EV71 infection induces neurodegeneration via activating TLR7 signaling and IL-6 production

Autoři: Zhen Luo aff001;  Rui Su aff002;  Wenbiao Wang aff001;  Yicong Liang aff001;  Xiaofeng Zeng aff003;  Muhammad Adnan Shereen aff002;  Nadia Bashir aff002;  Qi Zhang aff002;  Ling Zhao aff004;  Kailang Wu aff002;  Yingle Liu aff001;  Jianguo Wu aff001
Působiště autorů: Guangdong Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China aff001;  State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China aff002;  School of Forensic Medicine, Kunming Medical University, Kunming, China aff003;  State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China aff004
Vyšlo v časopise: EV71 infection induces neurodegeneration via activating TLR7 signaling and IL-6 production. PLoS Pathog 15(11): e32767. doi:10.1371/journal.ppat.1008142
Kategorie: Research Article
doi: https://doi.org/10.1371/journal.ppat.1008142


As a neurotropic virus, human Enterovirus 71 (EV71) infection causes hand-foot-and-mouth disease (HFMD) and may develop severe neurological disorders in infants. Toll-like receptor 7 (TLR7) acts as an innate immune receptor and is also a death receptor in the central nervous system (CNS). However, the mechanisms underlying the regulation of TLR7-mediated brain pathogenesis upon EV71 infection remain largely elusive. Here we reveal a novel mechanism by which EV71 infects astrocytes in the brain and induces neural pathogenesis via TLR7 and interleukin-6 (IL-6) in C57BL/6 mice and in human astroglioma U251 cells. Upon EV71 infection, wild-type (WT) mice displayed more significant body weight loss, higher clinical scores, and lower survival rates as compared with TLR7-/- mice. In the cerebral cortex of EV71-infected mice, neurofilament integrity was disrupted, and inflammatory cell infiltration and neurodegeneration were induced in WT mice, whereas these were largely absent in TLR7-/- mice. Similarly, IL-6 production, Caspase-3 cleavage, and cell apoptosis were significantly higher in EV71-infected WT mice as compared with TLR7-/- mice. Moreover, EV71 preferentially infected and induced IL-6 in astrocytes of mice brain. In U251 cells, EV71-induced IL-6 production and cell apoptosis were suppressed by shRNA-mediated knockdown of TLR7 (shTLR7). Moreover, in the cerebral cortex of EV71-infected mice, the blockade of IL-6 with anti-IL-6 antibody (IL-6-Ab) restored the body weight loss, attenuated clinical scores, improved survival rates, reduced the disruption of neurofilament integrity, decreased cell apoptotic induction, and lowered levels of Caspase-3 cleavage. Similarly, in EV71-infected U251 cells, IL-6-Ab blocked EV71-induced IL-6 production and cell apoptosis in response to viral infection. Collectively, it’s exhibited TLR7 upregulation, IL-6 induction and astrocytic cell apoptosis in EV71-infected human brain. Taken together, we propose that EV71 infects astrocytes of the cerebral cortex in mice and human and triggers TLR7 signaling and IL-6 release, subsequently inducing neural pathogenesis in the brain.

Klíčová slova:

Apoptosis – Astrocytes – Cerebellum – Cerebral cortex – Immunohistochemistry techniques – Mouse models – Neurons – Toll-like receptors


1. Huang PN, Shih SR (2014) Update on enterovirus 71 infection. Curr Opin Virol 5: 98–104. doi: 10.1016/j.coviro.2014.03.007 24727707

2. Hu Y, Jiang L, Peng HL (2015) Clinical Analysis of 134 Children with Nervous System Damage Caused by Enterovirus 71 Infection. Pediatr Infect Dis J 34: 718–723. doi: 10.1097/INF.0000000000000711 25860536

3. Xu Y, Ma S, Zhu L, Huang Z, Chen L, et al. (2017) Clinically isolated enterovirus A71 subgenogroup C4 strain with lethal pathogenicity in 14-day-old mice and the application as an EV-A71 mouse infection model. Antiviral Res 137: 67–75. doi: 10.1016/j.antiviral.2016.11.008 27864074

