Development of Glycyrrhizinic Acid-Based Lipid Nanoparticle (LNP-GA) as An Adjuvant That Improves the Immune Response to Porcine Epidemic Diarrhea Virus Spike Recombinant Protein.

Porcine epidemic diarrhea virus (PEDV) has affected the pork industry worldwide and during outbreaks the mortality of piglets has reached 100%. Lipid nanocarriers are commonly used in the development of immunostimulatory particles due to their biocompatibility and slow-release delivery properties. In this study, we developed a lipid nanoparticle (LNP) complex based on glycyrrhizinic acid (GA) and tested its efficacy as an adjuvant in mice immunized with the recombinant N-terminal domain (NTD) of porcine epidemic diarrhea virus (PEDV) spike (S) protein (rNTD-S). The dispersion stability analysis (Z-potential -27.6 mV) confirmed the size and charge stability of the LNP-GA, demonstrating that the particles were homogeneously dispersed and strongly anionic, which favors nanoparticles binding with the rNTD-S protein, which showed a slightly positive charge (2.11 mV) by in silico analysis. TEM image of LNP-GA revealed nanostructures with a spherical-bilayer lipid vesicle (~100 nm). The immunogenicity of the LNP-GA-rNTD-S complex induced an efficient humoral response 14 days after the first immunization (p < 0.05) as well as an influence on the cellular immune response by decreasing serum TNF-α and IL-1ß concentrations, which was associated with an anti-inflammatory effect.

Comparative Review of the State of the Art in Research on the Porcine Epidemic Diarrhea Virus and SARS-CoV-2, Scope of Knowledge between Coronaviruses.

This review presents comparative information corresponding to the progress in knowledge of some aspects of infection by the porcine epidemic diarrhea virus (PEDV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) coronaviruses. PEDV is an alphacoronavirus of great economic importance due to the million-dollar losses it generates in the pig industry. PEDV has many similarities to the SARS-CoV-2 betacoronavirus that causes COVID-19 disease. This review presents possible scenarios for SARS-CoV-2 based on the collected literature on PEDV and the tools or strategies currently developed for SARS-CoV-2 that would be useful in PEDV research. The speed of the study of SARS-CoV-2 and the generation of strategies to control the pandemic was possible due to the knowledge derived from infections caused by other human coronaviruses such as severe acute respiratory syndrome (SARS) and middle east respiratory syndrome (MERS). Therefore, from the information obtained from several coronaviruses, the current and future behavior of SARS-CoV-2 could be inferred and, with the large amount of information on the virus that causes COVID-19, the study of PEDV could be improved and probably that of new emerging and re-emerging coronaviruses.

Phylogenetic and Molecular Analysis of the Porcine Epidemic Diarrhea Virus in Mexico during the First Reported Outbreaks (2013-2017).

The characteristics of the whole PEDV genome that has circulated in Mexico from the first outbreak to the present are unknown. We chose samples obtained from 2013 to 2017 and sequenced them, which enabled us to identify the genetic variation and phylogeny in the virus during the first four years that it circulated in Mexico. A 99% identity was found among the analyzed pandemic strains; however, the 1% difference affected the structure of the S glycoprotein, which is essential for the binding of the virus to the cellular receptor. The S protein induces the most efficacious antibodies; hence, these changes in structure could be implicated in the clinical antecedents of the outbreaks. Antigenic changes could also help PEDV avoid neutralization, even in the presence of previous immunity. The characterization of the complete genome enabled the identification of three circulating strains that have a deletion in ORF1a, which is present in attenuated Asian vaccine strains. The phylogenetic analysis of the complete genome indicates that the first PEDV outbreaks in Mexico were caused by INDEL strains and pandemic strains related to USA strains; however, the possibility of the entry of European strains exists, which may have caused the 2015 and 2016 outbreaks.

Predicted 3D model of the M protein of Porcine Epidemic Diarrhea Virus and analysis of its immunogenic potential.

