An Attenuated Strain of Enterovirus 71 Belonging to Genotype A Showed a Broad Spectrum of Antigenicity with Attenuated Neurovirulence in Cynomolgus Monkeys

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Poliovirus (PV) and enterovirus 71 (EV71) cause severe neurological symptoms in their infections of the central nervous system. To identify compounds with anti-PV and anti-EV71 activities that would not allow the emergence of resistant mutants, we performed drug screening by utilizing a pharmacologically active compound library targeting cellular factors with PV and EV71 pseudoviruses that encapsidated luciferase-encoding replicons. We have found that metrifudil (N-[2-methylphenyl]methyl)-adenosine) (an A2 adenosine receptor agonist), N 6 -benzyladenosine (an A1 adenosine receptor agonist) and NF449 (4,49,40,409-[carbonylbis[imino-5,1,3-benzenetriyl bis(carbonyl-imino)]] tetrakis (benzene-1,3-disulfonic acid) octasodium salt) (a Gs-a inhibitor) have anti-EV71 activity, and that GW5074 (3-(3, 5-dibromo-4-hydroxybenzylidine-5-iodo-1,3-dihydro-indol-2-one)) (a Raf-1 inhibitor) has both anti-PV and anti-EV71 activities. EV71 mutants resistant to metrifudil, N 6 -benzyladenosine and NF449 were isolated after passages in the presence of these compounds, but mutants resistant to GW5074 were not isolated for both PV and EV71. The inhibitory effect of GW5074 was not observed in Sendai virus infection and the treatment did not induce the expression of OAS1 and STAT1 mRNA. Small interfering RNA treatment against putative cellular targets of GW5074, including Raf-1, B-Raf, Pim-1, -2, and -3, HIPK2, GAK, MST2 and ATF-3, did not consistently suppress PV replication. Moreover, downregulation of Raf-1 and B-Raf did not affect the sensitivity of RD cells to the inhibitory effect of GW5074. These results suggest that GW5074 has strong and selective inhibitory effect against the replication of PV and EV71 by inhibiting conserved targets in the infection independently of the interferon response.

Section: Characterization Of Anti-enterovirus Compoundsmentioning

confidence: 99%

Characterization of pharmacologically active compounds that inhibit poliovirus and enterovirus 71 infectivity

Arita

Wakita

Shimizu

2008

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Section: Introductionmentioning

confidence: 99%

“…However, there is no effective therapeutic means for vaccine-associated paralytic poliomyelitis caused by virulent revertants of vaccine strains, which occurred at a rate of one case per 520 000 vaccinations with the first dose of the live-attenuated vaccine (Nkowane et al, 1987). For EV71, various vaccine candidates and therapeutic means are being developed, but no vaccine has been established (Arita et al, 2005a(Arita et al, , 2007Chen et al, 2006;Chiu et al, 2006;Liu et al, 2005Liu et al, , 2007 Shih et al, 2004;Tan & Cardosa, 2007;Tung et al, 2007;Wu et al, 2007; Yu et al, 2000).To date, several anti-enterovirus compounds that target cellular factors and inhibit various stages of virus replication have been identified. Brefeldin A blocks membrane traffic between the cis-and trans-Golgi compartments by targeting a cellular guanine nucleotide- exchange factor, GBF1, and inhibits the replication of PV, but not encephalomyocarditis virus (EMCV) (Belov et al, 2008;Cuconati et al, 1998;Irurzun et al, 1992;Maynell et al, 1992).…”

mentioning

confidence: 99%

Cellular kinase inhibitors that suppress enterovirus replication have a conserved target in viral protein 3A similar to that of enviroxime

