A Senescence-Like Cellular Response Inhibits Bovine Ephemeral Fever Virus Proliferation

During industrial-scale production of viruses for vaccine manufacturing, anti-viral response of host cells can dampen maximal viral antigen yield. In addition to interferon responses, many other cellular responses, such as the AMPK signaling pathway or senescence-like response may inhibit or slow down virus amplification in the cell culture system. In this study, we first performed a Gene Set Enrichment Analysis of the whole-genome mRNA transcriptome and found a senescence-like cellular response in BHK-21 cells when infected with bovine ephemeral fever virus (BEFV). To demonstrate that this senescence-like state may reduce virus growth, BHK-21 subclones showing varying degrees of a senescence-like state were infected with BEFV. The results showed that the BHK-21 subclones showing high senescence staining could inhibit BEFV replication while low senescence-staining subclones are permissive to virus replication. Using a different approach, a senescence-like state was induced in BHK-21 using a small molecule, camptothecin (CPT), and BEFV susceptibility were examined. The results showed that CPT-treated BHK-21 is more resistant to virus infection. Overall, these results indicate that a senescence-like response may be at play in BHK-21 upon virus infection. Furthermore, cell clone selection and modulating treatments using small molecules may be tools in countering anti-viral responses.

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A senescence-like cellular response inhibits bovine ephemeral fever virus proliferation

10.1101/2021.01.28.428738 ◽

2021 ◽

Author(s):

Yu-Jing Zeng ◽

Min-Kung Hsu ◽

Chiao-An Tsai ◽

Chun-Yen Chu ◽

Hsing-Chieh Wu ◽

...

Keyword(s):

Virus Infection ◽

Cellular Response ◽

Cell Clone ◽

Fever Virus ◽

Gene Set Enrichment Analysis ◽

Host Cells ◽

Scale Production ◽

Bovine Ephemeral Fever Virus ◽

Virus Growth ◽

Bovine Ephemeral Fever

AbstractDuring industrial scale production of virus for vaccine manufacturing, antiviral response of host cells can dampen maximal viral antigen yield. In addition to interferon responses, many other cellular responses such as the AMPK signaling pathway or senescence-like response may inhibit or slow down virus amplification in the cell culture system. In this study, we first performed a Gene Set Enrichment Analysis of the whole-genome mRNA transcriptome and found a senescence-like cellular response in BHK-21 cells when infected with bovine ephemeral fever virus (BEFV). To demonstrate that this senescence-like state may reduce virus growth, BHK-21 subclones showing varying degrees of senescence-like state were infected with BEFV. Results showed the BHK-21 subclones showing high senescence staining could inhibit BEFV replication while low senescence-staining subclones are permissive to virus replication. Using a different approach, a senescence-like state was induced in BHK-21 using a small molecule, camptothecin (CPT), and BEFV susceptibility was examined. Results showed that indeed CPT-treated BHK-21 is more resistant to virus infection. Overall, these results indicate that a senescence-like response may be at play in BHK-21 upon virus infection. Furthermore, cell clone selection and modulating treatments using small molecules may be tools in countering anti-viral responses.

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Bovine ephemeral fever virus triggers autophagy enhancing virus replication via upregulation of the Src/JNK/AP1 and PI3K/Akt/NF-κB pathways and suppression of the PI3K/Akt/mTOR pathway

Veterinary Research ◽

10.1186/s13567-019-0697-0 ◽

2019 ◽

Vol 50 (1) ◽

Cited By ~ 3

Author(s):

Ching-Yuan Cheng ◽

Hsu-Hung Tseng ◽

Hung-Chuan Chiu ◽

Ching-Dong Chang ◽

Brent L. Nielsen ◽

...

Keyword(s):

Virus Replication ◽

Cellular Response ◽

Virus Production ◽

Mtor Pathway ◽

Fever Virus ◽

Bovine Ephemeral Fever Virus ◽

Virus Binding ◽

Bovine Ephemeral Fever ◽

Mtorc1 Pathway ◽

The Impact

Abstract Autophagy plays an important role in cellular response to pathogens. However, the impact of the autophagy machinery on bovine ephemeral fever virus (BEFV) infection is not yet determined. A recent study in our laboratory demonstrated that BEFV triggers simultaneously the PI3K/Akt/NF-κB and Src/JNK-AP1 pathways in the stage of virus binding to enhance virus entry. In this work, we report that BEFV induces autophagy via upregulation of the PI3K/Akt/NF-κB and Src/JNK/AP1 pathways in the early to middle stages of infection and suppresses the PI3K/Akt/mTOR pathway at the late stage of infection. To activate NF-κB, BEFV promotes degradation of IκBα and activates Akt to stimulate NF-κB translocation into the nucleus. Immunoprecipitation assays revealed that BEFV disrupts Beclin 1 and Bcl-2 interaction by JNK-mediated Bcl-2 phosphorylation, thereby activating autophagy. Overexpression of Bcl-2 reversed the BEFV-induced increase in the LC3 II levels. Suppression of autophagy either by knockdown of autophagy-related genes with shRNAs or treatment with a pharmacological inhibitor 3-MA reduced BEFV replication, suggesting that BEFV-induced autophagy benefits virus replication. Our results revealed that the BEFV M protein is one of the viral proteins involved in inducing autophagy via suppression of the PI3K/Akt/mTORC1 pathway. Furthermore, degradation of p62 was observed by immunoblotting, suggesting that BEFV infection triggers a complete autophagic response. Disruption of autophagosome-lysosome fusion by depleting LAMP2 resulted in reduction of virus yield, suggesting that formation of autolysosome benefits virus production.

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