The membrane protein M of the Porcine Epidemic Diarrhea Virus (PEDV) is the most abundant component of the viral envelope. The M protein plays a central role in the morphogenesis and assembly of the virus through protein interactions of the M-M, M-Spike (S) and M-nucleocapsid (N) type. The M protein is known to induce protective antibodies in pigs and to participate in the antagonistic response of the cellular antiviral system coordinated by the type I and type III interferon pathways. The 3D structure of the PEDV M protein is still unknown. The present work exposes a predicted 3D model of the M protein generated using the Robetta protocol. The M protein model is organized into a transmembrane and a globular region. The obtained 3D model of the PEDV M protein was compared with 3D models of the SARS-CoV-2 M protein created using neural networks and with initial machine learning-based models created using trRosetta. The 3D model of the present study predicted four linear B-cell epitopes (RSVNASSGTG and KHGDYSAVSNPSALT peptides are noteworthy), six discontinuous B-cell epitopes, forty weak binding and fourteen strong binding T-cell epitopes in the CV777 M protein. A high degree of conservation of the epitopes predicted in the PEDV M protein was observed among different PEDV strains isolated in different countries. The data suggest that the M protein could be a potential candidate for the development of new treatments or strategies that activate protective cellular mechanisms against viral diseases.

OX40 agonists for cancer treatment: a patent review.

INTRODUCTION: OX40 is an immune checkpoint in cancer and its presence in cancer is a good prognosis, making it a highly relevant target for the development of new immunotherapies. AREAS COVERED: The patent literature reveals vital information on new trends in cancer therapies. The authors used the patent databases of the six major patent offices in the world: United States Patent and Trademark Office, European Patent Office, World Intellectual Property Organization, Japan Patent Office, State Office of Intellectual Property of China and Korean Intellectual Property Office, to generate a panorama of patents related to OX40 agonists. Specific patents have been grouped into innovative patents and adoption patents. EXPERT OPINION: An increasing trend in the development of OX40 agonists in cancer, particularly in the years 2018 and 2019. United States was the leader in generating patents, followed by China and England. Major pharmaceutical companies have at least one anti-OX40 agonist, MEDI6469 and MEDI-0562 (AstraZeneca), PF-04518600 (Pfizer), GSK3174998 (GlaxoSmithKline), BMS-986,178 (Bristol-Myers Squibb) and MOXR0916 (Roche), which represent 68% of clinical trials conducted with OX40 agonists.

Immunoinformatics approach for predicting epitopes in HN and F proteins of Porcine rubulavirus.

Porcine rubulavirus (PRV), which belongs to the family Paramyxoviridae, causes blue eye disease in pigs, characterized by encephalitis and reproductive failure in newborn and adult pigs, respectively. There is no effective treatment against PRV and no information on the effectiveness of the available vaccines. Continuous outbreaks have occurred in Mexico since the early 1980s, which have caused serious economic losses to pig producers. Vaccination can be used to control this disease. Searching for effective antigen candidates against PRV, we first sequenced the PAC1 F protein, then we used various immunoinformatics tools to predict antigenic determinants of B-cells and T-cells against the two glycoproteins of the virus (HN and F proteins). Finally, we used AutoDock Vina to determine the binding energies. We obtained the F gene sequence of a PRV strain collected in the early 1990s in Mexico and compared its amino acid profile with previous and more recent strains, obtaining an identity similarity of 97.78 to 99.26%. For the F proteins, seven linear B-cell epitopes, six conformational B-cell epitopes and twenty-nine T-cell MHC class I epitopes were predicted. For the HN proteins, sixteen linear B-cell epitopes, seven conformational B-cell epitopes and thirty-four T-cell MHC class I epitopes were predicted. The ATRSETDYY and AAYTTTTCF epitopes of the HN protein might be important for neutralizing the viral infection. We determined the in silico binding energy between the predicted epitopes on the F and HN proteins and swine MHC-I molecules. The binding energy of these epitopes ranged from -5.8 to -7.8 kcal/mol. The present study aimed to assess the use of HN and F proteins as antigens, either as recombinant proteins or as a series of peptides that could activate different responses of the immune system. This may help identify relevant immunogens, saving time and costs in the development of new vaccines or diagnostic tools.

