5 MORPHOGENESIS OF ARBOVIRUSES MATURATION : (1) COMPARISON OF CHIKUNGUNYA VIRUS MATURATION IN MOSQUITO CULTURED (C6/36) AND VERO CELLS

The lack of specific treatment for chikungunya fever makes the need for anti-chikungunya virus agents more crucial. This study was conducted to evaluate 132 extracts obtained by sequential solvent extraction from 21 medicinal plants for cytopathic effect inhibitory activity using virus-infected Vero cells in two different sample introduction modes. Among the extracts, 42 extracts (31.8%) from 12 plants in the concurrent mode and three extracts (2.3%) from a plant in the non-concurrent mode displayed strong cytopathic effect inhibitory activity (cell viability ≥70%). Viral load quantification analysis unveiled that the extracts of Clinacanthus nutans (chloroform, ethyl acetate, and ethanol), Hydrocotyle sibthorpioides (ethanol), and Ocimum americanum (ethanol and methanol) hindered the release of viral progeny from the infected cells while the extracts of Ficus deltoidea (ethanol), Gynura bicolor (water), H. sibthorpioides (water), and O. americanum (chloroform and ethyl acetate) blocked the entry of virus into the cells. The extracts of Diodella sarmentosa (ethyl acetate), Diplazium esculentum (chloroform, ethyl acetate, and ethanol), and G. bicolor (ethanol) possessed virucidal effect and caused 5.41-log to 6.63-log reductions of viral load compared to the virus control. The results indicate that these medicinal plants are potential sources of anti-chikungunya virus agents that have varied modes of action.

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Assessment of in vitro prophylactic and therapeutic efficacy of chloroquine against chikungunya virus in vero cells

Journal of Medical Virology ◽

10.1002/jmv.21663 ◽

2010 ◽

Vol 82 (5) ◽

pp. 817-824 ◽

Cited By ~ 97

Author(s):

Mohsin Khan ◽

S.R. Santhosh ◽

Mugdha Tiwari ◽

P.V. Lakshmana Rao ◽

Manmohan Parida

Keyword(s):

Therapeutic Efficacy ◽

Chikungunya Virus ◽

Vero Cells

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Sendai virus maturation in actinomycin D pretreated and glutamine starved 37 RC and vero cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100082728 ◽

1978 ◽

Vol 36 (2) ◽

pp. 372-373

Author(s):

Wiktor Djaczenko ◽

Arrigo Benedetto ◽

Maria Stefania Zaniratti

Keyword(s):

Actinomycin D ◽

Sendai Virus ◽

Vero Cells ◽

Ruthenium Red ◽

The Other ◽

Surface Glycoprotein ◽

Cell Replication ◽

Virus Maturation ◽

Glass Substrates ◽

Metabolic Conditions

Actinomycin D (AMD) pretreatment (0. 5 μg/ml, 72h) causes surface glycoprotein accumulation in 37 RC and Vero cells (submitted for publication). On the other hand glutamine starvation in these cells does not inhibit the cell replication but reduces the cell adhesiveness to the plastic and glass substrates probably by depletion of glucosamine pool. In such metabolic conditions the modifications of plasma membrane flexibility could be expected. Since such a flexibility influences Sendai virus maturation we decided to study the replication of this virus in AMD pretreated and glutamine starved cells.Three groups of 37 RC and Vero cells grown in monolayers, one untreated control, one AMD pretreated and one glutamine (G) starved were infected with Sendai virus. At 3. 5h and 24 h of infection corresponding cultures were fixed by: (a) classical methods, (b) TAPO techniqe and (c) ruthenium red method.

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SELECTION OF A FAST-GROWING CHIKUNGUNYA VIRUS BY PASSAGE FROM SUCKLING MOUSE BRAIN TO VERO CELLS

Japanese Journal of Medical Science and Biology ◽

10.7883/yoken1952.25.259 ◽

1972 ◽

Vol 25 (4) ◽

pp. 259-270

Author(s):

HISAO TAKEDA

Keyword(s):

Mouse Brain ◽

Chikungunya Virus ◽

Vero Cells ◽

Suckling Mouse ◽

Fast Growing ◽

Selection Of

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Structural studies of Chikungunya virus maturation

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1713166114 ◽

2017 ◽

Vol 114 (52) ◽

pp. 13703-13707 ◽

Cited By ~ 19

Author(s):

Moh Lan Yap ◽

Thomas Klose ◽

Akane Urakami ◽

S. Saif Hasan ◽

Wataru Akahata ◽

...

