interleukin-8 and Dengue

The clinical consequences of SARS-CoV-2 and DENGUE virus co-infection are not promising. However, their treatment options are currently unavailable. Current studies have shown that quercetin is both resistant to COVID-19 and DENGUE; this study aimed to evaluate the possible functional roles and underlying mechanisms of action of quercetin as a potential molecular candidate against COVID-19 and DENGUE co-infection.. We used a series of bioinformatics analyses to understand and characterize the biological functions, pharmacological targets and therapeutic mechanisms of quercetin in COVID-19 and DENGUE co-infection.. We revealed the clinical characteristics of COVID-19 and DENGUE, including pathological mechanisms, key inflammatory pathways and possible methods of intervention, 60 overlapping targets related to the co-infection and the drug were identified, the protein-protein interaction (PPI) was constructed and TNFα, CCL-2 and CXCL8 could become potential drug targets. Furthermore, we disclosed the signaling pathways, biological functions and upstream pathway activity of quercetin in COVID-19 and DENGUE. The analysis indicated that quercetin could inhibit cytokines release, alleviate excessive immune responses and eliminate inflammation, through NF-κB, IL-17 and Toll-like receptor signaling pathway.. This study is the first to reveal quercetin as a pharmacological drug for COVID-19 and DENGUE co-infection. COVID-19 and DENGUE co-infection remain a potential threat to the world's public health system. Therefore, we need innovative thinking to provide admissible evidence for quercetin as a potential molecule drug for the treatment of COVID-19 and DENGUE, but the findings have not been verified in actual patients, so further clinical drug trials are needed.

Topics: Chemokine CCL2; Coinfection; COVID-19; COVID-19 Drug Treatment; Dengue; Dengue Virus; Humans; Interleukin-17; Interleukin-8; NF-kappa B; Protein Interaction Maps; Quercetin; SARS-CoV-2; Signal Transduction; Tumor Necrosis Factor-alpha

Dengue is the most common mosquito-borne flaviviral infection in the world today. Several factors contribute and act synergistically to cause severe infection. One of these is dysregulated host immunological mediators that cause transient pathophysiology during infection. These mediators act on the endothelium to increase vascular permeability, which leads to plasma leakage compromising hemodynamics and coagulopathy. We conducted a prospective study to explore the expression of pro- and anti-inflammatory cytokines and how they relate to clinical dengue manifestations, by assessing their dynamics through acute dengue infection in adults admitted to the Hospital for Tropical Diseases, Bangkok, Thailand. We performed cytokine analysis at three phases of infection for 96 hospitalized adults together with serotyping of confirmed dengue infection during the outbreaks of 2015 and 2016. The serum concentrations of seven cytokines (interleukin [IL]-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor alpha, and interferon gamma) were measured in duplicate using a commercial kit (Bio-Plex Human Cytokine Assay). In this study, the cytokine profile was suggestive of a T-helper 2 response. Most patients had secondary infection, and the levels of viremia were higher in patients with plasma leakage than those without plasma leakage. In addition, we observed that bleeding and hepatitis were associated with significantly higher levels of IL-8 during the early phases of infection. Furthermore, IL-6 levels in the early phase of infection were also elevated in bleeding patients with plasma leakage. These results suggest that IL-6 and IL-8 may act in synergy to cause bleeding in patients with plasma leakage.

Topics: Adult; Cytokines; Dengue; Female; Hemorrhage; Hepatitis, Viral, Human; Humans; Interferon-gamma; Interleukin-10; Interleukin-4; Interleukin-6; Interleukin-8; Male; Prospective Studies; Severe Dengue; Tumor Necrosis Factor-alpha; Viral Load

Dengue is a common infection, caused by dengue virus. There are four different dengue serotypes, with different capacity to cause severe dengue infections. Besides, secondary infections with heterologous serotypes, concurrent infections of multiple dengue serotypes may alter the severity of dengue infection. This study aims to compare the severity of single infection and concurrent infections of different combinations of dengue serotypes in-vitro. Human mast cells (HMC)-1.1 were infected with single and concurrent infections of multiple dengue serotypes. The infected HMC-1.1 supernatant was then added to human umbilical cord vascular endothelial cells (HUVEC) and severity of dengue infections was measured by the percentage of transendothelial electrical resistance (TEER). Levels of IL10, CXCL10 and sTRAIL in HMC-1.1 and IL-8, IL-10 and CXCL10 in HUVEC culture supernatants were measured by the ELISA assays. The result showed that the percentage of TEER values were significantly lower in single infections (p< 0.05), compared to concurrent infections on day 2 and 3, indicating that single infection increase endothelial permeability greater than concurrent infections. IL-8 showed moderate correlation with endothelial permeability (r > 0.4), indicating that IL-8 may be suitable as an in-vitro severity biomarker. In conclusion, this in-vitro model presented few similarities with regards to the conditions in dengue patients, suggesting that it could serve as a severity model to test for severity and levels of severity biomarkers upon different dengue virus infections.

