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Type I interferon response is delayed in human astrovirus infections.

Guix S, Pérez-Bosque A, Miró L, Moretó M, Bosch A, Pintó RM - PLoS ONE (2015)

Bottom Line: Type I interferon (IFN) activation and its subsequent effects are important in the response to viral infections.Here we show that human astroviruses (HAstVs), which are important agents of acute gastroenteritis in children, induce a mild and delayed IFN response upon infecting CaCo-2 cells.On the other hand, HAstV replication can be partially reduced by the addition of exogenous IFN, and inhibition of IFN activation by BX795 enhances viral replication, indicating that HAstVs are IFN-sensitive viruses.

View Article: PubMed Central - PubMed

Affiliation: Enteric Virus Group, Department of Microbiology, University of Barcelona, Barcelona, Spain; Nutrition and Food Safety Research Institute (INSA-UB), University of Barcelona, Santa Coloma de Gramanet, Spain.

ABSTRACT
Type I interferon (IFN) activation and its subsequent effects are important in the response to viral infections. Here we show that human astroviruses (HAstVs), which are important agents of acute gastroenteritis in children, induce a mild and delayed IFN response upon infecting CaCo-2 cells. Although IFN-β mRNA is detected within infected cells and supernatant from infected cells show antiviral activity against the replication of other well-known IFN-sensitive viruses, these responses occur at late stages of infection once genome replication has taken place. On the other hand, HAstV replication can be partially reduced by the addition of exogenous IFN, and inhibition of IFN activation by BX795 enhances viral replication, indicating that HAstVs are IFN-sensitive viruses. Finally, different levels of IFN response were observed in cells infected with different HAstV mutants with changes in the hypervariable region of nsP1a/4, suggesting that nsP1a/4 genotype may potentially have clinical implications due to its correlation with the viral replication phenotype and the antiviral responses induced within infected cells.

No MeSH data available.


Related in: MedlinePlus

Effect of exogenous IFN on HAstV replication.(A) IF analysis of CaCo-2 cells after a 24 h pre-treatment with 1,000 U IFN/ml and infection at different MOIs. (B) Quantitative measurement of HAstV, EMCV, and RV progeny release in the supernatant of untreated cells and IFN-treated cells. Data represent mean values of 2–3 independent experiments and error bars represent the SEM. Asterisk indicates a statistically significant difference between mean titers from untreated and IFN-treated samples (t-test) (p<0.001).
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pone.0123087.g005: Effect of exogenous IFN on HAstV replication.(A) IF analysis of CaCo-2 cells after a 24 h pre-treatment with 1,000 U IFN/ml and infection at different MOIs. (B) Quantitative measurement of HAstV, EMCV, and RV progeny release in the supernatant of untreated cells and IFN-treated cells. Data represent mean values of 2–3 independent experiments and error bars represent the SEM. Asterisk indicates a statistically significant difference between mean titers from untreated and IFN-treated samples (t-test) (p<0.001).

Mentions: In order to understand whether HAstV replication is sensitive to IFN, CaCo-2 cells were pre-treated with 1,000 U/ml of type I IFN for 24 hours before infection at three different MOIs. EMCV and and RV SA11 were used as controls for an IFN-sensitive virus and an IFN-resistant virus, respectively. The number of HAstV-infected cells observed by IF at 24 hpi was slightly reduced after IFN treatment (Fig 5A). Virus progeny released into the supernatant was measured for HAstV by qRT-PCR. EMCV and RV yields were measured by TCID50 titration in Vero and MA-104 cells, respectively. Reduction of HAstV replication after IFN pre-treatment was significant in all cases (p<0.001), but on average, there was a reduction of 0.8 ± 0.2 log, which was less than what was observed with EMCV (Fig 5B). As expected, RV was not affected by IFN-treatment.


Type I interferon response is delayed in human astrovirus infections.

Guix S, Pérez-Bosque A, Miró L, Moretó M, Bosch A, Pintó RM - PLoS ONE (2015)

Effect of exogenous IFN on HAstV replication.(A) IF analysis of CaCo-2 cells after a 24 h pre-treatment with 1,000 U IFN/ml and infection at different MOIs. (B) Quantitative measurement of HAstV, EMCV, and RV progeny release in the supernatant of untreated cells and IFN-treated cells. Data represent mean values of 2–3 independent experiments and error bars represent the SEM. Asterisk indicates a statistically significant difference between mean titers from untreated and IFN-treated samples (t-test) (p<0.001).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4383485&req=5

pone.0123087.g005: Effect of exogenous IFN on HAstV replication.(A) IF analysis of CaCo-2 cells after a 24 h pre-treatment with 1,000 U IFN/ml and infection at different MOIs. (B) Quantitative measurement of HAstV, EMCV, and RV progeny release in the supernatant of untreated cells and IFN-treated cells. Data represent mean values of 2–3 independent experiments and error bars represent the SEM. Asterisk indicates a statistically significant difference between mean titers from untreated and IFN-treated samples (t-test) (p<0.001).
Mentions: In order to understand whether HAstV replication is sensitive to IFN, CaCo-2 cells were pre-treated with 1,000 U/ml of type I IFN for 24 hours before infection at three different MOIs. EMCV and and RV SA11 were used as controls for an IFN-sensitive virus and an IFN-resistant virus, respectively. The number of HAstV-infected cells observed by IF at 24 hpi was slightly reduced after IFN treatment (Fig 5A). Virus progeny released into the supernatant was measured for HAstV by qRT-PCR. EMCV and RV yields were measured by TCID50 titration in Vero and MA-104 cells, respectively. Reduction of HAstV replication after IFN pre-treatment was significant in all cases (p<0.001), but on average, there was a reduction of 0.8 ± 0.2 log, which was less than what was observed with EMCV (Fig 5B). As expected, RV was not affected by IFN-treatment.

Bottom Line: Type I interferon (IFN) activation and its subsequent effects are important in the response to viral infections.Here we show that human astroviruses (HAstVs), which are important agents of acute gastroenteritis in children, induce a mild and delayed IFN response upon infecting CaCo-2 cells.On the other hand, HAstV replication can be partially reduced by the addition of exogenous IFN, and inhibition of IFN activation by BX795 enhances viral replication, indicating that HAstVs are IFN-sensitive viruses.

View Article: PubMed Central - PubMed

Affiliation: Enteric Virus Group, Department of Microbiology, University of Barcelona, Barcelona, Spain; Nutrition and Food Safety Research Institute (INSA-UB), University of Barcelona, Santa Coloma de Gramanet, Spain.

ABSTRACT
Type I interferon (IFN) activation and its subsequent effects are important in the response to viral infections. Here we show that human astroviruses (HAstVs), which are important agents of acute gastroenteritis in children, induce a mild and delayed IFN response upon infecting CaCo-2 cells. Although IFN-β mRNA is detected within infected cells and supernatant from infected cells show antiviral activity against the replication of other well-known IFN-sensitive viruses, these responses occur at late stages of infection once genome replication has taken place. On the other hand, HAstV replication can be partially reduced by the addition of exogenous IFN, and inhibition of IFN activation by BX795 enhances viral replication, indicating that HAstVs are IFN-sensitive viruses. Finally, different levels of IFN response were observed in cells infected with different HAstV mutants with changes in the hypervariable region of nsP1a/4, suggesting that nsP1a/4 genotype may potentially have clinical implications due to its correlation with the viral replication phenotype and the antiviral responses induced within infected cells.

No MeSH data available.


Related in: MedlinePlus