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Interferon lambda inhibits dengue virus replication in epithelial cells.

Palma-Ocampo HK, Flores-Alonso JC, Vallejo-Ruiz V, Reyes-Leyva J, Flores-Mendoza L, Herrera-Camacho I, Rosas-Murrieta NH, Santos-López G - Virol. J. (2015)

Bottom Line: We found increased (~1.8 times) serological IFN-λ in dengue fever patients compared to healthy blood donors.IFN-λ inhibited DENV-2 replication in a dose-dependent manner in vitro.The reduction of viral titer corresponded with increased ISG mRNA levels (MX1 and OAS1), with the highest inhibition occurring at ISG's peak expression.

View Article: PubMed Central - PubMed

Affiliation: Laboratorio de Biología Molecular y Virología, Centro de Investigación Biomédica de Oriente, Instituto Mexicano del Seguro Social, Metepec, Puebla, México. hk.palma@gmail.com.

ABSTRACT

Background: In viral disease, infection is controlled at the cellular level by type I interferon (IFN-I), but dengue virus (DENV) has the ability to inhibit this response. Type III interferon, also known as lambda IFN (IFN-III or IFN-λ), is a complementary pathway to the antiviral response by IFN-I. This work analyzed the IFN-λ (IFN-III) mediated antiviral response against DENV serotype 2 (DENV-2) infection.

Methods: Dengue fever patients were sampled to determine their IFN-λ levels by ELISA. To study the IFN-λ response during DENV infection we selected the epithelial cell line C33-A, and we demonstrated that it is permissive to DENV-2 infection. The effect of IFN-λ on virus replication was determined in these cells, in parallel to the expression of IFN-stimulated genes (ISGs), and Suppressor of Cytokine Signaling (SOCS), genes measured by RT-qPCR.

Results: We found increased (~1.8 times) serological IFN-λ in dengue fever patients compared to healthy blood donors. IFN-λ inhibited DENV-2 replication in a dose-dependent manner in vitro. The reduction of viral titer corresponded with increased ISG mRNA levels (MX1 and OAS1), with the highest inhibition occurring at ISG's peak expression. Presence of IFN-negative regulators, SOCS1 and SOCS3, during DENV-2 infection was associated with reduced IFN-λ1 expression.

Conclusions: Evidence described here suggests that IFN-λ is a good candidate inhibitor of viral replication in dengue infection. Mechanisms for the cellular and organismal interplay between DENV and IFN- λ need to be further studied as they could provide insights into strategies to treat this disease. Furthermore, we report a novel epithelial model to study dengue infection in vitro.

No MeSH data available.


Related in: MedlinePlus

Transcription levels of IFN-stimulated genes during DENV-2 infection. Expression of OAS1 (a), MX1 (b), IFN-β (c), IFN-λ1 (d), SOCS1 (e), and SOCS3 genes (f) in cells infected with DENV-2 (MOI = 0.1) or treated with 10 ng/ml of IFN-λ1 or treated with IFN-λ1 before DENV-2 infection, were determined by RT-qPCR at 0, 6, 12, 18, 24, and 48 h post-infection or post-treatment. Results are presented as expression relative to untreated cells, which have a value of 1. mRNA levels were normalized to the HPRT gene. Data points represent the mean of three replicates and error bars indicate standard deviation
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Fig8: Transcription levels of IFN-stimulated genes during DENV-2 infection. Expression of OAS1 (a), MX1 (b), IFN-β (c), IFN-λ1 (d), SOCS1 (e), and SOCS3 genes (f) in cells infected with DENV-2 (MOI = 0.1) or treated with 10 ng/ml of IFN-λ1 or treated with IFN-λ1 before DENV-2 infection, were determined by RT-qPCR at 0, 6, 12, 18, 24, and 48 h post-infection or post-treatment. Results are presented as expression relative to untreated cells, which have a value of 1. mRNA levels were normalized to the HPRT gene. Data points represent the mean of three replicates and error bars indicate standard deviation

Mentions: Figure 8a shows that stimulation of C33-A cells with IFN-λ1 slightly increases the transcription of OAS1 to similar levels between 6 and 48 h post-treatment (pt). DENV-2 infection significantly increases OAS1 mRNA but at earlier times, peaking at 6 h post-infection. However, the most striking effect was present with IFN-λ1 pre-treatment followed by DENV-2 infection, that showed a pronounced increase in OAS1 expression from 6 to 18 h post-infection, at which time it peaked and then underwent a slow steady decrease, remaining high at 24 and 48 h. This result suggests that IFN-λ1 decreases DENV-2 replication in part by viral mRNA degradation via RNase L. Moreover, stimulation of cells with IFN-λ1 dramatically increases MX1 gene transcription, suggesting that the efficient activation of IFN-III signal transduction is useful in controlling DENV-2 infection. IFN-λ1 treatment induced a bimodal MX1 increase with a first peak at 6 h post-infection and a second peak nearly 100-fold higher than basal at 24 h (Fig. 8b). Bimodality probably is due as a result of a first wave of activation by IFN-β and IFN-λ1 and subsequently, the increase at 24 h could be by IFN-λ2, which has demonstrated late induction, as well as by the late wave of endogenous interferons [22]. MX1 mRNA was detected at similar levels in infected and non-infected cells at all the studied times, suggesting that DENV induces an impairment in IFN signal transduction; however, this experiment cannot discriminate between IFN-I or IFN-III specific pathways. In cells pre-treated with IFN-λ1 and then infected, MX1 mRNA increased between 18 and 48 h post-infection, although not as much as OAS1.Fig. 8


Interferon lambda inhibits dengue virus replication in epithelial cells.