Topics: Biomarkers; Chemokine CXCL10; Dengue; Dengue Virus; Human Umbilical Vein Endothelial Cells; Humans; Interleukin-10; Interleukin-8; Mast Cells; Serogroup; TNF-Related Apoptosis-Inducing Ligand

The macaque is widely accepted as a suitable model for preclinical characterization of dengue vaccine candidates. However, the only vaccine for which both preclinical and clinical efficacy results were reported so far showed efficacy levels that were substantially different between macaques and humans. We hypothesized that this model's predictive capacity may be improved using recent and minimally passaged dengue virus isolates, and by assessing vaccine efficacy by characterizing not only the post-dengue virus challenge viremia/RNAemia but also the associated-cytokine profile. Ten recent and minimally passaged Brazilian clinical isolates from the four dengue virus serotypes were tested for their infectivity in rhesus macaques. For the strains showing robust replication capacity, the associated-changes in soluble mediator levels, and the elicited dengue virus-neutralizing antibody responses, were also characterized. Three isolates from dengue virus serotypes 1, 2 and 4 induced viremia of high magnitude and longer duration relative to previously reported viremia kinetics in this model, and robust dengue virus-neutralizing antibody responses. Consistent with observations in humans, increased MCP-1, IFN-γ and VEGF-A levels, and transiently decreased IL-8 levels were detected after infection with the selected isolates. These results may contribute to establishing a dengue macaque model showing a higher predictability for vaccine efficacy in humans.

Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Brazil; Chemokine CCL2; Chlorocebus aethiops; Dengue; Dengue Virus; Down-Regulation; Interferon-gamma; Interleukin-8; Macaca mulatta; Serogroup; Up-Regulation; Vascular Endothelial Growth Factor A; Vero Cells

The skin is the first anatomical region that dengue virus (DENV) encounters during the natural infection. Although the role of some skin resident cells like dendritic cells and fibroblasts has been demonstrated to be crucial to elucidate the role of resident cells and molecules participating during the early events of the innate immune response, the participation of keratinocytes during DENV infection has not been fully elucidated. In this paper we aimed to evaluate the use of the HaCaT cell line as a model to study the immune responses of skin keratinocytes to DENV infection. We demonstrated productive DENV-2 infection of HaCaT cells and their capability to establish an antiviral response through production of type I and type III interferons (IFN-β and IFN-λ). The production of these cytokines by HaCaT cells correlated with upregulation of IFN-inducible transmembrane protein-3 (IFITM3) and viperin in bystander, uninfected cells. We also observed an increase in secretion of IL-6 and IL-8. Skin keratinocytes are known to secrete antimicrobial peptides (AMPs) during viral infections. In our model, DENV-2 infected HaCaT cells upregulate the production of cytoplasmic LL-37. We evaluated the dual role of LL-37, HBD2, and HBD3 antiviral activity and immunoregulation during DENV-2 infection of HaCaT cells and found that LL-37 significantly reduced DENV-2 replication. This indicates that the HaCaT cell line can be used as a model for studying the innate response of keratinocytes to DENV infection. Our results also suggest that skin keratinocytes play an important role in the skin microenvironment after DENV infection by secreting molecules like type I and type III IFNs, pro-inflammatory molecules, and LL-37, which may contribute to the protection against arboviral infections.

Topics: Antimicrobial Cationic Peptides; Cathelicidins; Cells, Cultured; Dendritic Cells; Dengue; Dengue Virus; Humans; Immunity, Innate; Interferons; Interleukin-6; Interleukin-8; Keratinocytes; Membrane Proteins; Oxidoreductases Acting on CH-CH Group Donors; Proteins; RNA-Binding Proteins; Skin; Up-Regulation

Severe dengue pathogenesis is not fully understood, but high levels of proinflammatory cytokines have been associated with dengue disease severity. In this study, the cytokine levels in 171 sera from Mexican patients with primary dengue fever (DF) and dengue haemorrhagic fever (DHF) from dengue virus (DENV) 1 (n = 116) or 2 (n = 55) were compared. DF and DHF were defined according to the patient's clinical condition, the primary infections as indicated by IgG enzymatic immunoassay negative results, and the infecting serotype as assessed by real-time reverse transcription-polymerase chain reaction. Samples were analysed for circulating levels of interleukin (IL)-12p70, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, IL-6, and IL-8 using a commercial cytometric bead array. Significantly higher IFN-γ levels were found in patients with DHF than those with DF. However, significantly higher IL-12p70, TNF-α, and IL-6 levels were associated with DHF only in patients who were infected with DENV2 but not with DENV1. Moreover, patients with DF who were infected with DENV1 showed higher levels of IL-12p70, TNF-α, and IL-6 than patients with DHF early after-fever onset. The IL-8 levels were similar in all cases regardless of the clinical condition or infection serotype. These results suggest that the association between high proinflammatory cytokine levels and dengue disease severity does not always stand, and it once again highlights the complex nature of DHF pathogenesis.

