple-stranded coiled coil. Proc. Natl Acad. Sci. USA 95(11), 6032–6036 (1998).
  • Chandran K, Sullivan NJ, Felbor U, Whelan SP, Cunningham JM. Endosomal proteolysis of the Ebola virus glycoprotein is necessary for infection. Science 308(5728), 1643–1645 (2005).
  • Kawaoka Y. How Ebola virus infects cells. N. Engl. J. Med. 352(25), 2645–2646 (2005).
  • Feldmann H, Klenk HD, Sanchez A. Molecular biology and evolution of filoviruses. Arch. Virol. Suppl. 7, 81–100 (1993).
  • Muhlberger E, Weik M, Volchkov VE, Klenk HD, Becker S. Comparison of the transcription and replication strategies of marburg virus and Ebola virus by using artificial replication systems. J. Virol. 73(3), 2333–2342 (1999).
  • Hartlieb B, Modrof J, Muhlberger E, Klenk HD, Becker S. Oligomerization of Ebola virus VP30 is essential for viral transcription and can be inhibited by a synthetic peptide. J. Biol. Chem. 278(43), 41830–41836 (2003).
  • Severson WE, Schmaljohn CS, Javadian A, Jonsson CB. Ribavirin causes error catastrophe during Hantaan virus replication. J. Virol. 77(1), 481–488 (2003).
  • Huggins JW. Prospects for treatment of viral hemorrhagic fevers with ribavirin, a broad spectrum antiviral drug. Rev. Infect. Dis. 11(Suppl. 4), S750–S761 (1989).
  • Ignat’ev GM, Strel'tsova MA, Agafonov AP, Kashentseva EA, Prozorovskii NS. Experimental study of possible treatment of Marburg hemorrhagic fever with desferal, ribavirin, and homologous interferon. Vopr. Virusol. 41(5), 206–209 (1996).
  • Fowler T, Bamberg S, Moller P et al. Inhibition of Marburg virus protein expression and viral release by RNA interference. J. Gen. Virol. 86(Pt 4), 1181–1188 (2005).
  • Ge Q, Filip L, Bai A, Nguyen T, Eisen HN, Chen J. Inhibition of influenza virus production in virus-infected mice by RNA interference. Proc. Natl Acad. Sci. USA 101(23), 8676–8681 (2004).
  • Irie T, Licata JM, McGettigan JP, Schnell MJ, Harty RN. Budding of PPxY-containing rhabdoviruses is not dependent on host proteins TGS101 and VPS4A. J. Virol. 78(6), 2657–2665 (2004).
  • Licata JM, Johnson RF, Han Z, Harty RN. Contribution of ebola virus glycoprotein, nucleoprotein, and VP24 to budding of VP40 virus-like particles. J. Virol. 78(14), 7344–7351 (2004).
  • Timmins J, Schoehn G, Ricard-Blum S et al. Ebola virus matrix protein VP40 interaction with human cellular factors Tsg101 and Nedd4. J. Mol. Biol. 326(2), 493–502 (2003).
  • Yasuda J, Nakao M, Kawaoka Y, Shida H. Nedd4 regulates egress of Ebola virus-like particles from host cells. J. Virol. 77(18), 9987–9992 (2003).
  • Licata JM, Simpson-Holley M, Wright NT, Han Z, Paragas J, Harty RN. Overlapping motifs (PTAP and PPEY) within the Ebola virus VP40 protein function independently as late budding domains: involvement of host proteins TSG101 and VPS-4. J. Virol. 77(3), 1812–1819 (2003).
  • Harty RN, Brown ME, Wang G, Huibregtse J, Hayes FP. A PPxY motif within the VP40 protein of Ebola virus interacts physically and functionally with a ubiquitin ligase: implications for filovirus budding. Proc. Natl Acad. Sci. USA 97(25), 13871–13876 (2000).
  • Neumann G, Ebihara H, Takada A et al. Ebola virus VP40 late domains are not essential for viral replication in cell culture. J. Virol. 79(16), 10300–10307 (2005).
  • Basler CF, Wang X, Muhlberger E et al. The Ebola virus VP35 protein functions as a Type I IFN antagonist. Proc. Natl Acad. Sci. USA 97(22), 12289–12294 (2000).
  • Basler CF, Mikulasova A, Martinez-Sobrido L et al. The Ebola virus VP35 protein inhibits activation of interferon regulatory factor 3. J. Virol. 77(14), 7945–7956 (2003).
  • Basler CF, Palese P. Modulation of innate immunity by filoviruses. In: Ebola and Marburg Viruses: Molecular and Cellular Biology. Klenk HD, Feldmann H (Eds). Horizon Bioscience, Norfolk, UK, 305–349 (2004).