Five Novel Non-Sialic Acid-Like Scaffolds Inhibit In Vitro H1N1 and H5N2 Neuraminidase Activity of Influenza a Virus.

Neuraminidase (NA) of influenza viruses enables the virus to access the cell membrane. It degrades the sialic acid contained in extracellular mucin. Later, it is responsible for releasing newly formed virions from the membrane of infected cells. Both processes become key functions within the viral cycle. Therefore, it is a therapeutic target for research of the new antiviral agents. Structure-activity relationships studies have revealed which are the important functional groups for the receptor-ligand interaction. Influenza virus type A NA activity was inhibited by five scaffolds without structural resemblance to sialic acid. Intending small organic compound repositioning along with drug repurposing, this study combined in silico simulations of ligand docking into the known binding site of NA, along with in vitro bioassays. The five proposed scaffolds are N-acetylphenylalanylmethionine, propanoic 3-[(2,5-dimethylphenyl) carbamoyl]-2-(piperazin-1-yl) acid, 3-(propylaminosulfonyl)-4-chlorobenzoic acid, ascorbic acid (vitamin C), and 4-(dipropylsulfamoyl) benzoic acid (probenecid). Their half maximal inhibitory concentration (IC50) was determined through fluorometry. An acidic reagent 2'-O-(4-methylumbelliferyl)-α-dN-acetylneuraminic acid (MUNANA) was used as substrate for viruses of human influenza H1N1 or avian influenza H5N2. Inhibition was observed in millimolar ranges in a concentration-dependent manner. The IC50 values of the five proposed scaffolds ranged from 6.4 to 73 mM. The values reflect a significant affinity difference with respect to the reference drug zanamivir (p < 0.001). Two compounds (N-acetyl dipeptide and 4-substituted benzoic acid) clearly showed competitive mechanisms, whereas ascorbic acid reflected non-competitive kinetics. The five small organic molecules constitute five different scaffolds with moderate NA affinities. They are proposed as lead compounds for developing new NA inhibitors which are not analogous to sialic acid.

Histone H3K9 and H3K14 acetylation at the promoter of the LGALS9 gene is associated with mRNA levels in cervical cancer cells.

Galectin-9 levels have been reported to be altered in several cancer types, but the mechanism that regulates the expression of Galectin-9 has not been clarified. Galectin-9 is encoded by the LGALS9 gene, which gives rise to eight mRNA variants. The aims of this study were: (a) to identify the mRNA variants of LGALS9, (b) to characterize CpG methylation and H3K9 and H3K14 histone acetylation at the promoter of the LGALS9 gene, and (c) to characterize the relationship between these modifications and LGALS9 expression level in cervical cancer cells. All mRNA variants were detected in HaCaT (nontumoural keratinocytes) and SiHa cells, and seven were observed in HeLa cells. The promoter region of LGALS9 contains eight CpG dinucleotides. No hypermethylation pattern related to low LGALS9 expression was identified in tumour cells. Chromatin immunoprecipitation analysis demonstrated higher acetylation of H3K9ac and H3K14ac in HaCaT cells, which was related to higher mRNA levels. The presence of the mRNA variants suggests that alternative splicing may regulate the expression of galectin-9 isoforms. The results of this study suggest that histone acetylation, but not promoter CpG methylation, may be involved in the transcriptional regulation of the LGALS9 gene.

Colon carcinoma treatment using bispecific anti-GITR/CTLA-4 antibodies: a patent evaluation of WO2018091739.

Introduction: GITR is a receptor that increases the activation of T lymphocytes against tumor cells. There is a great need to discover and develop new therapies focused on activating GITR to increase the immune response in various types of cancer. The authors of WO2018091739 patent propose a method to eradicate cancer by using bispecific anti-GITR/anti-CTLA-4 antibodies.Areas covered: WO2018091739 patent describes anti-GITR/anti-CTLA-4 antibodies, pharmaceutical composition that contains it, and their application for cancer treatment, particularly colon carcinoma. Anti-GITR/anti-CTLA-4 antibodies are used at a dosage of 0.0003-3 mg antibody/kg patient weight and is suspended in an isotonic solution consisting of sodium phosphate, sucrose, NaCl, and polysorbate 80.Expert opinion: WO2018091739 only demonstrates that bispecific antibodies activate T cells, an antibody-dependent cellular cytotoxicity of CHO cells, and tumor inhibition in murine models of colon carcinoma. There are no clinical trials that show that treatment with bispecific antibodies can induce an antitumor response in cancer patients.