Topics: Cytokines; Dengue; Dengue Virus; Enzyme-Linked Immunosorbent Assay; Female; Humans; Inflammation Mediators; Interferon-gamma; Interleukin-12; Interleukin-6; Interleukin-8; Male; Mexico; Real-Time Polymerase Chain Reaction; Serogroup; Severe Dengue; Statistics, Nonparametric; Tumor Necrosis Factor-alpha

Dengue is responsible for a wide range of clinical manifestations, ranging from asymptomatic infections to severe cases. The alteration of cytokine levels correlated with clinical characteristics can help determine prognostic markers of the disease and the identification of targets for immunotherapy. We measured the viral load, serotype, and cytokine levels of 212 serum samples from patients with acute dengue infection during days 1-4 after the onset of symptoms. The patients were classified as either with hemorrhagic manifestations (HM) or with no hemorrhagic manifestations (NHM). The cytokines interleukin-6 (IL-6), IL-8, and IL-10 were increased (P < 0.05) in the dengue virus+ group, compared with the control group. A higher viral load (P < 0.05) and IL-6 was detected in the HM group compared with the NHM group. Interestingly, the NHM group demonstrated a significant positive correlation between inflammatory (IL-6 and 8) and anti-inflammatory (IL-10) cytokines, whereas the HM group did not. These findings suggest that a disturbance in the balance of inflammatory cytokines IL-6 and IL-8 with the anti-inflammatory cytokine, IL-10, combined with the high levels of IL-6 and viral load, characterize possible mechanisms related to the formation of HM.

Topics: Adolescent; Adult; Dengue; Dengue Virus; Female; Humans; Interleukin-10; Interleukin-6; Interleukin-8; Male; Middle Aged; RNA, Viral; Viral Load; Young Adult

About half of the world's population are living in the endemic area of dengue viruses implying that a rapid-mass vaccination may be required. In addition, a major target of dengue vaccine are children, thus, a needle-free administration is more attractive. These problems may be overcome by the alternative route of vaccination such as topical, oral and intranasal vaccination. Here, we investigated the possibility to deliver a dengue immunogen intranasally, a painless route of vaccination. The tested immunogen was the domain III of dengue serotype-3 E protein (EDIII-D3) loaded into trimethyl chitosan nanoparticles (EDIII-D3 TMC NPs). The primary human nasal epithelial cells, HNEpCs, were used as an in vitro model for nasal responses.. At tested concentrations, EDIII-D3 TMC NPs not only exerted no detectable toxicity toward HNEpC cultures but also efficiently delivered EDIII-D3 immunogens into HNEpCs. Moreover, HNEpCs quickly and strongly produced proinflammatory cytokines (IL-1β, IL-6, TNF-α), type-I IFN, the growth factors (GM-CSF, IL-7), the chemokines (MCP-1, MIP-1β, IL-8), Th1-related cytokines (IL-2, IL-12p70, IL-17, IFN-γ) and Th2-related cytokine (IL-4) in response to EDIII-D3 TMC NPs treatment.. A potential mucosal delivery system for dengue immunogens was revealed and found to stimulate a strong local innate antiviral response which possibly leading to a systemic adaptive immunity.

Topics: Administration, Intranasal; Dengue; Dengue Vaccines; Dengue Virus; Epithelial Cells; Humans; Interleukin-2; Interleukin-8; Nose; Th1 Cells; Th2 Cells; Vaccination; Viral Envelope Proteins; Viral Vaccines

Increased serum and mRNA levels of cytokines in patients with dengue virus (DV) infection suggest that cytokines are one of the key factors in the pathogenesis of disease caused by this virus. Here, we tested 211 serum and 56 mRNA samples from an equal number of dengue cases to determine the levels of interleukin-8 (IL-8), interferon gamma (IFN-γ), interleukin-10 (IL-10) and transforming growth factor beta (TGF-β). A total 70 serum and 15 mRNA samples from healthy individual were also tested for cytokines and served as controls. Serum and mRNA levels of IL-8 were highest in the earlier days of dengue infection. IFNγ levels peaked one or two days before defervescence. Levels of IL-10 and TGF-β were highest later in dengue infection, and TGF-β levels peaked on the day of defervescence. Mean levels of IFNγ, TGF β and IL-10 were higher in samples from dengue cases, irrespective of severity, than in healthy controls. In contrast, the level of IL-8 was significantly higher in samples from severe dengue cases and lower in cases of dengue without warning signs than in healthy controls. Children (82.2 % of 101 paediatric cases) commonly had severe dengue illness. Samples that were positive for anti-DV IgG antibody had higher levels of IL-8 and TGF β. DV-2 infections were associated with severe dengue illness. IL-8 and IFNγ levels were higher in the presence of warning signs of severe dengue. Levels of IL-8, IL-10 and TGF β were independently associated with disease outcome. These data provide evidence of an association of IL-8, IFNγ, TGF β and IL-10 levels with the severity of dengue illness. Especially, IL-8 levels can be used as a predictor of severe DV infection.

