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1.
Parasitol Res ; 122(12): 2891-2905, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37776335

RESUMO

Cryptosporidium is a major cause of diarrhoeal disease and mortality in young children in resource-poor countries, for which no vaccines or adequate therapeutic options are available. Infection in humans is primarily caused by two species: C. hominis and C. parvum. Despite C. hominis being the dominant species infecting humans in most countries, very little is known about its growth characteristics and life cycle in vitro, given that the majority of our knowledge of the in vitro development of Cryptosporidium has been based on C. parvum. In the present study, the growth and development of two C. parvum isolates (subtypes Iowa-IIaA17G2R1 and IIaA18G3R1) and one C. hominis isolate (subtype IdA15G1) in HCT-8 cells were examined and compared at 24 h and 48 h using morphological data acquired with scanning electron microscopy. Our data indicated no significant differences in the proportion of meronts or merozoites between species or subtypes at either time-point. Sexual development was observed at the 48-h time-point across both species through observations of both microgamonts and macrogamonts, with a higher frequency of macrogamont observations in C. hominis (IdA15G1) cultures at 48-h post-infection compared to both C. parvum subtypes. This corresponded to differences in the proportion of trophozoites observed at the same time point. No differences in proportion of microgamonts were observed between the three subtypes, which were rarely observed across all cultures. In summary, our data indicate that asexual development of C. hominis is similar to that of C. parvum, while sexual development is accelerated in C. hominis. This study provides new insights into differences in the in vitro growth characteristics of C. hominis when compared to C. parvum, which will facilitate our understanding of the sexual development of both species.


Assuntos
Criptosporidiose , Cryptosporidium parvum , Cryptosporidium , Criança , Animais , Humanos , Pré-Escolar , Iowa , Estágios do Ciclo de Vida
2.
J Gen Virol ; 102(10)2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34665110

RESUMO

Viperin has antiviral function against many viruses, including dengue virus (DENV), when studied in cells in culture. Here, the antiviral actions of viperin were defined both in vitro and in a mouse in vivo model of DENV infection. Murine embryonic fibroblasts (MEFs) derived from mice lacking viperin (vip-/-) showed enhanced DENV infection, accompanied by increased IFN-ß and induction of ISGs; IFIT1 and CXCL-10 but not IRF7, when compared to wild-type (WT) MEFs. In contrast, subcutaneous challenge of immunocompetent WT and vip-/- mice with DENV did not result in enhanced infection. Intracranial infection with DENV resulted in body weight loss and neurological disease with a moderate increase in mortality in vip-/- compared with WT mice, although this was not accompanied by altered brain morphology, immune cell infiltration or DENV RNA level in the brain. Similarly, DENV induction of IFN-ß, IFIT1, CXCL-10, IRF7 and TNF-α was not significantly different in WT and vip-/- mouse brain, although there was a modest but significant increase in DENV induction of IL-6 and IfI27la in the absence of viperin. NanoString nCounter analysis confirmed no significant difference in induction of a panel of inflammatory genes in WT compared to vip-/- DENV-infected mouse brains. Further, polyI:C stimulation of bone marrow-derived macrophages (BMDMs) induced TNF-α, IFN-ß, IL-6 and Nos-2, but responses were not different in BMDMs generated from WT or vip-/- mice. Thus, while there is significant evidence of anti-DENV actions of viperin in some cell types in vitro, for DENV infection in vivo a lack of viperin does not affect systemic or brain susceptibility to DENV or induction of innate and inflammatory responses.


