Intestinal epithelia activate anti-viral signaling via intracellular sensing of rotavirus structural components

Department of Pathology, Emory University, Atlanta, Georgia, USA.
Mucosal Immunology (Impact Factor: 7.37). 11/2010; 3(6):622-32. DOI: 10.1038/mi.2010.39
Source: PubMed


Rotavirus (RV), a leading cause of severe diarrhea, primarily infects intestinal epithelial cells (IECs) causing self-limiting illness. To better understand innate immunity to RV, we sought to define the extent to which IEC activation of anti-viral responses required viral replication or could be recapitulated by inactivated RV or its components. Using model human intestinal epithelia, we observed that RV-induced activation of signaling events and gene expression typically associated with viral infection was largely mimicked by administration of ultraviolet (UV)-inactivated RV. Use of anti-interferon (IFN) neutralizing antibodies revealed that such replication-independent anti-viral gene expression required type I IFN signaling. In contrast, RV-induction of nuclear factor-κB-mediated interleukin-8 expression was dependent on viral replication. The anti-viral gene expression induced by UV-RV was not significantly recapitulated by RV RNA or RV virus-like particles although the latter could enter IEC. Together, these results suggest that RV proteins mediate viral entry into epithelial cells leading to intracellular detection of RV RNA that generates an anti-viral response.

Download full-text


Available from: Sue E Crawford,
15 Reads
  • Source
    • "These molecules are typical of many viral infections including rotavirus. Viral dsRNA activate PRRs such as TLR3, RIG-I, and MDA-5, which signal host cellular responses in order to try to control viral infection [25-27]. IFNs and IFN-regulated gene products are then synthesized and play a key role in the host response for clearing viruses. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Previous findings suggested that Lactobacillus rhamnosus CRL1505 is able to increase resistance of children to intestinal viral infections. However, the intestinal cells, cytokines and receptors involved in the immunoregulatory effect of this probiotic strain have not been fully characterized. Results We aimed to gain insight into the mechanisms involved in the immunomodulatory effect of the CRL1505 strain and therefore evaluated in vitro the crosstalk between L. rhamnosus CRL1505, porcine intestinal epithelial cells (IECs) and antigen presenting cells (APCs) from swine Peyer’s patches in order to deepen our knowledge about the mechanisms, through which this strain may help preventing viral diarrhoea episodes. L. rhamnosus CRL1505 was able to induce IFN–α and –β in IECs and improve the production of type I IFNs in response to poly(I:C) challenge independently of Toll-like receptor (TLR)-2 or TLR9 signalling. In addition, the CRL1505 strain induced mRNA expression of IL-6 and TNF-α via TLR2 in IECs. Furthermore, the strain significantly increased surface molecules expression and cytokine production in intestinal APCs. The improved Th1 response induced by L. rhamnosus CRL1505 was triggered by TLR2 signalling and included augmented expression of MHC-II and co-stimulatory molecules and expression of IL-1β, IL-6, and IFN-γ in APCs. IL-10 was also significantly up-regulated by CRL1505 in APCs. Conclusions It was recently reviewed the emergence of TLR agonists as new ways to transform antiviral treatments by introducing panviral therapeutics with less adverse effects than IFN therapies. The use of L. rhamnosus CRL1505 as modulator of innate immunity and inductor of antiviral type I IFNs, IFN-γ, and regulatory IL-10 clearly offers the potential to overcome this challenge.
    BMC Microbiology 05/2014; 14(1):126. DOI:10.1186/1471-2180-14-126 · 2.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Type I and type II interferons (IFNs) play a critical role in control of a number of viral infections. To study whether altered and reduced functional capacities of type I and type II IFNs would affect rotavirus-induced diarrhea and viral replication, we obtained signal transducers and activators of transcription 1 (Stat1) knock-out mice (Stat1(-/-)) that lack many IFN-induced responses. We found that suckling Stat1(-/-) and immunocompetent mice orally infected with rotavirus experienced diarrhea and shed rotavirus with similar intensity. However, adult Stat1(-/-) mice shed up to 100-fold more homologous murine rotavirus and heterologous rhesus rotavirus antigen in their stools than did immunocompetent mice 2-6 days after infection. Clearance of rotavirus in stools from adult Stat1(-/-) mice occurred at the same time as in wild-type (WT) control mice. Clearance in Stat1(-/-) mice correlated with a potent antibody response and a mixed Th1 and Th2 response, whereas in WT control mice, clearance correlated with a weaker antibody response and a polarized Th1 response. Stat1(-/-) mice were fully protected against subsequent challenge. Moreover, vaccination of adult Stat1(-/-) mice with a rotavirus VP6 protein and the mucosal adjuvant Escherichia coli heat-labile toxin LT (R192G) elicited 94% protection, as measured by the total reduction in viral shedding for the group in comparison to unimmunized controls. Thus, modulating IFN function through the loss of Stat1 caused a defective innate immune response in adult mice but had no effect on rotavirus-induced diarrhea and replication in suckling mice. Furthermore, adult Stat1(-/-), IFN-gamma, and IFN-alpha/beta receptor(-/-) (IFNAR-2(-/-)) mice infected with rotavirus or vaccinated with VP6 vaccine and adjuvant were fully protected against rotavirus shedding following a subsequent challenge with rotavirus.
    Journal of Interferon & Cytokine Research 04/2003; 23(3):163-70. DOI:10.1089/107999003321532501 · 2.00 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Rotavirus (RV), a leading cause of diarrhea, primarily infects intestinal epithelial cells (IEC). Rotavirus-infected IEC produce IFN-β and express hundreds of IFN-dependent genes. We thus hypothesized that type 1 IFN plays a key role in helping IEC limit RV replication and/or protect against cell death. To test this hypothesis, we examined IEC (HT29 cells) infected with RV (MOI 1) ± neutralizing antibodies to IFN-α/β via microscopy and SDS-PAGE immunoblotting. We hypothesized that neutralization of IFN would be clearly detrimental to RV-infected IEC. Rather, we observed that blockade of IFN function rescued IEC from the apoptotic cell death that otherwise would have occurred 24-48 h following exposure to RV. This resistance to cell death correlated with reduced levels of viral replication at early time points (< 8 h) following infection and eventuated in reduced production of virions. The reduction in RV replication that resulted from IFN neutralization correlated with, and could be recapitulated by, blockade of IFN-induced protein kinase R (PKR) activation, suggesting involvement of this kinase. Interestingly, pharmacologic blockade of caspase activity ablated RV-induced apoptosis and dramatically increased viral protein synthesis, suggesting that IFN-induced apoptosis helps to control RV infection. These results suggest non-mutually exclusive possibilities that IFN signaling is usurped by RV to promote early replication and induction of cell death may be a means by which IFN signaling possibly clears RV from the intestine.
    Innate Immunity 07/2011; 18(2):294-306. DOI:10.1177/1753425911401930 · 3.27 Impact Factor
Show more