Topics: Adolescent; Adult; Case-Control Studies; Child; Child, Preschool; Dengue; Enzyme-Linked Immunosorbent Assay; Female; Gene Expression; Humans; Infant; Infant, Newborn; Interferon-gamma; Interleukin-10; Interleukin-8; Male; Real-Time Polymerase Chain Reaction; Severity of Illness Index; Transforming Growth Factor beta; Young Adult

Dengue, a serious viral infection caused by the mosquito vector, Aedes aegyptii, affects about 390 million people annually from more than 125 countries across the globe. However, until now, there is no reliable clinical or laboratory indicator to accurately predict the development of dengue severity. Here, we explored critical pathophysiological determinants like IL8, circulating immune complex (CIC) and cryoglobulin in dengue-infected patients for identification of novel dengue severity biomarker(s). Totally, 100 clinically suspected dengue cases were tested by NS1 ELISA and MAC ELISA for dengue virus aetiology. For control, 49 healthy volunteers were included. Blood profiling (complete hemogram and liver function test) of patient population were done using automated cell counter and standard auto analyzer based biochemical analysis. Serum CIC was quantified by PEG precipitation. Serum cryoglobulins were estimated by Folin assay. Levels of serum IL-8 were assessed by standard sandwich ELISA kits. Patient CIC were further characterized by SDS Gel electrophoresis. Forty per cent of the cases tested positive, of which 11 patients had severe clinical manifestation. The mean ±SEM of cryoglobulin concentration for DHF, DF, and HC were 1.30 ± 0.31, 0.59 ± 0.08 and 0.143 ± 0.009 μg/μl, respectively. Thus, DHF and DF patients have shown 9- and 2.2-fold increase in cryoglobulin levels; and 18- and 5-fold increased CIC, respectively compared to HC patients. The mean ±SEM of CIC-PEG index for DHF, DF and HC were 491 ± 41.22, 146 ± 14.19 and 27.98 ± 2.56, respectively. Raised levels of IL8 titers were also found in all 11 DHF patients. Peak levels of CIC, cryoglobulin and IL8 titers were associated with thrombocytopenia. SDS PAGE analysis of CIC from DHF revealed the presence of at least six protein bands that were not observed in samples from DF and HC. Prediction efficacy of IL8, CIC and cryoglobulin for DHF was determined using the receiver operator characteristic curve (ROC). The area under the curve was 1.00 for IL8, 0.99 for CIC and 0.74 for cryoglobulins. Overall, the results suggest that CIC, IL-8 and cryoglobulins may serve as important laboratory parameters to monitor dengue infection progression.

Topics: Antigen-Antibody Complex; Cryoglobulins; Dengue; Female; Humans; Interleukin-8; Male

Dengue is the most prevalent human arbovirus disease in the world. Dengue infection has a large spectrum of clinical manifestations, from self-limited febrile illness to severe syndromes accompanied by bleeding and shock. Thrombocytopenia and vascular leak with altered cytokine profiles in plasma are features of severe dengue. Although monocytes have been recognized as important sources of cytokines in dengue, the contributions of platelet-monocyte interactions to inflammatory responses in dengue have not been addressed. Patients with dengue were investigated for platelet-monocyte aggregate formation. Platelet-induced cytokine responses by monocytes and underlying mechanisms were also investigated in vitro. We observed increased levels of platelet-monocyte aggregates in blood samples from patients with dengue, especially patients with thrombocytopenia and increased vascular permeability. Moreover, the exposure of monocytes from healthy volunteers to platelets from patients with dengue induced the secretion of the cytokines IL-1β, IL-8, IL-10 and MCP-1, whereas exposure to platelets from healthy volunteers only induced the secretion of MCP-1. In addition to the well-established modulation of monocyte cytokine responses by activated platelets through P-selectin binding, we found that interaction of monocytes with apoptotic platelets mediate IL-10 secretion through phosphatidylserine recognition in platelet-monocyte aggregates. Moreover, IL-10 secretion required platelet-monocyte contact but not phagocytosis. Together, our results demonstrate that activated and apoptotic platelets aggregate with monocytes during dengue infection and signal specific cytokine responses that may contribute to the pathogenesis of dengue.