Assuntos
Antivirais , Vírus da Dengue/imunologia , Vírus da Dengue/fisiologia , Dengue/imunologia , Dengue/virologia , Imunidade Inata , Proteínas/fisiologia , Animais , Encéfalo/imunologia , Encéfalo/virologia , Células Cultivadas , Inflamação , Fator Regulador 7 de Interferon/genética , Interferon beta/biossíntese , Interferon beta/genética , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Proteínas/genética , Replicação Viral
3.
J Gen Virol ; 102(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33410734

RESUMO

The complement alternative pathway (AP) is tightly regulated and changes in two important AP components, factor B (FB) and factor H (FH) are linked to severe dengue in humans. Here, a mouse model of dengue was investigated to define the changes in FB and FH and assess the utility of this model to study the role of the AP in severe dengue. Throughout the period of viremia in the AG129 IFN signalling-deficient mouse, an increase in FB and a decrease in FH was observed following dengue virus (DENV) infection, with the former only seen in a model of more severe disease associated with antibody-dependent enhancement (ADE). Terminal disease was associated with a decrease in FB and FH, with greater changes during ADE, and accompanied by increased C3 degradation consistent with complement activation. In silico analysis of NFκΒ, signal transducer and activator of transcription (STAT) and IFN-driven FB and FH promoter elements to reflect the likely impact of the lack of IFN-responses in AG129 mice, demonstrated that these elements differed markedly between human and mouse, notably with mouse FH lacking NFκΒ and key IFN-stimulated response elements (ISRE), and FB with many more NFκΒ and STAT-responsive elements than human FB. Thus, the AG129 mouse offers utility in demonstrating changes in FB and FH that, similar to humans, are associated with severe disease, but lack predicted important human-specific and IFN-dependent responses of FB and FH to DENV-infection that are likely to regulate the subtleties of the overall AP response during dengue disease in humans.


Assuntos
Fator B do Complemento/metabolismo , Fator H do Complemento/metabolismo , Via Alternativa do Complemento , Dengue/imunologia , Dengue Grave/imunologia , Animais , Anticorpos Facilitadores , Fator B do Complemento/genética , Fator H do Complemento/genética , Dengue/virologia , Vírus da Dengue/imunologia , Vírus da Dengue/fisiologia , Modelos Animais de Doenças , Humanos , Interferons/metabolismo , Camundongos , Regiões Promotoras Genéticas , Dengue Grave/virologia , Viremia
4.
J Gen Virol ; 101(1): 79-85, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31774391

RESUMO

Dengue virus (DENV) infection is associated with clinical ocular presentations and here DENV infection of the eye was assessed in mice. In an AG129 mouse model of antibody-dependent enhancement of DENV infection, DENV RNA was detected in the eye and vascular changes were present in the retinae. Intraocular CD8 and IFN-γ mRNA were increased in mice born to DENV-naïve, but not DENV-immune mothers, while TNF-α mRNA was induced and significantly higher in mice born to DENV-immune than DENV-naïve mothers. DENV RNA was detected in the eye following intracranial DENV infection and CD8 mRNA but not IFN-γ nor TNF-α were induced. In all models, viperin was increased following DENV infection. Thus, DENV in the circulation or the brain can infect the eye and stimulate innate immune responses, with induction of viperin as one response that consistently occurs in multiple DENV eye-infection models in both an IFN-dependent and independent manner.


Assuntos
Vírus da Dengue/imunologia , Dengue/imunologia , Infecções Oculares Virais/imunologia , Infecções Oculares Virais/virologia , Inflamação/imunologia , Inflamação/virologia , Animais , Anticorpos Facilitadores/imunologia , Dengue/virologia , Modelos Animais de Doenças , Olho/imunologia , Olho/virologia , Imunidade Inata/imunologia , Interferon gama/imunologia , Camundongos , Fator de Necrose Tumoral alfa/imunologia
5.
J Gen Virol ; 100(4): 629-641, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30869582