Cancer combinatorial immunotherapy using etigilimab and nivolumab: a patent evaluation of WO2018102536.

Introduction: TIGIT is an inhibitory receptor expressed by lymphocytes that suppresses the immune response against tumor cells. There is a great need to discover and develop new therapies focused on inhibiting the action of TIGIT and consequently improving the immune response in the various types of cancer. Authors of WO2018102536 patent propose a method to eradicate cancer utilizes anti-TIGIT antibody, etigilimab, in combination with anti-PD-1/PD-L1 antibody, nivolumab.Areas covered: WO2018102536 patent describes a method of cancer combinatorial treatment consisting of the utilization of either a pharmaceutical cocktail containing anti-TIGIT and an anti-PD-L1 antibody.Expert opinion: The results of the clinical trials only support trials regarding the tolerability of therapy with etigilimab, but does not show data related to the combined use of etigilimab and nivolumab.

Bispecific anti-OX40/CTLA-4 antibodies for advanced solid tumors: a patent evaluation of WO2018202649.

Introduction: OX40 is a potent costimulatory receptor of the immune response in various types of cancer and has been used as a target for the generation of agonists of its function. Authors of WO2018202649 patent propose a method to eradicate cancer using a bispecific antibodies against OX40/CTLA-4.Areas covered: WO2018202649 patent describes several bispecific antibodies capable of specifically binding to OX40 and CTLA-4 that target regulatory T cells in the tumor microenvironment.Expert opinion: WO2018202649 patent demonstrates that bispecific antibodies against OX40/CTLA-4 have anti-tumor activity against colon, pancreatic and bladder cancer, and that there is a synergistic action with anti-PD-1 antibodies for the treatment of colon cancer. However, there is no evidence to conclude that bispecific antibodies can be used in cancers other than colon, pancreas and bladder. Likewise, the patent only describes the application in combinatorial therapy with anti-PD-1 antibodies, without presenting data relative to the combination with other immunotherapeutic agents against other checkpoint targets.

Antiviral and immunomodulatory effects of polyphenols on macrophages infected with dengue virus serotypes 2 and 3 enhanced or not with antibodies.

Background: There is a lack of specific antiviral therapy against dengue virus (DENV) in current use. Therefore, a great proportion of dengue cases progress to severe clinical forms due to a complex interplay between virus and host immune response. It has been hypothesized that heterotypic non-neutralizing antibodies enhance DENV infection in phagocytic cells, and this induces an inflammatory response that is involved in the pathogenesis of severe dengue. Purpose: To identify the antiviral and immunomodulatory effects of polyphenols on dengue virus infection. Methods: Human U937-DC-SIGN macrophages were infected with DENV serotypes 2 or 3 in the presence or not of enhancing antibody 4G2. Viral titers and the secretion of tumor necrosis factor-alpha, IL-6, IL-10 and interferon-alpha were analyzed timely. Results: DENV infection alone induced high production of IL-6 and TNF-α, but in the presence of 4G2 antibody, viral titers and TNF-α secretion were potentiated. Based on anti-inflammatory antecedents, the polyphenols curcumin, fisetin, resveratrol, apigenin, quercetin and rutin were tested for antiviral and immunomodulatory properties. Only quercetin and fisetin inhibited DENV-2 and DENV-3 infection in the absence or presence of enhancing antibody (>90%, p<0.001); they also inhibited TNF-α and IL-6 secretion (p<0.001). Conclusion: Quercetin and fisetin down-regulate the production of proinflammatory cytokines induced by DENV infection enhanced by antibodies a mechanism involved in severe dengue.

Breast Cancer Subtypes Present a Differential Production of Reactive Oxygen Species (ROS) and Susceptibility to Antioxidant Treatment.