Topics: Adult; Apoptosis; Blood Platelets; Capillary Permeability; Chemokine CCL2; Dengue; Dengue Virus; Female; Humans; Inflammation; Interleukin-10; Interleukin-1beta; Interleukin-8; Male; Monocytes; P-Selectin; Phagocytosis; Phosphatidylserines; Platelet Activation; Thrombocytopenia

Dengue virus (DENV) infection could lead to dengue fever (DF), dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). The disease outcome is controlled by both viral and host factors. Inflammation mediators from DENV-infected cells could contribute to increased vascular permeability, leading to severe DHF/DSS. Therefore, suppression of inflammation could be a potential therapeutic approach for treatment of dengue patients. In this context, p38 MAPK (mitogen-activated protein kinase) is a key enzyme that modulates the initiation of stress and inflammatory responses. Here we show that SB203580, a p38 MAPK inhibitor, suppressed the over production of DENV-induced pro-inflammatory mediators such as TNF-α, IL-8, and RANTES from human PBMCs, monocytic THP-1, and granulocyte KU812 cell lines. Oral administration of SB203580 in DENV-infected AG129 mice prevented hematocrit rise and lymphopenia, limited the development of inflammation and pathology (including intestine leakage), and significantly improved survival. These results, for the first time, have provided experimental evidence to imply that a short term inhibition of p38 MAPK may be beneficial to reduce disease symptoms in dengue patients.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Capillary Permeability; Cell Line; Chemokine CCL5; Cricetinae; Culicidae; Dengue; Dengue Virus; Enzyme Inhibitors; Hematocrit; Humans; Imidazoles; Inflammation; Interleukin-8; Lymphopenia; Mice; p38 Mitogen-Activated Protein Kinases; Pyridines; Tumor Necrosis Factor-alpha

We investigated the roles of IFN regulatory factor (IRF)-3 and IRF-7 in innate antiviral immunity against dengue virus (DENV). Double-deficient Irf-3(-/-)7(-/-) mice infected with the DENV2 strain S221 possessed 1,000-150,000 fold higher levels of viral RNA than wild-type and single-deficient mice 24 h postinfection (hpi); however, they remained resistant to lethal infection. IFN-α/β was induced similarly in wild-type and Irf-3(-/-) mice post-DENV infection, whereas in the Irf-7(-/-) and Irf-3(-/-)7(-/-) mice, significantly low levels of IFN-α/β expression was observed within 24 hpi. IFN-stimulated gene induction was also delayed in Irf-3(-/-)7(-/-) mice relative to wild-type and single-deficient mice. In particular, Cxcl10 and Ifnα2 were rapidly induced independently of both IRF-3 and IRF-7 in the Irf-3(-/-)7(-/-) mice with DENV infection. Higher levels of serum IFN-γ, IL-6, CXCL10, IL-8, IL-12 p70, and TNF were also observed in Irf-3(-/-)7(-/-) mice 24 hpi, at which time point viral titers peaked and started to be cleared. Ab-mediated blockade experiments revealed that IFN-γ, CXCL10, and CXCR3 function to restrict DENV replication in Irf-3(-/-)7(-/-) mice. Additionally, the IFN-stimulated genes Cxcl10, Ifit1, Ifit3, and Mx2 can be induced via an IRF-3- and IRF-7-independent pathway that does not involve IFN-γ signaling for protection against DENV. Collectively, these results demonstrate that IRF-3 and IRF-7 are redundant, albeit IRF-7 plays a more important role than IRF-3 in inducing the initial IFN-α/β response; only the combined actions of IRF-3 and IRF-7 are necessary for efficient control of early DENV infection; and the late, IRF-3- and IRF-7-independent pathway contributes to anti-DENV immunity.

Topics: Adaptor Proteins, Signal Transducing; Aedes; Animals; Carrier Proteins; Cell Line; Chemokine CXCL10; Dengue; Dengue Virus; Immunity, Innate; Interferon Regulatory Factor-3; Interferon Regulatory Factor-7; Interferon-alpha; Interferon-beta; Interferon-gamma; Interleukin-12; Interleukin-6; Interleukin-8; Intracellular Signaling Peptides and Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Myxovirus Resistance Proteins; Proteins; Receptors, CXCR3; RNA-Binding Proteins; RNA, Viral; Signal Transduction; Tumor Necrosis Factors; Viral Load; Virus Replication

Dengue virus (DENV) causes self‑limiting dengue fever (DF), severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). It is generally considered that cytokine storm leads to the increased plasma leakage characteristic of DHF/DSS. In the present study, peripheral blood mononuclear cells (PBMCs) were isolated from blood samples of healthy volunteers and infected with DENV serotype 2 (DENV2). Culture supernatants of DENV2‑infected and -uninfected PBMCs were analyzed using a human cytokine array. Between a 6‑12 h post‑infection, levels of CCL5, IL‑6 and IL‑8 were markedly elevated, while those of TNF‑α decreased. Total RNA isolated from these PBMCs was analyzed by human miRNA microarray to identify differentially expressed microRNAs (miRNAs). Quantitative reverse transcription polymerase chain reaction was used to validate 11 upregulated and 4 downregulated miRNAs. Sanger mibase, miRanda and TargetScan were used to identify 261 common predicted genes. Databases were used to identify homologous sequences on mRNAs of putative target genes that may be directly bound by the miRNAs identified. We found that cytokines and epigenetic regulators may be putative target genes of these miRNAs. Using ingenuity pathway analysis, we noted that canonical pathways, including biological regulation, may be modulated by these miRNAs.