RESUMO

There is growing evidence of the influence of sphingosine kinase (SK) enzymes on viral infection. Here, the role of sphingosine kinase 2 (SK2), an isoform of SK prominent in the brain, was defined during dengue virus (DENV) infection. Chemical inhibition of SK2 activity using two different SK2 inhibitors, ABC294640 and K145, had no effect on DENV infection in human cells in vitro. In contrast, DENV infection was restricted in SK2-/- immortalized mouse embryonic fibroblasts (iMEFs) with reduced induction of IFN-ß mRNA and protein, and mRNA for the IFN-stimulated genes (ISGs) viperin, IFIT1, IRF7 and CXCL10 in DENV-infected SK2-/- compared to WT iMEFs. Intracranial (ic) DENV injection in C57BL/6 SK2-/- mice induced body weight loss earlier than in WT mice but DENV RNA levels were comparable in the brain. Neither SK1 mRNA or sphingosine-1-phosphate (S1P) levels were altered following ic DENV infection in WT or SK2-/- mice but brain S1P levels were reduced in all SK2-/- mice, independent of DENV infection. CD8 mRNA was induced in the brains of both DENV-infected WT and SK2-/- mice, suggesting normal CD8+ T-cell infiltration into the DENV-infected brain independent of SK2 or S1P. Thus, although SK2 may be important for replication of some viruses SK2 activity does not affect DENV infection in vitro and SK2 or S1P levels do not influence DENV infection or T-cell infiltration in the context of infection in the brain.


Assuntos
Vírus da Dengue/patogenicidade , Dengue/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Adamantano/análogos & derivados , Adamantano/farmacologia , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Linhagem Celular , Linhagem Celular Tumoral , Dengue/tratamento farmacológico , Vírus da Dengue/efeitos dos fármacos , Células HEK293 , Células Hep G2 , Humanos , Interferon beta/metabolismo , Lisofosfolipídeos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Piridinas/farmacologia , RNA Mensageiro/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Tiazolidinedionas/farmacologia
6.
J Virol ; 92(14)2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29743365

RESUMO

Severe dengue virus (DENV) infection is associated with overactivity of the complement alternative pathway (AP) in patient studies. Here, the molecular changes in components of the AP during DENV infection in vitro were investigated. mRNA for factor H (FH), a major negative regulator of the AP, was significantly increased in DENV-infected endothelial cells (EC) and macrophages, but, in contrast, production of extracellular FH protein was not. This discord was not seen for the AP activator factor B (FB), with DENV induction of both FB mRNA and protein, nor was it seen with Toll-like receptor 3 or 4 stimulation of EC and macrophages, which induces both FH and FB mRNA and protein. Surface-bound and intracellular FH protein was, however, induced by DENV, but only in DENV antigen-positive cells, while in two other DENV-susceptible immortalized cell lines (ARPE-19 and human retinal endothelial cells), FH protein was induced both intracellularly and extracellularly by DENV infection. Regardless of the cell type, there was an imbalance in AP components and an increase in markers of complement AP activity associated with DENV-infected cells, with lower FH relative to FB protein, an increased ability to promote AP-mediated lytic activity, and increased deposition of complement component C3b on the surface of DENV-infected cells. For EC in particular, these changes are predicted to result in higher complement activity in the local cellular microenvironment, with the potential to induce functional changes that may result in increased vascular permeability, a hallmark of dengue disease.IMPORTANCE Dengue virus (DENV) is a significant human viral pathogen with a global medical and economic impact. DENV may cause serious and life-threatening disease, with increased vascular permeability and plasma leakage. The pathogenic mechanisms underlying these features remain unclear; however, overactivity of the complement alternative pathway has been suggested to play a role. In this study, we investigate the molecular events that may be responsible for this observed alternative pathway overactivity and provide novel findings of changes in the complement system in response to DENV infection in primary cell types that are a major target for DENV infection (macrophages) and pathogenesis (endothelial cells) in vivo Our results suggest a new dimension of cellular events that may influence endothelial cell barrier function during DENV infection that could expand strategies for developing therapeutics to prevent or control DENV-mediated vascular disease.