Keyword(s):

Chikungunya Virus ◽

Infectious Virus ◽

Posttranslational Processing ◽

Structural Studies ◽

Virus Maturation ◽

Freedom Of Movement ◽

Ribosome Binding ◽

Immature Virus ◽

Mature Virus ◽

Resolution Structure

Cleavage of the alphavirus precursor glycoprotein p62 into the E2 and E3 glycoproteins before assembly with the nucleocapsid is the key to producing fusion-competent mature spikes on alphaviruses. Here we present a cryo-EM, 6.8-Å resolution structure of an “immature” Chikungunya virus in which the cleavage site has been mutated to inhibit proteolysis. The spikes in the immature virus have a larger radius and are less compact than in the mature virus. Furthermore, domains B on the E2 glycoproteins have less freedom of movement in the immature virus, keeping the fusion loops protected under domain B. In addition, the nucleocapsid of the immature virus is more compact than in the mature virus, protecting a conserved ribosome-binding site in the capsid protein from exposure. These differences suggest that the posttranslational processing of the spikes and nucleocapsid is necessary to produce infectious virus.

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Favipiravir Does Not Inhibit Chikungunya Virus Replication in Mosquito Cells and Aedes aegypti Mosquitoes

Microorganisms ◽

10.3390/microorganisms9050944 ◽

2021 ◽

Vol 9 (5) ◽

pp. 944

Author(s):

Sofie Jacobs ◽

Lanjiao Wang ◽

Ana Lucia Rosales Rosas ◽

Ria Van Berwaer ◽

Evelien Vanderlinden ◽

...

Keyword(s):

Antiviral Activity ◽

Aedes Aegypti ◽

Chikungunya Virus ◽

Active Form ◽

Metabolic Activation ◽

Vero Cells ◽

Mosquito Vector ◽

Chikv Infection ◽

Mosquito Cells

Favipiravir (T-705) is a broad-spectrum antiviral drug that inhibits RNA viruses after intracellular conversion into its active form, T-705 ribofuranosyl 5′-triphosphate. We previously showed that T-705 is able to significantly inhibit the replication of chikungunya virus (CHIKV), an arbovirus transmitted by Aedes mosquitoes, in mammalian cells and in mouse models. In contrast, the effect of T-705 on CHIKV infection and replication in the mosquito vector is unknown. Since the antiviral activity of T-705 has been shown to be cell line-dependent, we studied here its antiviral efficacy in Aedes-derived mosquito cells and in Aedes aegypti mosquitoes. Interestingly, T-705 was devoid of anti-CHIKV activity in mosquito cells, despite being effective against CHIKV in Vero cells. By investigating the metabolic activation profile, we showed that, unlike Vero cells, mosquito cells were not able to convert T-705 into its active form. To explore whether alternative metabolization pathways might exist in vivo, Aedes aegypti mosquitoes were infected with CHIKV and administered T-705 via an artificial blood meal. Virus titrations of whole mosquitoes showed that T-705 was not able to reduce CHIKV infection in mosquitoes. Combined, these in vitro and in vivo data indicate that T-705 lacks antiviral activity in mosquitoes due to inadequate metabolic activation in this animal species.

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Chikungunya Virus Transmission at Low Temperature by Aedes albopictus Mosquitoes

Pathogens ◽

10.3390/pathogens8030149 ◽

2019 ◽

Vol 8 (3) ◽

pp. 149 ◽

Cited By ~ 3

Author(s):

B. M. C. Randika Wimalasiri-Yapa ◽

Liesel Stassen ◽

Wenbiao Hu ◽

Laith Yakob ◽

Elizabeth A. McGraw ◽

...

