Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 May 10;95(11):e00095-21.
doi: 10.1128/JVI.00095-21. Epub 2021 Mar 17.

CX3CR1 Engagement by Respiratory Syncytial Virus Leads to Induction of Nucleolin and Dysregulation of Cilia-related Genes

Christopher S Anderson  1 , Tatiana Chirkova  2 , Christopher G Slaunwhite  1 , Xing Qiu  3 , Edward E Walsh  4 , Larry J Anderson  5 , Thomas J Mariani  6
Affiliations

CX3CR1 Engagement by Respiratory Syncytial Virus Leads to Induction of Nucleolin and Dysregulation of Cilia-related Genes

Christopher S Anderson et al. J Virol. .

Abstract

Respiratory syncytial virus (RSV) contains a conserved CX3C motif on the ectodomain of the G-protein. The motif has been indicated as facilitating attachment of the virus to the host initiating infection via the human CX3CR1 receptor. The natural CX3CR1 ligand, CX3CL1, has been shown to induce signaling pathways resulting in transcriptional changes in the host cells. We hypothesize that binding of RSV to CX3CR1 via CX3C leads to transcriptional changes in host epithelial cells. Using transcriptomic analysis, the effect of CX3CR1 engagement by RSV was investigated. Normal human bronchial epithelial (NHBE) cells were infected with RSV virus containing either wildtype G-protein, or a mutant virus containing a CX4C mutation in the G-protein. RNA sequencing was performed on mock and 4-days-post-infected cultures. NHBE cultures were also treated with purified recombinant wild-type A2 G-protein. Here we report that RSV infection resulted in significant changes in the levels 766 transcripts. Many nuclear associated proteins were upregulated in the WT group, including nucleolin. Alternatively, cilia-associated genes, including CC2D2A and CFAP221 (PCDP1), were downregulated. The addition of recombinant G-protein to the culture lead to the suppression of cilia-related genes while also inducing nucleolin. Mutation of the CX3C motif (CX4C) reversed these effects on transcription decreasing nucleolin induction and lessening the suppression of cilia-related transcripts in culture. Furthermore, immunohistochemical staining demonstrated decreases in in ciliated cells and altered morphology. Therefore, it appears that engagement of CX3CR1 leads to induction of genes necessary for RSV entry as well as dysregulation of genes associated with cilia function.ImportanceRespiratory Syncytial Virus (RSV) has an enormous impact on infants and the elderly including increased fatality rates and potential for causing lifelong lung problems. Humans become infected with RSV through the inhalation of viral particles exhaled from an infected individual. These virus particles contain specific proteins that the virus uses to attach to human ciliated lung epithelial cells, initiating infection. Two viral proteins, G-protein and F-protein, have been shown to bind to human CX3CR1and nucleolin, respectively. Here we show that the G-protein induces nucleolin and suppresses gene transcripts specific to ciliated cells. Furthermore, we show that mutation of the CX3C-motif on the G-protein, CX4C, reverses these transcriptional changes.

PubMed Disclaimer

Figures

FIG 1
FIG 1
Changes in biological processes after RSV infection. (A) Top 10 biological processes and the associated genes that are significantly enriched in transcripts increased after RSV infection. (B) Top 10 biological processes and associated genes that are significantly enriched in transcripts decreased after RSV infection. Colors represent the biological processes described in the legend.
FIG 2
FIG 2
Changes in biological processes between wild-type and mutant RSV Infection. (A) Top 10 biological processes and associated genes that are significantly enriched in transcripts increased after wild-type RSV infection compared to mutant (CX4C) infection. (B) Top 10 biological processes and associated genes that are significantly enriched in transcripts decreased after wild-type RSV infection compared to mutant (CX4C) infection. Colors represent the biological processes described in the legend.
FIG 3
FIG 3
Effect of G protein on epithelial cell transcripts. (A to C) Transcript levels of expression after treatment of epithelial cell cultures with recombinant G protein for CC2D2A (A), CFAP331 (B), and nucleolin (C). Error bars represent standard error of the mean from averages of three subjects, with three replicates per subject per condition.
FIG 4
FIG 4
Ciliated cells after RSV infection. Quantification of the number of ciliated cells staining positive for acetylated tubulin per nucleus (DAPI, blue) in mock-infected or RSV-infected cultures. Averages represent three subjects, with three replicates per subject.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Fields BN, Knipe DM, Howley PM. 2013. Fields virology, 6th edition. Lippincott Williams & Wilkins, Philadephia, PA.
    1. Piedimonte G, Perez MK. 2014. Respiratory syncytial virus infection and bronchiolitis. Pediatr Rev 35:519–530. 10.1542/pir.35-12-519. - DOI - PMC - PubMed
    1. Shi T, McAllister DA, O'Brien KL, Simoes EAF, Madhi SA, Gessner BD, Polack FP, Balsells E, Acacio S, Aguayo C, Alassani I, Ali A, Antonio M, Awasthi S, Awori JO, Azziz-Baumgartner E, Baggett HC, Baillie VL, Balmaseda A, Barahona A, Basnet S, Bassat Q, Basualdo W, Bigogo G, Bont L, Breiman RF, Brooks WA, Broor S, Bruce N, Bruden D, Buchy P, Campbell S, Carosone-Link P, Chadha M, Chipeta J, Chou M, Clara W, Cohen C, de Cuellar E, Dang D-A, Dash-Yandag B, Deloria-Knoll M, Dherani M, Eap T, Ebruke BE, Echavarria M, de Freitas Lázaro Emediato CC, Fasce RA, Feikin DR, Feng L, RSV Global Epidemiology Network, et al. 2017. Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in young children in 2015: a systematic review and modelling study. Lancet 390:946–958. 10.1016/S0140-6736(17)30938-8. - DOI - PMC - PubMed
    1. Ali A, Lopardo G, Scarpellini B, Stein RT, Ribeiro D. 2020. Systematic review on respiratory syncytial virus epidemiology in adults and the elderly in Latin America. Int J Infect Dis 90:170–180. 10.1016/j.ijid.2019.10.025. - DOI - PMC - PubMed
    1. Han LL, Alexander JP, Anderson LJ. 1999. Respiratory syncytial virus pneumonia among the elderly: an assessment of disease burden. J Infect Dis 179:25–30. 10.1086/314567. - DOI - PubMed

LinkOut - more resources