Assuntos
Fator B do Complemento/imunologia , Fator H do Complemento/imunologia , Via Alternativa do Complemento , Proteínas do Sistema Complemento/imunologia , Vírus da Dengue/imunologia , Dengue/imunologia , Células Cultivadas , Fator B do Complemento/metabolismo , Fator H do Complemento/metabolismo , Proteínas do Sistema Complemento/metabolismo , Dengue/metabolismo , Dengue/virologia , Endotélio Vascular/imunologia , Endotélio Vascular/patologia , Endotélio Vascular/virologia , Humanos , Retina/imunologia , Retina/patologia , Retina/virologia
8.
Clin Exp Ophthalmol ; 47(3): 372-380, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30474222

RESUMO

Recently recognized forms of uveitis include intraocular inflammations that occur during or following one of several emerging infectious diseases: chikungunya fever, dengue, Zika virus disease and Ebola virus disease. Anterior, intermediate, posterior and pan-uveitis have been described in individuals infected with chikungunya virus. Persons who contract dengue or Zika viruses also may develop different types of uveitis in the course of the infection: maculopathy is a common manifestation of dengue eye disease, and Zika eye disease may cause hypertensive anterior uveitis or mimic a white dot syndrome. Up to one-third of Ebola survivors develop aggressive uveitis, which is frequently associated with vision loss and complicated by cataract. There are no specific anti-viral drugs for these forms of uveitis, and thus treatment is largely supportive. In this article, we summarize the systemic infectious diseases and virology, and describe the clinical presentations, outcomes and management of emerging viral forms of uveitis.


Assuntos
Febre de Chikungunya/virologia , Doenças Transmissíveis Emergentes/virologia , Dengue/virologia , Infecções Oculares Virais/virologia , Doença pelo Vírus Ebola/virologia , Uveíte/virologia , Infecção por Zika virus/virologia , Febre de Chikungunya/diagnóstico , Doenças Transmissíveis Emergentes/diagnóstico , Dengue/diagnóstico , Infecções Oculares Virais/diagnóstico , Doença pelo Vírus Ebola/diagnóstico , Humanos , Uveíte/diagnóstico , Infecção por Zika virus/diagnóstico
10.
Health Econ ; 26(4): 403-420, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-26918400

RESUMO

In 2011, the USA had the second highest teen birth rate of any developed nation, according to the World Bank, . In an effort to lower teen pregnancy rates, several states have enacted policies requiring abstinence-based sex education. In this study, we utilize a difference-in-differences research design to analyze the causal effects of state-level sex education policies from 2000-2011 on various teen sexual health outcomes. We find that state-level abstinence education mandates have no effect on teen birth rates or abortion rates, although we find that state-level policies may affect teen sexually transmitted disease rates in some states. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Saúde do Adolescente/estatística & dados numéricos , Coeficiente de Natalidade , Política de Saúde , Gravidez na Adolescência/prevenção & controle , Educação Sexual/métodos , Abstinência Sexual/estatística & dados numéricos , Adolescente , Feminino , Humanos , Masculino , Gravidez , Comportamento Sexual , Infecções Sexualmente Transmissíveis/prevenção & controle , Estados Unidos
11.
Mediators Inflamm ; 2017: 3164375, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29515292

RESUMO

Recent clinical reports indicate that infection with dengue virus (DENV) commonly has ocular manifestations. The most serious threat to vision is dengue retinopathy, including retinal vasculopathy and macular edema. Mechanisms of retinopathy are unstudied, but observations in patients implicate retinal pigment epithelial cells and retinal endothelial cells. Human retinal cells were inoculated with DENV-2 and monitored for up to 72 hours. Epithelial and endothelial cells supported DENV replication and release, but epithelial cells alone demonstrated clear cytopathic effect, and infection was more productive in those cells. Infection induced type I interferon responses from both cells, but this was stronger in epithelial cells. Endothelial cells increased expression of adhesion molecules, with sustained overexpression of vascular adhesion molecule-1. Transcellular impedance decreased for epithelial monolayers, but not endothelial monolayers, coinciding with cytopathic effect. This reduction was accompanied by disorganization of intracellular filamentous-actin and decreased expression of junctional molecules, zonula occludens 1, and catenin-ß1. Changes in endothelial expression of adhesion molecules are consistent with the retinal vasculopathy seen in patients infected with DENV; decreases in epithelial junctional protein expression, paralleling loss of integrity of the epithelium, provide a molecular basis for DENV-associated macular edema. These molecular processes present potential therapeutic targets for vision-threatening dengue retinopathy.


