Woodsmoke particulates alter expression of antiviral host response genes in human nasal epithelial cells infected with SARS-CoV-2 in a sex-dependent manner

  1. Stephanie A. Brocke
  2. Grant T. Billings
  3. Sharon Taft-Benz
  4. Neil E. Alexis
  5. Mark T. Heise
  6. Ilona Jaspers

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Abstract

We have previously shown that exposure to particulate air pollution, both from natural and anthropogenic sources, alters gene expression in the airways and increases susceptibility to respiratory viral infection. Additionally, we have shown that woodsmoke particulates (WSP) affect responses to influenza in a sex-dependent manner. In the present study, we used human nasal epithelial cells (hNECs) from both sexes to investigate how particulate exposure could modulate gene expression in the context of SARS-CoV-2 infection. We used diesel exhaust particulate (DEP) as well as WSP derived from eucalyptus or red oak wood. HNECs were exposed to particulates at a concentration of 22 μg/cm 2 for 2 h then immediately infected with SARS-CoV-2 at a MOI (multiplicity of infection) of 0.5. Exposure to particulates had no significant effects on viral load recovered from infected cells. Without particulate exposure, hNECs from both sexes displayed a robust upregulation of antiviral host response genes, though the response was greater in males. However, WSP exposure before infection dampened expression of genes related to the antiviral host response by 72 h post infection. Specifically, red oak WSP downregulated IFIT1, IFITM3, IFNB1, MX1, CCL3, CCL5, CXCL11, CXCL10 , and DDX58 , among others. After sex stratification of these results, we found that exposure to WSP prior to SARS-CoV-2 infection downregulated anti-viral gene expression in hNECs from females more so than males. These data indicate that WSP, specifically from red oak, alter virus-induced gene expression in a sex-dependent manner and potentially suppress antiviral host defense responses following SARS-CoV-2 infection.

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    SciScore for 10.1101/2021.08.23.457411: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: Superficial nasal epithelial scrape biopsies were obtained from N=13 (7F, 6M) healthy, non-smoking adults with a Rhino-Pro curette (Arlington Scientific, Inc. 96-0900) per protocols approved by the University of North Carolina School of Medicine Institutional Review Board for Biomedical Research (protocol numbers 05-2528, 09-0716, 11-1363).
    Consent: Written informed consent was obtained from all study participants.
    Sex as a biological variableHNECs from three male and three female donors were used for each type of exposure (DEP, eucalyptus WSP, and red oak WSP).
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Experimental Models: Cell Lines
    SentencesResources
    Two hundred μl of each dilution was added to plated Vero E6 cells (C1008, ATCC) and incubated at 37°C.
    Vero E6
    suggested: RRID:CVCL_XD71)
    Software and Algorithms
    SentencesResources
    Viral titer data was analyzed using GraphPad Prism v. 8.4.0.
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)

    Results from OddPub: Thank you for sharing your code.

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    The fact that there were no differences in viral load recovered from exposed and unexposed hNECs, even at 72 h p.i., points at some potential limitations of the data presented here. The first is that the changes observed in gene expression at the transcript level may not translate into functional differences at the tissue level. Although IFIT1, IFITM3, IFNB1, IFNL1, IFNL2, MX1, CXCL10, DDX58, and other crucial genes for the antiviral response were all downregulated by particulate treatments (in hNECs from females), further investigation is necessary to determine whether these changes result in host defense decrements in vivo. Previously, we found agreement between transcript and protein level changes in gene expression after red oak woodsmoke exposure and LAIV inoculation in men and women (31). Further, while the respiratory epithelium represents the first line of defense to inhaled pollution and pathogens, clearance of infection and inhaled debris relies heavily upon recruitment and activation of immune cells. In our study, particulate treatment prior to infection decreased expression of several important chemokines by 72 h p.i. (Fig. 6). It is possible that in vivo, the WSP-induced reduction in expression of CCL3, CCL5, CXCL10, CXCL11, CXCL9, IL6, and TNF, all of which are chemoattractants for innate and adaptive immune cells, would result in a more widespread and lasting infection. In vivo exposures of mice to diesel exhaust prior to respiratory viral infection increased v...

    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.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

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  2. Version published to 10.1101/2021.08.23.457411v1 on bioRxiv