  • Bray M. The role of the Type I interferon response in the resistance of mice to filovirus infection. J. Gen. Virol. 82(Pt 6), 1365–1373 (2001).
  • Takada A, Robison C, Goto H et al. A system for functional analysis of Ebola virus glycoprotein. Proc. Natl Acad. Sci. USA 94(26), 14764–14769 (1997).
  • Wool-Lewis RJ, Bates P. Characterization of Ebola virus entry by using pseudotyped viruses: identification of receptor-deficient cell lines. J. Virol. 72(4), 3155–3160 (1998).
  • Parren PW, Geisbert TW, Maruyama T, Jahrling PB, Burton DR et al. Pre- and postexposure prophylaxis of Ebola virus infection in an animal model bypassive transfer of a neutralizing human antibody. J. Virol. 76(12), 6408–6412 (2002).
  • Tikunova NV, Kolokol’tsov AA, Chepurnov AA. Recombinant monoclonal human antibodies against Ebola virus. Dokl. Biochem. Biophys. 378, 195–197 (2001).
  • Wilson JA, Hevey M, Bakken R et al. Epitopes involved in antibody-mediated protection from Ebola virus. Science 287(5458), 1664–1666 (2000).
  • Maruyama T, Rodriguez LL, Jahrling PB et al. Ebola virus can be effectively neutralized by antibody produced in natural human infection. J. Virol. 73(7), 6024–6030 (1999).
  • Jahrling PB, Geisbert TW, Geisbert JB et al. Evaluation of immune globulin and recombinant interferon-alpha2b for treatment of experimental Ebola virus infections. J. Infect. Dis. 179(Suppl. 1), S224–S234 (1999).
  • Markin VA, Mikhailov VV, Krasnianskii VP, Borisevich IV, Firsova IV. Developing principles for emergency prevention and treatment of Ebola fever. Vopr. Virusol. 42(1), 31–34 (1997).
  • Borisevich IV, Mikhailov VV, Krasnianskii VP et al. Development and study of the properties of immunoglobulin against Ebola fever. Vopr. Virusol. 40(6), 270–273 (1995).
  • Madani N, Perdigoto AL, Srinivasan K et al. Localized changes in the gp120 envelope glycoprotein confer resistance to human immunodeficiency virus entry inhibitors BMS-806 and 155. J. Virol. 78(7), 3742–3752 (2004).
  • Chan SY, Speck RF, Ma MC, Goldsmith MA. Distinct mechanisms of entry by envelope glycoproteins of Marburg and Ebola (Zaire) viruses. J. Virol. 74(10), 4933–4937 (2000).
  • Kolokol’tsov AA, Davidovich IA, Strel'tsova MA, Nesterov AE, Agafonova OA, Agafonov AP. The use of interferon for emergency prophylaxis of marburg hemorrhagic fever in monkeys. Bull. Exp. Biol. Med. 132(1), 686–688 (2001).
  • Bray M, Paragas J. Experimental therapy of filovirus infections. Antiviral Res. 54(1), 1–17 (2002).
  • Schroder M, Bowie AG. TLR3 in antiviral immunity: key player or bystander? Trends Immunol. 26(9), 462–468 (2005).
  • Ignatyev G, Steinkasserer A, Streltsova M, Atrasheuskaya A, Agafonov A, Lubitz W. Experimental study on the possibility of treatment of some hemorrhagic fevers. J. Biotechnol. 83(1–2), 67–76 (2000).
  • Riedemann NC, Neff TA, Guo RF et al. Protective effects of IL-6 blockade in sepsis are linked to reduced C5a receptor expression. J. Immunol. 170(1), 503–507 (2003).
  • Pallua N, Low JF, von Heimburg D. Pathogenic role of interleukin-6 in the development of sepsis. Part II: significance of anti-interleukin-6 and antisoluble interleukin-6 receptor-alpha antibodies in a standardized murine contact burn model. Crit. Care Med. 31(5), 1495–1501 (2003).
  • Miura Y, Misawa N, Maeda N et al. Critical contribution of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to apoptosis of human CD4+ T-cells in HIV-1-infected hu-PBL-NOD-SCID mice. J. Exp. Med. 193(5), 651–660 (2001).
  • Hotchkiss RS, Chang KC, Swanson PE et al. Caspase inhibitors improve survival in sepsis: a critical role of the lymphocyte. Nat. Immunol. 1(6), 496–501 (2000).
  • Gear JS, Cassel GA, Gear AJ et al. Outbreake of Marburg virus disease in Johannesburg. Br. Med. J. 4(5995), 489–493 (1975).
  • Bernard GR, Vincent JL, Laterre PF et al. Efficacy and safety of recombinant human activated protein C for severe sepsis. N. Engl. J. Med. 344(10), 699–709 (2001).

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.