Assuntos
Vírus da Dengue/patogenicidade , Células Endoteliais/virologia , Retina/citologia , Linhagem Celular , Células Cultivadas , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Humanos , Imuno-Histoquímica , Junções Íntimas/imunologia , Junções Íntimas/virologia , Replicação Viral/fisiologia
12.
J Gen Virol ; 97(1): 95-109, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26541871

RESUMO

Sphingosine kinase (SK) 1 is a host kinase that enhances some viral infections. Here we investigated the ability of SK1 to modulate dengue virus (DENV) infection in vitro. Overexpression of SK1 did not alter DENV infection; however, targeting SK1 through chemical inhibition resulted in reduced DENV RNA and infectious virus release. DENV infection of SK1⁻/ ⁻ murine embryonic fibroblasts (MEFs) resulted in inhibition of infection in an immortalized line (iMEF) but enhanced infection in primary MEFs (1°MEFs). Global cellular gene expression profiles showed expected innate immune mRNA changes in DENV-infected WT but no induction of these responses in SK1⁻/⁻ iMEFs. Reverse transciption PCR demonstrated a low-level induction of IFN-ß and poor induction of mRNA for the interferon-stimulated genes (ISGs) viperin, IFIT1 and CXCL10 in DENV-infected SK1⁻/⁻ compared with WT iMEFs. Similarly, reduced induction of ISGs was observed in SK1⁻/⁻ 1°MEFs, even in the face of high-level DENV replication. In both iMEFs and 1°MEFs, DENV infection induced production of IFN-ß protein. Additionally, higher basal levels of antiviral factors (IRF7, CXCL10 and OAS1) were observed in uninfected SK1⁻/⁻ iMEFs but not 1°MEFs. This suggests that, in this single iMEF line, lack of SK1 upregulates the basal levels of factors that may protect cells against DENV infection. More importantly, regardless of the levels of DENV replication, all cells that lacked SK1 produced IFN-ß but were refractory to induction of ISGs such as viperin, IFIT1 and CXCL10. Based on these findings, we propose new roles for SK1 in affecting innate responses that regulate susceptibility to DENV infection.


Assuntos
Vírus da Dengue/imunologia , Vírus da Dengue/fisiologia , Suscetibilidade a Doenças , Interações Hospedeiro-Patógeno , Imunidade Inata , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Animais , Células Cultivadas , Fibroblastos/virologia , Perfilação da Expressão Gênica , Camundongos Endogâmicos C57BL , Camundongos Knockout
13.
J Med Virol ; 88(10): 1703-10, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26990973

RESUMO

Dengue virus (DENV) infections are increasing with respect to incidence and severity in the Central Province of Sri Lanka. The objective of this study was to define the clinical, immunological, and virological profiles of patients admitted to the General Hospital, Kandy with clinically apparent dengue. Demographic, clinical, hematological parameters, liver enzymes (ALT and AST), and blood samples were collected from 292 patients with fever <5 days post onset and fulfilling the WHO criteria for the diagnosis of dengue fever/dengue hemorrhagic fever (DF/DHF). Samples were analyzed for, anti-DENV IgM, IgG, and DENV nucleic acid. Myalgia was the commonest complaint by 65% of the patients. Packed cell volume was >45% in 27% of the patients while 42.12% had reduced platelets and 62.67% had reduced white blood cell counts. In contrast to other studies, positive tourniquet test (PTT) and petechiae were not major indicators of DENV infection or severity of the disease. Clinical profiles were significantly different between DF and DHF/DSS and showed many similarities to that reported elsewhere. Altogether, 43 patients (14.73%) were viremic as detected by RT-PCR; 181 patients (62%) were positive for anti-DENV IgM, and 245 (84%) patients were positive for anti-DENV IgG. In combination, anti-DENV IgM and RT-PCR assays detected 224 (77.5%) of DENV infected cases, thus improving the DENV diagnosis rate. Hence, the diagnostic utility of PTT, anti-DENV IgM/IgG serology, or RT-PCR used alone in the early phase of illness is low in Sri Lanka but the diagnostic value can be improved by a combination of serology and RT-PCR. J. Med. Virol. 88:1703-1710, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Dengue/diagnóstico , Dengue/imunologia , Dengue Grave/diagnóstico , Dengue Grave/imunologia , Adulto , Anticorpos Antivirais/sangue , Demografia , Dengue/fisiopatologia , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/imunologia , Doenças Endêmicas/prevenção & controle , Doenças Endêmicas/estatística & dados numéricos , Ensaio de Imunoadsorção Enzimática , Feminino , Febre , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Incidência , Masculino , Mialgia/virologia , Púrpura , RNA Viral/sangue , Reação em Cadeia da Polimerase em Tempo Real , Dengue Grave/fisiopatologia , Dengue Grave/virologia , Sri Lanka/epidemiologia , Adulto Jovem
14.
Cytokine ; 83: 182-188, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27155816

