Elucidation of the antiviral mechanism of cystine and theanine through transcriptome analysis of mice and comparison with COVID-19 gene set data

  1. Akira Mitsui
  2. Ryosei Sakai
  3. Kiyoshi Miwa
  4. Susumu Shibahara
  5. Shigekazu Kurihara
  6. Kenji Nagao

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Abstract

We previously showed that oral administration of cystine and theanine (CT) to mice confers resistance to influenza virus infection. In human studies, CT prevented colds in healthy subjects and enhanced antibody production after influenza vaccination in elderly individuals with a poor nutritional status. The mechanism of action of CT is thought to be glutathione (GSH)-mediated regulation of intracellular redox, which might affect innate immune systems such as macrophages to exert physiological effects. The effect of CT on influenza is independent of viral type, and this treatment has a broad range of antiviral activities. To explore the mechanisms of CT in viral infection, we performed transcriptome profiling of spleen tissues isolated from influenza A virus (IAV)-infected mice. We identified unique gene signatures in response to CT in the IAV-infected mice. Genes upregulated by CT included redox-regulated genes such as GCLC/GCLM (subunits of glutamate cysteine ligase, a rate-limiting enzyme of GSH biosynthesis), TXN1, TXN2, TXNRD2, and SOD1, suggesting that the intracellular redox environment is substantially altered by CT. However, genes downregulated in response to CT included chemokine/chemokine receptor genes (CCL5, CCL19, CXCL9, CXCL12, CXCR3, CXCR4, and ACKR3), some of which are related to cytokine storm. A comparison with public COVID-19-related gene set data showed that the upregulated gene signature was highly similar to the downregulated gene sets of SARS-CoV/SARS-CoV-2-infected cells and the upregulated gene set of attenuated SARS-CoV-infected cells. In conclusion, the unique gene signatures observed in response to orally administered CT in IAV-infected mouse spleen tissues suggested that CT may attenuate viral infection, replication and associated symptoms such as cytokine storm.

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  1. Version published to 10.1101/2020.06.25.149427v2 on bioRxiv
  2. ScreenIT

    SciScore for 10.1101/2020.06.25.149427: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIACUC: The study was performed according to protocols approved by the Institutional Ethical Committee for Animal Research and Institutional Biosafety Committee of Ajinomoto Co., Inc.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variableAnimal experiment: Five-week-old female BALB/c mice were purchased from Charles River Japan (Yokohama, Japan).

    Table 2: Resources

    Experimental Models: Organisms/Strains
    SentencesResources
    Animal experiment: Five-week-old female BALB/c mice were purchased from Charles River Japan (Yokohama, Japan).
    BALB/c
    suggested: RRID:IMSR_ORNL:BALB/cRl)
    Software and Algorithms
    SentencesResources
    RNA samples of each group were pooled, and the gene expression profile of the RNA samples was determined using GeneChip MG-U74Av2 arrays (Affymetrix) according to the manufacturer’s protocols.
    GeneChip
    suggested: None
    Enrichment analysis was performed using the enrichR package (version 2.1)[13]
    enrichR
    suggested: (Enrichr, RRID:SCR_001575)
    Among 420 gene sets (as of June, 2020), the gene sets for GSE147507[9] and GSE148729 and GSE30589[15] [NCBI’s Gene Expression Omnibus (GEO) Series IDs] (https://www.ncbi.nlm.nih.gov/geo/) were selected.
    Gene Expression Omnibus
    suggested: (Gene Expression Omnibus (GEO, RRID:SCR_005012)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Our study has some limitations. For instance, we compared IAV and IAV-CT samples and therefore did not observe transcriptome changes in response to CT alone. Although we showed the downregulation of chemokine genes and virus-responsive genes, these changes could be due to the reduction of IAV infection and/or replication. Further work is needed to clarify the detailed mechanisms of the antiviral effects of CT. In conclusion, the present study demonstrated the unique gene signatures in response to orally administered CT in IAV-infected mouse spleen tissues. Upregulated signatures included redox-related genes, and downregulated genes included chemokines. Based on a comparison with COVID-19-related public gene set data, CT may attenuate viral infection, replication and the cytokine storm related to COVID-19. Future clinical work is needed to confirm these findings.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • No funding statement was detected.
    • No protocol registration statement was detected.

    About SciScore

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  3. Version published to 10.1101/2020.06.25.149427v1 on bioRxiv