Arita

Wakita

Shimizu

2009

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Previously, we identified a cellular kinase inhibitor, GW5074, that inhibits poliovirus (PV) and enterovirus 71 replication strongly, although its target has remained unknown. To identify the target of GW5074, we searched for cellular kinase inhibitors that have anti-enterovirus activity similar or related to that of GW5074. With this aim, we performed screenings to identify cellular kinase inhibitors that could inhibit PV replication cooperatively with GW5074 or synthetically in the absence of GW5074. We identified MEK1/2 inhibitors (SL327 and U0126), an EGFR inhibitor (AG1478) and a phosphatidylinositol 3-kinase inhibitor (wortmannin) as compounds with a cooperative inhibitory effect with GW5074, and an Akt1/2 inhibitor (Akt inhibitor VIII) as a compound with a synthetic inhibitory effect with MEK1/2 inhibitors and AG1478. Individual treatment with the identified kinase inhibitors did not affect PV replication significantly, but combined treatment with MEK1/2 inhibitor, AG1478 and Akt1/2 inhibitor suppressed the replication synthetically. The effect of AG1478 in this synthetic inhibition was compensated by other receptor tyrosine kinase inhibitors (IGF-1R inhibitor II and Flt3 inhibitor II). We isolated mutants resistant to Flt3 inhibitor II and GW5074 and found that these mutants had crossresistance to each treatment. These mutants had a common mutation in viral protein 3A that results in an amino acid change at position 70 (Ala to Thr), a mutation that was previously identified in mutants resistant to a potent anti-enterovirus compound, enviroxime. These results suggest that cellular kinase inhibitors and enviroxime have a conserved target in viral protein 3A to suppress enterovirus replication. INTRODUCTIONThe genus Enterovirus consists of at least ten species of non-enveloped viruses with a single-stranded, positivesense genomic RNA that belong to the family Picornaviridae. Enterovirus infection is mostly asymptomatic, but sometimes causes severe neurological symptoms exemplified by poliomyelitis. In infection by poliovirus (PV), which is the causative agent of poliomyelitis and belongs to the species Human enterovirus C, motor neurons are the major target for neurovirulence (Bodian, 1949). Enterovirus 71 (EV71), another neurotropic enterovirus belonging to the species Human enterovirus A, is a causative agent of hand, foot and mouth disease and herpangina, but sometimes causes severe neurological diseases, such as brainstem encephalitis and poliomyelitis-like paralysis (Chumakov et al., 1979;McMinn, 2002;Wang et al., 2003). EV71 causes fatal pulmonary oedema and pulmonary haemorrhage in young children by destruction of the vasomotor and respiratory centres in the brainstem Ho et al., 1999;Huang et al., 1999;Komatsu et al., 1999;Lum et al., 1998;Wang et al., 1999). For PV, live-attenuated and inactivated vaccines have been established and are currently being used for global eradication of poliomyelitis (Sabin, 1965;Salk et al., 1954). However, there is no effective therapeutic means for vaccine-associated...

“…It induced broadly neutralizing responses in immunized monkeys, but was neurotropic when inoculated intravenously and its further development was halted [136]. Development of inactivated vaccines was more successful: five such vaccines developed by different organizations entered clinical trials and three of them have already completed phase III, showing 80.4-97.4 % efficacy against EV-A71-induced HFMD in humans [137].…”

Section: Neutralization Of Picornaviruses Neutralization Of Ev-a71 Anmentioning

confidence: 99%

Human picornaviruses associated with neurological diseases and their neutralization by antibodies

Anastasina

Domanska

Palm

et al. 2017

Picornaviruses are the most commonly encountered infectious agents in mankind. They typically cause mild infections of the gastrointestinal or respiratory tract, but sometimes also invade the central nervous system. There, they can cause severe diseases with long-term sequelae and even be lethal. The most infamous picornavirus is poliovirus, for which significant epidemics of poliomyelitis were reported from the end of the nineteenth century. A successful vaccination campaign has brought poliovirus close to eradication, but neurological diseases caused by other picornaviruses have increasingly been reported since the late 1990s. In this review we focus on enterovirus 71, coxsackievirus A16, enterovirus 68 and human parechovirus 3, which have recently drawn attention because of their links to severe neurological diseases. We discuss the clinical relevance of these viruses and the primary role of humoral immunity in controlling them, and summarize current knowledge on the neutralization of such viruses by antibodies.