4. Zhu J, Chen N, Zhou S, Zheng K, Sun L, et al. (2018) Severity of enterovirus A71 infection in a human SCARB2 knock-in mouse model is dependent on infectious strain and route. Emerg Microbes Infect 7: 205. doi: 10.1038/s41426-018-0201-3 30518755

5. Solomon T, Lewthwaite P, Perera D, Cardosa MJ, McMinn P, et al. (2010) Virology, epidemiology, pathogenesis, and control of enterovirus 71. Lancet Infect Dis 10: 778–790. doi: 10.1016/S1473-3099(10)70194-8 20961813

6. Wang MG, Sun HM, Liu XM, Deng XQ (2017) Clinical analysis of 59 children with hand foot and mouth diseases due to enterovirus EV71 and concomitant viral encephalitis. Eur Rev Med Pharmacol Sci 21: 43–49.

7. Zhang Y, Zhu Z, Yang W, Ren J, Tan X, et al. (2010) An emerging recombinant human enterovirus 71 responsible for the 2008 outbreak of hand foot and mouth disease in Fuyang city of China. Virol J 7: 94. doi: 10.1186/1743-422X-7-94 20459851

8. Xing W, Liao Q, Viboud C, Zhang J, Sun J, et al. (2014) Hand, foot, and mouth disease in China, 2008–12: an epidemiological study. Lancet Infect Dis 14: 308–318. doi: 10.1016/S1473-3099(13)70342-6 24485991

9. Teoh HL, Mohammad SS, Britton PN, Kandula T, Lorentzos MS, et al. (2016) Clinical Characteristics and Functional Motor Outcomes of Enterovirus 71 Neurological Disease in Children. JAMA Neurol 73: 300–307. doi: 10.1001/jamaneurol.2015.4388 26785318

10. Hornung V, Guenthner-Biller M, Bourquin C, Ablasser A, Schlee M, et al. (2005) Sequence-specific potent induction of IFN-alpha by short interfering RNA in plasmacytoid dendritic cells through TLR7. Nat Med 11: 263–270. doi: 10.1038/nm1191 15723075

11. Lehmann SM, Kruger C, Park B, Derkow K, Rosenberger K, et al. (2012) An unconventional role for miRNA: let-7 activates Toll-like receptor 7 and causes neurodegeneration. Nat Neurosci 15: 827–835. doi: 10.1038/nn.3113 22610069

12. Yelamanchili SV, Lamberty BG, Rennard DA, Morsey BM, Hochfelder CG, et al. (2018) Correction: MiR-21 in Extracellular Vesicles Leads to Neurotoxicity via TLR7 Signaling in SIV Neurological Disease. PLoS Pathog 14: e1007068. doi: 10.1371/journal.ppat.1007068 29758080

13. Gu L, Zhou J, Tan J, Su L, Wei Q, et al. (2016) TLR7 rs2897827 Polymorphism Affects TLR7 Gene mRNA Expression and Serum Apolipoprotein A1 Level of Ischemic Stroke Patients in a Chinese Han Population. J Mol Neurosci 59: 397–403. doi: 10.1007/s12031-016-0773-0 27427388

14. Hu G, Liao K, Niu F, Yang L, Dallon BW, et al. (2018) Astrocyte EV-Induced lincRNA-Cox2 Regulates Microglial Phagocytosis: Implications for Morphine-Mediated Neurodegeneration. Mol Ther Nucleic Acids 13: 450–463. doi: 10.1016/j.omtn.2018.09.019 30388619

15. Chang CY, Li JR, Ou YC, Lin SY, Wang YY, et al. (2017) Interplay of inflammatory gene expression in pericytes following Japanese encephalitis virus infection. Brain Behav Immun 66: 230–243. doi: 10.1016/j.bbi.2017.07.003 28690034

16. Varani S, Gelsomino F, Bartoletti M, Viale P, Mastroianni A, et al. (2015) Meningitis Caused by Toscana Virus Is Associated with Strong Antiviral Response in the CNS and Altered Frequency of Blood Antigen-Presenting Cells. Viruses 7: 5831–5843. doi: 10.3390/v7112909 26569288