Due to their crucial role in cell metabolism and homeostasis, alterations in mitochondrial biology and function have been related to the progression of diverse diseases including cancer. One of the consequences associated to mitochondrial dysfunction is the production of reactive oxygen species (ROS). ROS are known to have a controversial role during cancer initiation and progression and although several studies have tried to manipulate intracellular ROS levels using antioxidants or pro-oxidation conditions, it is not yet clear how to target oxidation for cancer therapy. In this study, we found differences in mitochondrial morphology in breast cancer cells when compared to a non-tumorigenic cell line and differences in mitochondrial function among breast cancer subtypes when exploring gene-expression data from the TCGA tumor dataset. Interestingly, we found increased ROS levels in triple negative breast cancer (TNBC) cell lines and a dependency on ROS for survival since antioxidant treatment induced cell death in TNBC cells but not in an estrogen receptor positive (ER+) cell line. Moreover, we identified the mitochondria as the main source of ROS in TNBC cell lines. Our results indicate a potential use for ROS as a target for therapy in the TNBC subtype which currently has the worst prognosis among all breast cancers and remains as the only breast cancer subtype which lacks a targeted therapy.

Cancer immunotherapy using anti-TIM3/PD-1 bispecific antibody: a patent evaluation of EP3356411A1.

Introduction: TIM3 and PD-1 are checkpoint inhibitors in cancer that coordinate the downregulation of the proliferation of antigen-specific lymphocytes. There is a great need to discover and develop new therapies focused on inhibiting the action of TIM3 and PD-1 and consequently improving the immune response in the various types of cancer. The authors of patent EP3356411A1 propose several anti-TIM3/anti-PD-1 bispecific antibodies, as well as the method for producing them and their pharmacological application in the treatment of cancer. Areas covered: Patent EP3356411A1 describes a method by producing anti-TIM3/anti-PD-1 bispecific antibodies and their potential in cancer treatment. Expert opinion: Data supporting the patent demonstrate the ability by producing anti-TIM3/anti-PD-1 bispecific antibodies. Although the proposed methodology is very interesting and promising, further studies are necessary to assess the clinical applicability of the inventions on cancer.

Cancer combinatorial immunotherapy using anti-OX40 agonist and anti-PD-L1 antagonist: a patent evaluation of US2018256711A1.

Introduction: OX40 is checkpoint inhibitor in cancer that coordinates the downregulation of the proliferation of antigen-specific lymphocytes. There is a great need to discover and develop new therapies focused on inhibiting the action of OX40 and consequently improving the immune response in the various types of cancer. Authors of patent US2018256711A1 propose a method to eradicate cancer that utilizes anti-OX40 agonist antibody in combination with anti-PD-L1 antagonist antibody. Areas covered: Patent US2018256711A1 describes a method of cancer combinatorial treatment consisting of the utilization of a pharmaceutical cocktail containing anti-OX40 and an anti-PD-L1 antibody. Expert opinion: The results of the clinical trials only support trials regarding the tolerability of combinatorial therapy, even when the objectives of determining the safety and pharmacokinetics of the treatment are proposed.

Treatment of cancer with a combination of LAG-3Ig and anti-PD-1/anti-PD-L1 antibodies: a patent evaluation of US2018271940 A1.

INTRODUCTION: LAG-3 is checkpoint inhibitor in cancer that coordinates the down regulation of the proliferation of antigen-specific lymphocytes. There is a great need to discover and develop new therapies focused on inhibiting the action of LAG-3 and consequently improving the immune response in the various types of cancer. Authors of patent US2018271940 propose a method to eradicate cancer that utilizes the combination of LAG-3Ig and anti-PD-1 or anti-PD-L1 antibodies. Areas covered: Patent US2018271940 describes a method consisting of the utilization of either a pharmaceutical cocktail containing LAG-3Ig and an anti-PD-1 or anti-PD-L1 antibody for activation of T cells as a potential for the treatment of cancer. Expert opinion: Data supporting the patent demonstrate the ability of LAG-3Ig and PD-1/PD-L1 to be useful in T cells activation, in addition to the reports showing that LAG-3 and anti-PD-1 and PD-L1 antibodies are therapeutic agents against cancer. Although the proposed methodology is very interesting and promising, further studies are necessary to assess the clinical applicability of the inventions on cancer.