RESUMO

The objective of the present study was to assess the circulating TNF-α and IL-2 levels in dengue virus (DENV) infected patients and to correlate these with clinical severity of DENV infections. A single analyte quantitative immunoassay was used to detect TNF-α and IL-2 in 24 dengue fever (DF) and 43 dengue haemorrhagic fever (DHF) patients, 15 healthy adults and 6 typhoid patients. The mean TNF-α and IL-2 levels of DENV- infected patients were higher than that of healthy adults and typhoid patients. No significant difference in TNF-α levels was noted between DF and DHF patients (p=0.5) but a significant increase in IL-2 levels was observed in DHF compared with DF patients (mean of DF=59.7pg/mL, mean of DHF=166.9pg/mL; p=0.02). No significant association of TNF-α or IL-2 levels was noted with packed cell volume (>45), thrombocytopenia, leucopenia or the presence of viraemia. The liver function tests measuring AST (aspartate aminotransferase) (p=0.01) and ALT (alanine aminotransferase) (p=0.02) levels were significantly elevated in DENV-infected patients. AST:ALT was significantly elevated in DHF/DSS (dengue shock syndrome) compared with DF patients. A significant positive linear correlation was noted between AST and IL-2 (r=0.31; p=0.01) and ALT and IL-2 elevations (r=0.2; p=0.02). Thus, AST and ALT levels correlate with both disease severity and circulating IL-2 levels. We suggest a role for circulating IL-2 in liver dysfunction and propose that a combined assessment of AST/ALT in conjunction with IL-2 at the early stages of symptomatic DENV infection may be useful to predict the severe forms of dengue.


Assuntos
Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Vírus da Dengue , Dengue/sangue , Interleucina-2/sangue , Fígado/enzimologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Estudos Prospectivos , Índice de Gravidade de Doença , Fator de Necrose Tumoral alfa/sangue
15.
Mediators Inflamm ; 2015: 509306, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26609198

RESUMO

One of the main pathogenic effects of severe dengue virus (DENV) infection is a vascular leak syndrome. There are no available antivirals or specific DENV treatments and without hospital support severe DENV infection can be life-threatening. The cause of the vascular leakage is permeability changes in the endothelial cells lining the vasculature that are brought about by elevated vasoactive cytokine and chemokines induced following DENV infection. The source of these altered cytokine and chemokines is traditionally believed to be from DENV-infected cells such as monocyte/macrophages and dendritic cells. Herein we discuss the evidence for the endothelium as an additional contributor to inflammatory and innate responses during DENV infection which may affect endothelial cell function, in particular the ability to maintain vascular integrity. Furthermore, we hypothesise roles for two factors, sphingosine kinase-1 and microRNAs (miRNAs), with a focus on several candidate miRNAs, which are known to control normal vascular function and inflammatory responses. Both of these factors may be potential therapeutic targets to regulate inflammation of the endothelium during DENV infection.