17. Gong X, Zhou J, Zhu W, Liu N, Li J, et al. (2012) Excessive proinflammatory cytokine and chemokine responses of human monocyte-derived macrophages to enterovirus 71 infection. BMC Infect Dis 12: 224. doi: 10.1186/1471-2334-12-224 22994237

18. Chi C, Sun Q, Wang S, Zhang Z, Li X, et al. (2013) Robust antiviral responses to enterovirus 71 infection in human intestinal epithelial cells. Virus Res 176: 53–60. doi: 10.1016/j.virusres.2013.05.002 23685430

19. Luo Z, Ge M, Chen J, Geng Q, Tian M, et al. (2017) HRS plays an important role for TLR7 signaling to orchestrate inflammation and innate immunity upon EV71 infection. PLOS Pathogens 13: e1006585. doi: 10.1371/journal.ppat.1006585 28854257

20. Zhu L, Li W, Qi G, Liu N, Sheng L, et al. (2017) The immune mechanism of intestinal tract Toll-like receptor in mediating EV71 virus type severe hand-foot-and-mouth disease and the MAPK pathway. Exp Ther Med 13: 2263–2266. doi: 10.3892/etm.2017.4245 28565836

21. Mukherjee S, Akbar I, Kumari B, Vrati S, Basu A, et al. (2018) Japanese Encephalitis Virus-induced let-7a/b interacted with the NOTCH-TLR7 pathway in microglia and facilitated neuronal death via caspase activation. J Neurochem.

22. de Sousa JR, Azevedo RSS, Martins Filho AJ, Araujo MTF, Moutinho ERC, et al. (2018) Correlation between Apoptosis and in Situ Immune Response in Fatal Cases of Microcephaly Caused by Zika Virus. Am J Pathol 188: 2644–2652. doi: 10.1016/j.ajpath.2018.07.009 30121258

23. Yuan A, Rao MV, Veeranna, Nixon RA (2017) Neurofilaments and Neurofilament Proteins in Health and Disease. Cold Spring Harb Perspect Biol 9.

24. Berger M, Ponnusamy V, Greene N, Cooter M, Nadler JW, et al. (2017) The Effect of Propofol vs. Isoflurane Anesthesia on Postoperative Changes in Cerebrospinal Fluid Cytokine Levels: Results from a Randomized Trial. Front Immunol 8: 1528. doi: 10.3389/fimmu.2017.01528 29181002

25. Baar MP, Brandt RMC, Putavet DA, Klein JDD, Derks KWJ, et al. (2017) Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging. Cell 169: 132–147 e116. doi: 10.1016/j.cell.2017.02.031 28340339

26. Gurel B, Cansev M, Sevinc C, Kelestemur S, Ocalan B, et al. (2018) Early Stage Alterations in CA1 Extracellular Region Proteins Indicate Dysregulation of IL6 and Iron Homeostasis in the 5XFAD Alzheimer's Disease Mouse Model. J Alzheimers Dis 61: 1399–1410. doi: 10.3233/JAD-170329 29376847

27. Zhan X, Desiderio DM (2010) The use of variations in proteomes to predict, prevent, and personalize treatment for clinically nonfunctional pituitary adenomas. EPMA J 1: 439–459. doi: 10.1007/s13167-010-0028-z 23199087

28. Hung YF, Chen CY, Li WC, Wang TF, Hsueh YP (2018) Tlr7 deletion alters expression profiles of genes related to neural function and regulates mouse behaviors and contextual memory. Brain Behav Immun 72: 101–113. doi: 10.1016/j.bbi.2018.06.006 29885943

29. Feng M, Guo S, Fan S, Zeng X, Zhang Y, et al. (2016) The Preferential Infection of Astrocytes by Enterovirus 71 Plays a Key Role in the Viral Neurogenic Pathogenesis. Front Cell Infect Microbiol 6: 192. doi: 10.3389/fcimb.2016.00192 28066727