Topics: Cells, Cultured; Chemokine CCL5; Computational Biology; Databases, Genetic; Dengue; Dengue Virus; Down-Regulation; Gene Expression Profiling; Humans; Interleukin-6; Interleukin-8; Leukocytes, Mononuclear; MicroRNAs; Oligonucleotide Array Sequence Analysis; Severe Dengue; Tumor Necrosis Factor-alpha; Untranslated Regions; Up-Regulation

Identification of early determinants of dengue disease progression, which could potentially enable individualized patient care are needed at present times. Soluble ST2 (sST2) has been recently reported to be elevated in the serum of children older than 2 years old and adults with dengue infection and it was correlated with secondary infections as well as with severe presentations of the disease. The mechanism by which secreted ST2 is linked to severe dengue and plasma leakage remains unclear. One possibility is that IL-33 ligand may be elevated, contributing to membrane bound ST2 as part of the immune activation in dengue infection. We determined plasma levels of sST2 and the ligand IL-33 in 66 children with acute secondary dengue infections clinically classified using the guidelines of the World Health Organization, 2009. Dengue infection showed significant increases in cytokines IL-12p70, IL-10, IL-8, IL-6, IL-1β and TNFα measured by flow cytometry based assay compared to uninfected individuals. In contrast, IL-33 levels remained unchanged between infected and uninfected individuals. The levels of sST2 positively correlated with values of IL-6 and IL-8 and inversely correlated with number of median value of platelet levels. In addition to circulating cytokine positive correlations we found that sST2 and isoenzyme creatine kinase-MB (CK-MB), a marker of myocardial muscle damage present in severe dengue cases were associated. Our pediatric study concluded that in dengue infections sST2 elevation does not involve concomitant changes of IL-33 ligand. We propose a study to assess its value as a predictor factor of disease severity.

Topics: Adult; Child; Child, Preschool; Cohort Studies; Demography; Dengue; Female; Humans; Interleukin-1 Receptor-Like 1 Protein; Interleukin-33; Interleukin-6; Interleukin-8; Interleukins; Ligands; Male; Receptors, Cell Surface; Severity of Illness Index; Solubility

Hepatocytes are one of the important targets in dengue virus (DV) infection. Chemokines produced in DV infection play important immunopathogenic roles. We previously showed that DV infection can directly activate signal transducer and activator of transcription 3 (STAT3) in dendritic cells. In the present study, we examined the possible involvement of the Janus kinase (JAK)/STAT3 pathway in chemokine production from DV-infected hepatocytes. HepG2 cells were infected by DV. The activation of STAT3, nuclear factor-kappaB (NF-κB) and other transcription factors was determined by Western blotting or electrophoretic mobility shift assay. The concentrations of chemokines were measured by enzyme-linked immunosorbent assay. Virus titers were determined by plaque assays. A genetic manipulation with short hairpin RNA (shRNA) was applied to knock-down STAT3. Chemotaxis assays were used to evaluate cell migration. We observed that DV infection induced phosphorylation of STAT3 and its DNA-binding activity and such effects were attenuated by the inhibitor of JAK2 or JAK3. Blocking JAK2 or JAK3 reduced DV-induced cell migration and production of chemokines like interleukin-8 and regulated upon activation, normal T-cell expressed and secreted (RANTES). At high doses, the JAK2 but not JAK3 inhibitor could significantly inhibit DV production. Knocking down STAT3 with shRNA suppressed DV-induced STAT3, NF-κB and AP-1 activation. Furthermore, reduction of STAT3 suppressed DV-induced chemokine production and cell migration but had no effect on virus production. In conclusion, the results show that the JAK/STAT3 pathway is critical in chemokine production from DV-infected hepatocytes. Targeting this pathway may be of benefit in the therapy of DV-induced immunopathologies.