Assuntos
Dengue/fisiopatologia , Endotélio Vascular/patologia , Inflamação/etiologia , MicroRNAs/fisiologia , Fosfotransferases (Aceptor do Grupo Álcool)/fisiologia , Permeabilidade Capilar , Humanos
16.
Rev Med Virol ; 23(2): 73-84, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22639116

RESUMO

Sphingosine kinase 1 (SphK1) is an enzyme that phosphorylates the lipid sphingosine to generate sphingosine-1-phosphate (S1P). S1P can act intracellularly as a signaling molecule and extracellularly as a receptor ligand. The SphK1/S1P axis has well-described roles in cell signaling, the cell death/survival decision, the production of a pro-inflammatory response, immunomodulation, and control of vascular integrity. Agents targeting the SphK1/S1P axis are being actively developed as therapeutics for cancer and immunological and inflammatory disorders. Control of cell death/survival and pro-inflammatory immune responses is central to the pathology of infectious disease, and we can capitalize on the knowledge provided by investigations of SphK1/S1P in cancer and immunology to assess its application to selected human infections. We have herein reviewed the growing literature relating viral infections to changes in SphK1 and S1P. SphK1 activity is reportedly increased following human cytomegalovirus and respiratory syncytial virus infections, and elevated SphK1 enhances influenza virus infection. In contrast, SphK1 activity is reduced in bovine viral diarrhea virus and dengue virus infections. Sphingosine analogs that modulate S1P receptors have proven useful in animal models in alleviating influenza virus infection but have shown no benefit in simian human immunodeficiency virus and lymphocytic choriomeningitis virus infections. We have rationalized a role for SphK1/S1P in dengue virus, chikungunya virus, and Ross River virus infections, on the basis of the biology and the pathology of these diseases. The increasing number of effective SphK1 and S1P modulating agents currently in development makes it timely to investigate these roles with the potential for developing modulators of SphK1 and S1P for novel anti-viral therapies.


Assuntos
Lisofosfolipídeos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Transdução de Sinais , Esfingosina/análogos & derivados , Viroses/imunologia , Animais , Modelos Animais de Doenças , Humanos , Fatores Imunológicos/metabolismo , Esfingosina/metabolismo , Viroses/patologia
17.
Microbiol Spectr ; 12(1): e0239123, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38054722

RESUMO

IMPORTANCE: Dengue disease is characterized by an inflammatory-mediated immunopathology, with elevated levels of circulating factors including TNF-α and IL-6. If the damaging inflammatory pathways could be blocked without loss of antiviral responses or exacerbating viral replication, then this would be of potential therapeutic benefit. The study here has investigated the Vav guanine exchange factors as a potential alternative signaling pathway that may drive dengue virus (DENV)-induced inflammatory responses, with a focus on Vav1 and 2. While Vav proteins were positively associated with mRNA for inflammatory cytokines, blocking Vav signaling didn't affect DENV replication but prevented DENV-induction of p-ERK and enhanced IL-6 (inflammatory) and viperin (antiviral) mRNA. These initial data suggest that Vav proteins could be a target that does not compromise control of viral replication and should be investigated further for broader impact on host inflammatory responses, in settings such as antibody-dependent enhancement of infection and in different cell types.


Assuntos
Vírus da Dengue , Dengue , Humanos , Vírus da Dengue/genética , Interleucina-6 , RNA Mensageiro , Replicação Viral , Antivirais
18.
Viruses ; 16(8)2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39205304

RESUMO

Zika virus (ZIKV) impacts the developing brain. Here, a technique was applied to define, in 3D, developmental changes in the brains of ZIKV-infected mice. Postnatal day 1 mice were uninfected or ZIKV-infected, then analysed by iodine staining and micro-CT scanning (diffusible iodine contrast-enhanced micro-CT; diceCT) at 3-, 6-, and 10-days post-infection (dpi). Multiple brain regions were visualised using diceCT: the olfactory bulb, cerebrum, hippocampus, midbrain, interbrain, and cerebellum, along with the lens and retina of the eye. Brain regions were computationally segmented and quantitated, with increased brain volumes and developmental time in uninfected mice. Conversely, in ZIKV-infected mice, no quantitative differences were seen at 3 or 6 dpi when there were no clinical signs, but qualitatively, diverse visual defects were identified at 6-10 dpi. By 10 dpi, ZIKV-infected mice had significantly lower body weight and reduced volume of brain regions compared to 10 dpi-uninfected or 6 dpi ZIKV-infected mice. Nissl and immunofluorescent Iba1 staining on post-diceCT tissue were successful, but RNA extraction was not. Thus, diceCT shows utility for detecting both 3D qualitative and quantitative changes in the developing brain of ZIKV-infected mice, with the benefit, post-diceCT, of retaining the ability to apply traditional histology and immunofluorescent analysis to tissue.