30. Choi SS, Lee HJ, Lim I, Satoh J, Kim SU (2014) Human astrocytes: secretome profiles of cytokines and chemokines. PLoS One 9: e92325. doi: 10.1371/journal.pone.0092325 24691121

31. Zhang Z, Ohto U, Shibata T, Krayukhina E, Taoka M, et al. (2016) Structural Analysis Reveals that Toll-like Receptor 7 Is a Dual Receptor for Guanosine and Single-Stranded RNA. Immunity 45: 737–748. doi: 10.1016/j.immuni.2016.09.011 27742543

32. Galatro TF, Holtman IR, Lerario AM, Vainchtein ID, Brouwer N, et al. (2017) Transcriptomic analysis of purified human cortical microglia reveals age-associated changes. Nat Neurosci 20: 1162–1171. doi: 10.1038/nn.4597 28671693

33. Zhang CJ, Jiang M, Zhou H, Liu W, Wang C, et al. (2018) TLR-stimulated IRAKM activates caspase-8 inflammasome in microglia and promotes neuroinflammation. J Clin Invest 128: 5399–5412. doi: 10.1172/JCI121901 30372424

34. Pandey GN, Rizavi HS, Bhaumik R, Ren X (2019) Innate immunity in the postmortem brain of depressed and suicide subjects: Role of Toll-like receptors. Brain Behav Immun 75: 101–111. doi: 10.1016/j.bbi.2018.09.024 30266463

35. Caputi V, Giron MC (2018) Microbiome-Gut-Brain Axis and Toll-Like Receptors in Parkinson's Disease. Int J Mol Sci 19.

36. Shi H, Hua X, Kong D, Stein D, Hua F (2019) Role of Toll-like receptor mediated signaling in traumatic brain injury. Neuropharmacology 145: 259–267. doi: 10.1016/j.neuropharm.2018.07.022 30075158

37. Lou B, De Beuckelaer A, Boonstra E, Li D, De Geest BG, et al. (2019) Modular core-shell polymeric nanoparticles mimicking viral structures for vaccination. J Control Release 293: 48–62. doi: 10.1016/j.jconrel.2018.11.006 30428307

38. Wang G, Guo Z, Tong L, Xue F, Krafft PR, et al. (2018) TLR7 (Toll-Like Receptor 7) Facilitates Heme Scavenging Through the BTK (Bruton Tyrosine Kinase)-CRT (Calreticulin)-LRP1 (Low-Density Lipoprotein Receptor-Related Protein-1)-Hx (Hemopexin) Pathway in Murine Intracerebral Hemorrhage. Stroke 49: 3020–3029. doi: 10.1161/STROKEAHA.118.022155 30571407

39. Hsiao HB, Chou AH, Lin SI, Chen IH, Lien SP, et al. (2014) Toll-like receptor 9-mediated protection of enterovirus 71 infection in mice is due to the release of danger-associated molecular patterns. J Virol 88: 11658–11670. doi: 10.1128/JVI.00867-14 25078697

40. Zhu K, Yang J, Luo K, Yang C, Zhang N, et al. (2015) TLR3 signaling in macrophages is indispensable for the protective immunity of invariant natural killer T cells against enterovirus 71 infection. PLoS Pathog 11: e1004613. doi: 10.1371/journal.ppat.1004613 25615690

41. Wang YF, Chou CT, Lei HY, Liu CC, Wang SM, et al. (2004) A mouse-adapted enterovirus 71 strain causes neurological disease in mice after oral infection. J Virol 78: 7916–7924. doi: 10.1128/JVI.78.15.7916-7924.2004 15254164

42. Mukherjee S, Singh N, Sengupta N, Fatima M, Seth P, et al. (2017) Japanese encephalitis virus induces human neural stem/progenitor cell death by elevating GRP78, PHB and hnRNPC through ER stress. Cell Death Dis 8: e2556.