Neuraminidase activity of blue eye disease porcine rubulavirus: Specificity, affinity and inhibition studies.

Porcine rubulavirus (PorPV), also known as La Piedad Michoacan Virus (LPMV) causes encephalitis and reproductive failure in newborn and adult pigs, respectively. The hemagglutinin-neuraminidase (HN) glycoprotein is the most exposed and antigenic of the virus proteins. HN plays central roles in PorPV infection; i.e., it recognizes sialic acid-containing cell receptors that mediate virus attachment and penetration; in addition, its neuraminidase (sialic acid releasing) activity has been proposed as a virulence factor. This work describes the purification and characterization of PorPV HN protein (isolate PAC1). The specificity of neuraminidase is restricted to sialyl(α2,3)lactose (3SL). HN showed typical Michaelis-Menten kinetics with fetuin as substrate (km=0.029µM, Vmax=522.8nmolmin-1mg-1). When 3SL was used as substrate, typical cooperative kinetics were found (S50=0.15µM, Vmax=154.3nmolmin-1mg-1). The influenza inhibitor zanamivir inhibited the PorPV neuraminidase with IC50 of 0.24µM. PorPV neuraminidase was activated by Ca2+ and inhibited by nucleoside triphosphates with the level of inhibition depending on phosphorylation level. The present results open possibilities to study the role of neuraminidase in the pathogenicity of PorPV infection and its potential inhibitors.

Production of an enzymatically active and immunogenic form of ectodomain of Porcine rubulavirus hemagglutinin-neuraminidase in the yeast Pichia pastoris.

Blue-eye disease (BED) of swine is a viral disease endemic in Mexico. The etiological agent is a paramyxovirus classified as Porcine rubulavirus (PoRV-LPMV), which exhibits in its envelope the hemagglutinin-neuraminidase (HN) glycoprotein, the most immunogenic and a major target for vaccine development. We report in this study the obtaining of ectodomain of PoRV HN (eHN) through the Pichia pastoris expression system. The expression vector (pPICZαB-HN) was integrated by displacement into the yeast chromosome and resulted in a Mut(+) phenotype. Expressed eHN in the P. pastoris X33 strain was recovered from cell-free medium, featuring up to 67 nmol/min/mg after 6 days of expression. eHN was recognized by the serum of infected pigs with strains currently circulating in the Mexican Bajio region. eHN induces antibodies in mice after 28 days of immunization with specific recognition in ELISA test. These antibodies were able to inhibit >80% replication by viral neutralization assays in cell culture. These studies show the obtaining of a protein with similar characteristics to the native HN and which may be a candidate to propose a vaccine or to use the antigen in a serologic diagnostic test.

Upregulation of the Suppressors of Cytokine Signaling 1 and 3 Is Associated with Arrest of Phosphorylated-STAT1 Nuclear Importation and Reduced Innate Response in Denguevirus-Infected Macrophages.

To clarify whether the suppressors of cytokine signaling (SOCS) are associated with denguevirus (DENV) evasion of the antiviral response, we analyzed the expression kinetics of SOCS1 and SOCS3 and of the antiviral genes MxA and OAS during DENV infection of U937 macrophages that were or not treated with interferon (IFN)-α. DENV infection produced a viral titer three times higher in untreated than in IFN-α-treated cells (p < 0.001 at 72 h postinfection [p.i.]). Partial inhibition of DENV replication was associated with reduced expression of MxA and OAS antiviral genes as well as higher SOCS1 and SOCS3 expression in DENV-infected cells than in cells treated only with IFN-α. Complete loss of phosphorylated-signal transducer and activator of transcription (p-STAT)2 and reduced nuclear importation of p-STAT1 were observed in DENV-infected cells compared to IFN-α treatment that induced p-STAT1 and p-STAT2. Our data thus suggest that overexpression of SOCS1 and SOCS3 induced by DENV infection leads to impairment of antiviral response through the inhibition of STAT functionality.

Interferon lambda inhibits dengue virus replication in epithelial cells.

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.