Assuntos
Encéfalo , Modelos Animais de Doenças , Infecção por Zika virus , Zika virus , Animais , Infecção por Zika virus/virologia , Infecção por Zika virus/patologia , Encéfalo/virologia , Encéfalo/patologia , Encéfalo/diagnóstico por imagem , Camundongos , Zika virus/fisiologia , Microtomografia por Raio-X , Feminino
19.
Access Microbiol ; 6(9)2024.
Artigo em Inglês | MEDLINE | ID: mdl-39346684

RESUMO

The rat is a useful laboratory model for respiratory diseases. SARS-CoV-2 proteins, such as the spike (S) protein, can induce inflammation. This study has investigated the ability of the Q498Y, P499T (QP-YT) amino acid change, described in the S-protein of the mouse-adapted laboratory SARS-CoV-2 MA strain, to interact with rat angiotensin converting enzyme-2 (ACE2) and stimulate responses in rat lungs. A real-time S-ACE2 quantitative fusion assay shows that ancestral and L452R S-proteins fuse with human but not rat ACE2 expressed on HEK293 (human embryonic kidney-293) cells. The QP-YT S-protein retains the ability to fuse with human ACE2 and increases the binding to rat ACE2. Although lower lung of the rat contains both ACE2 and TMPRSS2 (transmembrane serine protease 2) target cells, intratracheal delivery of ancestral or QP-YT S-protein pseudotyped lentivirus did not induce measurable respiratory changes, inflammatory infiltration or innate mRNA responses. Isolation of primary cells from rat alveoli demonstrated the presence of cells expressing ACE2 and TMPRSS2. Infection of these cells, however, with ancestral or QP-YT S-protein pseudotyped lentivirus was not observed, and the QP-YT S-protein pseudotyped lentivirus poorly infected HEK293 cells expressing rat ACE2. Analysis of the amino acid changes across the S-ACE2 interface highlights not only the Y498 interaction with H353 as a likely facilitator of binding to rat ACE2 but also other amino acids that could improve this interaction. Thus, rat lungs contain cells expressing receptors for SARS-CoV-2, and the QP-YT S-protein variant can bind to rat ACE2, but this does not result in infection or stimulate responses in the lung. Further, amino acid changes in S-protein may enhance this interaction to improve the utility of the rat model for defining the role of the S-protein in driving lung inflammation.

20.
PLoS One ; 18(11): e0293737, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37910583

RESUMO

The long-term protection and restoration of aquatic resources depends on robust monitoring data; data that require systematic quality control and analysis tools. The MassWateR R package facilitates quality control, analysis, and data sharing for discrete surface water quality data collected by monitoring programs of various size and technical capacity. The tools were developed to address regional needs for programs in Massachusetts, USA, but the principles and outputs can be applicable to monitoring data collected anywhere. Users can create quality control reports, perform outlier analyses, and assess trends by season, date, and site for more than 40 parameters. Users can also prepare data for submission to the United States Environmental Protection Agency Water Quality Exchange, thus sharing data to the largest water quality database in the United States. The automated and reproducible workflow offered by MassWateR is expected to increase the quantity and quality of publicly available data to support the management of aquatic resources.


Assuntos
Monitoramento Ambiental , Qualidade da Água , Estados Unidos , Bases de Dados Factuais , Confiabilidade dos Dados , Controle de Qualidade
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