Topics: Activating Transcription Factor 3; Blotting, Western; Chemokine CCL5; Chemokines; Dengue; Dengue Virus; Electrophoretic Mobility Shift Assay; Hep G2 Cells; Humans; Interleukin-8; Janus Kinase 2; Janus Kinase 3; Janus Kinases; Signal Transduction; STAT3 Transcription Factor

The host response to dengue virus infection is characterized by the production of numerous cytokines, but the overall picture appears to be complex. It has been suggested that a balance may be involved between protective and pathologic immune responses. This study aimed to define differential immune responses in association with clinical outcomes by gene expression profiling of a selected panel of inflammatory genes in whole blood samples from children with severe dengue infections.. Whole blood mRNA from 56 Indonesian children with severe dengue virus infections was analyzed during early admission and at day -1, 0, 1, and 5-8 after defervescence. Levels were related to baseline levels collected at a 1-month follow-up visit. Processing of mRNA was performed in a single reaction by multiplex ligation-dependent probe amplification, measuring mRNA levels from genes encoding 36 inflammatory proteins and 14 Toll-like receptor (TLR)-associated molecules. The inflammatory gene profiles showed up-regulation during infection of eight genes, including IFNG and IL12A, which indicated an antiviral response. On the contrary, genes associated with the nuclear factor (NF)-kappaB pathway were down-regulated, including NFKB1, NFKB2, TNFR1, IL1B, IL8, and TNFA. Many of these NF-kappaB pathway-related genes, but not IFNG or IL12A, correlated with adverse clinical events such as development of pleural effusion and hemorrhagic manifestations. The TLR profile showed that TLRs were differentially activated during severe dengue infections: increased expression of TLR7 and TLR4R3 was found together with a decreased expression of TLR1, TLR2, TLR4R4, and TLR4 co-factor CD14.. These data show that different immunological pathways are differently expressed and associated with different clinical outcomes in children with severe dengue infections.

Topics: Adolescent; Child; Child, Preschool; Dengue; Dengue Virus; Female; Gene Expression Profiling; Gene Expression Regulation; Humans; Immunity, Innate; Interleukin-12 Subunit p35; Interleukin-8; Male; NF-kappa B; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Severe Dengue; Signal Transduction; Toll-Like Receptors

In vitro infection with dengue virus induces interleukin (IL)-8 secretion, which increases endothelial cell permeability; this has been proposed as a mechanism for plasma leakage in dengue hemorrhagic fever. We studied the mechanisms of IL-8 induction, using luciferase reporter constructs, and the effect of pharmacological inhibitors of either IL-8 secretion or nuclear factor- kappa B (NF-kappa B) activation on IL-8 induction by dengue 2 virus (DEN2V) infection. IL-8 induction by DEN2V infection was associated with activation of NF- kappa B and activator protein-1 (AP-1) in HEK293A cells but only with activation of AP-1 in HepG2 cells. Treatment with SB203580, a mitogen-activated protein kinase inhibitor, and rolipram, a phosphodiesterase IV inhibitor, partially inhibited DEN2V-induced IL-8 secretion in HEK293A cells but increased DEN2V-induced IL-8 secretion in HepG2 cells. In contrast, treatment with dexamethasone increased DEN2V-induced IL-8 secretion in HEK293A cells but had no effect on DEN2V-induced IL-8 secretion in HepG2 cells. These results demonstrate that anti-inflammatory drugs have variable effects on IL-8 secretion in different cell types during DEN2V infection.

Topics: Cell Line; Cell Line, Tumor; Dengue; Dengue Virus; Dexamethasone; DNA, Recombinant; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Gene Expression; Genes, Reporter; Glucocorticoids; Humans; Imidazoles; Interleukin-8; Luciferases; NF-kappa B; Phosphodiesterase Inhibitors; Pyridines; Rolipram; Transcription Factor AP-1

Elevated circulating levels of chemokines have been reported in patients with dengue fever and are proposed to contribute to the pathogenesis of dengue disease. To establish in vitro models for chemokine induction by dengue 2 virus (DEN2V), we studied a variety of human cell lines and primary cells. DEN2V infection of HepG2 and primary dendritic cells induced the production of interleukin-8 (IL-8), RANTES, MIP-1alpha, and MIP-1beta, whereas only IL-8 and RANTES were induced following dengue virus infection of HEK293 cells. Chemokine secretion was accompanied by an increase in steady-state mRNA levels. No chemokine induction was observed in HEK293 cells treated with poly(I:C) or alpha interferon, suggesting a direct effect of virus infection. To determine the mechanism(s) involved in the induction of chemokine production by DEN2V, individual dengue virus genes were cloned into plasmids and expressed in HEK293 cells. Transfection of a plasmid expressing NS5 or a dengue virus replicon induced IL-8 gene expression and secretion. RANTES expression was not induced under these conditions, however. Reporter assays showed that IL-8 induction by NS5 was principally through CAAT/enhancer binding protein, whereas DEN2V infection also induced NF-kappaB. These results indicate a role for the dengue virus NS5 protein in the induction of IL-8 by DEN2V infection. Recruitment and activation of potential target cells to sites of DEN2V replication by virus-induced chemokine production may contribute to viral replication as well as to the inflammatory components of dengue virus disease.