Palma-Ocampo HK, Flores-Alonso JC, Vallejo-Ruiz V, Reyes-Leyva J, Flores-Mendoza L, Herrera-Camacho I, Rosas-Murrieta NH, Santos-López G - Virol. J. (2015)

Transcription levels of IFN-stimulated genes during DENV-2 infection. Expression of OAS1 (a), MX1 (b), IFN-β (c), IFN-λ1 (d), SOCS1 (e), and SOCS3 genes (f) in cells infected with DENV-2 (MOI = 0.1) or treated with 10 ng/ml of IFN-λ1 or treated with IFN-λ1 before DENV-2 infection, were determined by RT-qPCR at 0, 6, 12, 18, 24, and 48 h post-infection or post-treatment. Results are presented as expression relative to untreated cells, which have a value of 1. mRNA levels were normalized to the HPRT gene. Data points represent the mean of three replicates and error bars indicate standard deviation
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4584467&req=5

Fig8: Transcription levels of IFN-stimulated genes during DENV-2 infection. Expression of OAS1 (a), MX1 (b), IFN-β (c), IFN-λ1 (d), SOCS1 (e), and SOCS3 genes (f) in cells infected with DENV-2 (MOI = 0.1) or treated with 10 ng/ml of IFN-λ1 or treated with IFN-λ1 before DENV-2 infection, were determined by RT-qPCR at 0, 6, 12, 18, 24, and 48 h post-infection or post-treatment. Results are presented as expression relative to untreated cells, which have a value of 1. mRNA levels were normalized to the HPRT gene. Data points represent the mean of three replicates and error bars indicate standard deviation
Mentions: Figure 8a shows that stimulation of C33-A cells with IFN-λ1 slightly increases the transcription of OAS1 to similar levels between 6 and 48 h post-treatment (pt). DENV-2 infection significantly increases OAS1 mRNA but at earlier times, peaking at 6 h post-infection. However, the most striking effect was present with IFN-λ1 pre-treatment followed by DENV-2 infection, that showed a pronounced increase in OAS1 expression from 6 to 18 h post-infection, at which time it peaked and then underwent a slow steady decrease, remaining high at 24 and 48 h. This result suggests that IFN-λ1 decreases DENV-2 replication in part by viral mRNA degradation via RNase L. Moreover, stimulation of cells with IFN-λ1 dramatically increases MX1 gene transcription, suggesting that the efficient activation of IFN-III signal transduction is useful in controlling DENV-2 infection. IFN-λ1 treatment induced a bimodal MX1 increase with a first peak at 6 h post-infection and a second peak nearly 100-fold higher than basal at 24 h (Fig. 8b). Bimodality probably is due as a result of a first wave of activation by IFN-β and IFN-λ1 and subsequently, the increase at 24 h could be by IFN-λ2, which has demonstrated late induction, as well as by the late wave of endogenous interferons [22]. MX1 mRNA was detected at similar levels in infected and non-infected cells at all the studied times, suggesting that DENV induces an impairment in IFN signal transduction; however, this experiment cannot discriminate between IFN-I or IFN-III specific pathways. In cells pre-treated with IFN-λ1 and then infected, MX1 mRNA increased between 18 and 48 h post-infection, although not as much as OAS1.Fig. 8

Bottom Line: We found increased (~1.8 times) serological IFN-λ in dengue fever patients compared to healthy blood donors.IFN-λ inhibited DENV-2 replication in a dose-dependent manner in vitro.The reduction of viral titer corresponded with increased ISG mRNA levels (MX1 and OAS1), with the highest inhibition occurring at ISG's peak expression.

View Article: PubMed Central - PubMed

Affiliation: Laboratorio de Biología Molecular y Virología, Centro de Investigación Biomédica de Oriente, Instituto Mexicano del Seguro Social, Metepec, Puebla, México. hk.palma@gmail.com.

ABSTRACT

Background: In viral disease, infection is controlled at the cellular level by type I interferon (IFN-I), but dengue virus (DENV) has the ability to inhibit this response. Type III interferon, also known as lambda IFN (IFN-III or IFN-λ), is a complementary pathway to the antiviral response by IFN-I. This work analyzed the IFN-λ (IFN-III) mediated antiviral response against DENV serotype 2 (DENV-2) infection.

Methods: Dengue fever patients were sampled to determine their IFN-λ levels by ELISA. To study the IFN-λ response during DENV infection we selected the epithelial cell line C33-A, and we demonstrated that it is permissive to DENV-2 infection. The effect of IFN-λ on virus replication was determined in these cells, in parallel to the expression of IFN-stimulated genes (ISGs), and Suppressor of Cytokine Signaling (SOCS), genes measured by RT-qPCR.

Results: We found increased (~1.8 times) serological IFN-λ in dengue fever patients compared to healthy blood donors. IFN-λ inhibited DENV-2 replication in a dose-dependent manner in vitro. The reduction of viral titer corresponded with increased ISG mRNA levels (MX1 and OAS1), with the highest inhibition occurring at ISG's peak expression. Presence of IFN-negative regulators, SOCS1 and SOCS3, during DENV-2 infection was associated with reduced IFN-λ1 expression.

Conclusions: Evidence described here suggests that IFN-λ is a good candidate inhibitor of viral replication in dengue infection. Mechanisms for the cellular and organismal interplay between DENV and IFN- λ need to be further studied as they could provide insights into strategies to treat this disease. Furthermore, we report a novel epithelial model to study dengue infection in vitro.

No MeSH data available.


Related in: MedlinePlus