43. Khong WX, Foo DG, Trasti SL, Tan EL, Alonso S (2011) Sustained high levels of interleukin-6 contribute to the pathogenesis of enterovirus 71 in a neonate mouse model. J Virol 85: 3067–3076. doi: 10.1128/JVI.01779-10 21228224

44. Chen L, Hu L, Zhao J, Hong H, Feng F, et al. (2016) Chotosan improves Abeta1-42-induced cognitive impairment and neuroinflammatory and apoptotic responses through the inhibition of TLR-4/NF-kappaB signaling in mice. J Ethnopharmacol 191: 398–407. doi: 10.1016/j.jep.2016.03.038 26994819

45. Heneka MT, McManus RM, Latz E (2018) Inflammasome signalling in brain function and neurodegenerative disease. Nat Rev Neurosci 19: 610–621. doi: 10.1038/s41583-018-0055-7 30206330

46. Verkhratsky A, Nedergaard M (2018) Physiology of Astroglia. Physiol Rev 98: 239–389. doi: 10.1152/physrev.00042.2016 29351512

47. Colombo E, Farina C (2016) Astrocytes: Key Regulators of Neuroinflammation. Trends Immunol 37: 608–620. doi: 10.1016/j.it.2016.06.006 27443914

48. Sofroniew MV (2015) Astrocyte barriers to neurotoxic inflammation. Nat Rev Neurosci 16: 249–263. doi: 10.1038/nrn3898 25891508

49. Liddelow SA, Guttenplan KA, Clarke LE, Bennett FC, Bohlen CJ, et al. (2017) Neurotoxic reactive astrocytes are induced by activated microglia. Nature 541: 481–487. doi: 10.1038/nature21029 28099414

50. Jha MK, Jo M, Kim JH, Suk K (2018) Microglia-Astrocyte Crosstalk: An Intimate Molecular Conversation. Neuroscientist: 1073858418783959.

51. Korhonen P, Malm T, White AR (2018) 3D human brain cell models: New frontiers in disease understanding and drug discovery for neurodegenerative diseases. Neurochem Int 120: 191–199. doi: 10.1016/j.neuint.2018.08.012 30176269

52. Wang W, Li G, De W, Luo Z, Pan P, et al. (2018) Zika virus infection induces host inflammatory responses by facilitating NLRP3 inflammasome assembly and interleukin-1beta secretion. Nat Commun 9: 106. doi: 10.1038/s41467-017-02645-3 29317641

53. Potokar M, Jorgacevski J, Zorec R (2019) Astrocytes in Flavivirus Infections. Int J Mol Sci 20.

54. Luo Z, Dong X, Li Y, Zhang Q, Kim C, et al. (2014) PolyC-binding protein 1 interacts with 5'-untranslated region of enterovirus 71 RNA in membrane-associated complex to facilitate viral replication. PLoS One 9: e87491. doi: 10.1371/journal.pone.0087491 24489926

55. Ge M, Luo Z, Qiao Z, Zhou Y, Cheng X, et al. (2017) HERP Binds TBK1 To Activate Innate Immunity and Repress Virus Replication in Response to Endoplasmic Reticulum Stress. J Immunol 199: 3280–3292. doi: 10.4049/jimmunol.1700376 28954889

Hygiena a epidemiologie Infekční lékařství Laboratoř

Článek vyšel v časopise

PLOS Pathogens

2019 Číslo 11
Nejčtenější tento týden
Nejčtenější v tomto čísle

Zvyšte si kvalifikaci online z pohodlí domova

Úloha kombinovaných preparátů v léčbě arteriální hypertenze
nový kurz
Autoři: prof. MUDr. Martin Haluzík, DrSc.

Třikrát z interní medicíny
Autoři: Mgr. Jana Kubátová, Ph.D.

Pokročilá Parkinsonova nemoc − úskalí a možnosti léčby
Autoři: doc. MUDr. Marek Baláž, Ph.D.

Léčba diabetes mellitus 2. typu pomocí GLP- 1 RA

Depresivní porucha a zánětlivé procesy
Autoři: MUDr. Juraj Tkáč

Všechny kurzy
Zapomenuté heslo

Zadejte e-mailovou adresu, se kterou jste vytvářel(a) účet, budou Vám na ni zaslány informace k nastavení nového hesla.


Nemáte účet?  Registrujte se