Keyword(s):

South African ◽

Aedes Albopictus ◽

Post Infection ◽

Chikungunya Virus ◽

Virus Transmission ◽

Early Time ◽

Vero Cells ◽

Ambient Temperatures ◽

Time Points ◽

Central South

Aedes albopictus is an important vector of chikungunya virus (CHIKV). In Australia, Ae. albopictus is currently only known to be present on the islands of the Torres Strait but, should it invade the mainland, it is projected to spread to temperate regions. The ability of Australian Ae. albopictus to transmit CHIKV at the lower temperatures typical of temperate areas has not been assessed. Ae. albopictus mosquitoes were orally challenged with a CHIKV strain from either Asian or East/Central/South African (ECSA) genotypes (107 pfu/mL), and maintained at a constant temperature of either 18 °C or 28 °C. At 3- and 7-days post-infection (dpi), CHIKV RNA copies were quantified in mosquito bodies, and wings and legs using real time polymerase chain reaction (qRT-PCR), while the detection of virus in saliva (a proxy for transmission) was performed by amplification in cell culture followed by observation of cytopathic effect in Vero cells. Of the ≥95% of Ae. albopictus that survived to 7 dpi, all mosquitoes became infected and showed body dissemination of CHIKV at both temperatures and time points. Both the Asian and ECSA CHIKV genotypes were potentially transmissible by Australian Ae. albopictus at 28 °C within 3 days of oral challenge. In contrast, at 18 °C none of the mosquitoes showed evidence of ability to transmit either genotype of CHIKV at 3 dpi. Further, at 18 °C only Ae. albopictus infected with the ECSA genotype showed evidence of virus in saliva at 7 dpi. Overall, infection with the ECSA CHIKV genotype produced higher virus loads in mosquitoes compared to infection with the Asian CHIKV genotype. Our results suggest that lower ambient temperatures may impede transmission of some CHIKV strains by Ae. albopictus at early time points post infection.

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Chikungunya virus produced by a persistently infected mosquito cell line comprises a shorter genome and is non-infectious to mammalian cells

Journal of General Virology ◽

10.1099/jgv.0.001700 ◽

2021 ◽

Vol 102 (12) ◽

Author(s):

Athos S. de Oliveira ◽

Anna Fernanda Vasconcellos ◽

Bruno M. P. Rodrigues ◽

Leonardo A. da Silva ◽

Renato O. Resende ◽

...

Keyword(s):

Cell Line ◽

Mammalian Cells ◽

Chikungunya Virus ◽

Rna Viruses ◽

Human Fibroblasts ◽

Vero Cells ◽

Host Cells ◽

Infected Mosquito ◽

Persistently Infected ◽

Cellular Environment

Although RNA viruses have high mutation rates, host cells and organisms work as selective environments, maintaining the viability of virus populations by eliminating deleterious genotypes. In serial passages of RNA viruses in a single cell line, most of these selective bottlenecks are absent, with no virus circulation and replication in different tissues or host alternation. In this work, Aedes aegypti Aag-2 cells were accidentally infected with Chikungunya virus (CHIKV) and Mayaro virus (MAYV). After numerous passages to achieve infection persistency, the infectivity of these viruses was evaluated in Ae. albopictus C6/36 cells, African green monkey Vero cells and primary-cultured human fibroblasts. While these CHIKV and MAYV isolates were still infectious to mosquito cells, they lost their ability to infect mammalian cells. After genome sequencing, it was observed that CHIKV accumulated many nonsynonymous mutations and a significant deletion in the coding sequence of the hypervariable domain in the nsP3 gene. Since MAYV showed very low titres, it was not sequenced successfully. Persistently infected Aag-2 cells also accumulated high loads of short and recombinant CHIKV RNAs, which seemed to have been originated from virus-derived DNAs. In conclusion, the genome of this CHIKV isolate could guide mutagenesis strategies for the production of attenuated or non-infectious (to mammals) CHIKV vaccine candidates. Our results also reinforce that a paradox is expected during passages of cells persistently infected by RNA viruses: more loosening for the development of more diverse virus genotypes and more pressure for virus specialization to this constant cellular environment.

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