Topics: CCAAT-Enhancer-Binding Proteins; Cells, Cultured; Dengue; Dengue Virus; Humans; Interleukin-8; RNA, Messenger; RNA, Viral; Viral Nonstructural Proteins

Permeability alterations of microvascular endothelia may be a factor in the plasma leakage produced by dengue virus infection. Confluent monolayers of the human dermal microvascular endothelial cell line HMEC-1 were utilized as an experimental model to study the cellular responses induced by the virus. Infected monolayers showed increased permeability for [(3)H]mannitol, but no changes were observed for 4-70 kDa dextrans at 48 h post-infection (p.i.), a time at which viral titres reached maximal values and 40 % of the cells expressed viral proteins. A further increase in permeability occurred at 72 h, still without evident cytopathic effects on the monolayer. Coinciding with this, actin was reorganized in the infected cells and the tight junction protein occludin was displaced to the cytoplasm. Increments in the thickness of stress fibres and focal adhesions were observed in uninfected cells neighbouring infected cells. Culture medium from infected monolayers induced permeability changes and thickening of actin-containing structures in control cultures that resembled those observed 48 h p.i. Interleukin (IL) 8 was found in culture medium at concentrations ranging from 20 to 100 pg ml(-1). Neutralizing antibodies against IL8 partially inhibited the changes produced by the culture medium as well as those induced by addition of IL8. Genistein inhibited the effect of the culture medium and the phosphorylation of proteins associated with focal adhesions and indicated the participation of tyrosine kinases. These findings suggest that IL8 production by infected monolayers contributes to the virus-induced effect on the cytoskeleton and tight junctions and thereby modifies transendothelial permeability.

Topics: Cell Line; Cell Membrane Permeability; Culture Media; Cytoskeleton; Dengue; Dengue Virus; Endothelium, Vascular; Humans; Interleukin-8; Microcirculation; Phosphorylation; Recombinant Proteins; Tight Junctions; Viral Proteins

The chemokine interleukin-8 (IL-8) has chemoattractant activity for neutrophils and is able to activate and degranulate these cells. We investigated whether IL-8 may exert these effects in children with dengue virus infection. Circulating levels of IL-8, neutrophilic elastase (a constituent of the azurophilic granula of neutrophils), and lactoferrin, released from specific granula, were measured in 186 children with dengue virus infection, 33 healthy children as negative controls and 11 children with bacterial infections as positive controls. Levels of IL-8 on admission were elevated in 71% of the dengue patients, while the elastase and lactoferrin levels were increased in 68 and 17% of patients, respectively. These levels were significantly higher than in healthy children (P < 0.05) for IL-8 and elastase but not for lactoferrin (by the Wilcoxon-Mann-Whitney [WMW] U test). Similar levels of IL-8 were found in patients with bacterial infections. Levels of IL-8 and elastase in patients with shock were significantly higher than in patients without shock (P = 0.02; WMW), but those of lactoferrin were not. IL-8 correlated with elastase and lactoferrin (r = 0.19 and P = 0.009 versus r = 0.24 and P = 0.001, respectively; two-tailed Spearman rank correlation). Thus, IL-8 levels are increased in most patients with dengue virus infection and correlate with degranulation of neutrophils as well as with some clinical and hemodynamic variables. These findings suggest a role for IL-8 in the pathogenesis of dengue virus infection.

Topics: Cell Degranulation; Child; Dengue; Humans; Inflammation Mediators; Interleukin-8; Lactoferrin; Leukocyte Elastase; Neutrophils; Shock, Septic

Dengue virus causes dengue fever, a mild febrile illness, and at times dengue hemorrhagic fever (DHF), a severe illness the pathogenesis of which is not fully understood. Given the crucial roles played by interleukin-8 (IL-8) as a chemoattractant cytokine and in inflammatory processes, levels of circulating IL-8 in the sera and IL-8 mRNA in the peripheral blood mononuclear cells (PBMC) were measured in 99 patients of a recent dengue epidemic that occurred in India in 1996 and in 21 normal healthy controls. Twenty-six of the patients had dengue fever (DF) and the remaining 73 were diagnosed as having different grades of DHF. All the control normal sera were negative for IL-8, so were their PBMC for IL-8 mRNA. Increased levels of IL-8 in the sera and IL-8 mRNA in their PBMC were observed in patients with severe illness of DHF grades III and IV. Only two out of 26 patients of DF and one out of 10 DHF grade I patient were positive for IL-8 and all three deteriorated to DHF grade IV within 24 hr. All six patients of DHF grade IV who died had higher serum level of IL-8 above 200 pg/ml, the highest being 5,568 pg/ml in one patient; the presence of mRNA for IL-8 was very high in all patients. A striking correlation was observed between increased levels of IL-8 and severe DHF, with greater levels in patients with increased grade of the disease and death. These results suggest that IL-8 may have an important role and may be an indicator of increasing severity of the disease and death.

Topics: Adolescent; Adult; Child; Child, Preschool; Dengue; Female; Gene Expression; Humans; India; Infant; Interleukin-8; Male; Middle Aged; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Viral; Severe Dengue