Medicine and Health Sciences Commons^™

Viral Replication And Paracrine Effects Result In Distinct, Functional Responses Of Dendritic Cells Following Infection With Dengue 2 Virus, Zachary Nightingale, Chinmay Patkar, Alan Rothman

Alan Rothman

Dengue virus (DENV), a re-emerging arbovirus, readily infects dendritic cells (DC) in culture and in vivo. However, there have been contradictory reports regarding the effect of DENV infection on DC activation and maturation. DC undergo a series of functional changes following exposure to infectious agents, including cytokine production and costimulatory and MHC molecule induction, culminating in stimulation of adaptive immune responses. Immunological memory to primary DENV infection critically influences disease severity during subsequent infections with heterologous serotypes. To explore these phenomena, we examined DENV infection-dependent and -independent effects on DC secretory, phenotypic, and allostimulatory functions. DENV infection of DC resulted …

Impaired T Cell Proliferation In Acute Dengue Infection, Anuja Mathew, Ichiro Kurane, Sharone Green, David Vaughn, Siripen Kalayanarooj, Saroj Suntayakorn, Francis Ennis, Alan Rothman

Alan Rothman

Decreased proliferative responses to mitogens and recall Ags have been observed in PBMC obtained during several acute human viral infections. To determine whether cell-mediated responses are altered during acute dengue infection, we examined the proliferative responses of PBMC from children enrolled in a prospective study of dengue infections in Thailand. All responses of PBMC during acute illness were compared with the same patients' PBMC obtained at least 6 mo after their infection. Proliferative responses to PHA, anti-CD3, tetanus toxoid, and dengue Ags were decreased significantly in PBMC obtained during the acute infection. The proliferative responses to PHA were restored by …

Intracellular Cytokine Production By Dengue Virus-Specific T Cells Correlates With Subclinical Secondary Infection, Steven Hatch, Timothy Endy, Stephen Thomas, Anuja Mathew, James Potts, Pamela Pazoles, Daniel Libraty, Robert Gibbons, Alan Rothman

Alan Rothman

The pathophysiology of dengue virus infection remains poorly understood, although secondary infection is strongly associated with more severe disease. In the present study, we performed a nested, case-control study comparing the responses of pre-illness peripheral blood mononuclear cells between children who would subsequently develop either subclinical or symptomatic secondary infection 6-11 months after the baseline blood samples were obtained and frozen. We analyzed intracellular cytokine production by CD4(+) and CD8(+) cells in response to stimulation with dengue antigen. We found higher frequencies of dengue virus-specific TNFalpha, IFNgamma-, and IL-2-producing T cells among schoolchildren who subsequently developed subclinical infection, compared with …

T Cell Responses To An Hla-B*07-Restricted Epitope On The Dengue Ns3 Protein Correlate With Disease Severity, Iva Zivna, Sharone Green, David Vaughn, Siripen Kalayanarooj, Henry Stephens, Dasnayanee Chandanayingyong, Ananda Nisalak, Francis Ennis, Alan Rothman

Alan Rothman

Dengue hemorrhagic fever (DHF), the severe manifestation of dengue virus (DV) infection characterized by plasma leakage, is more common in secondary DV infections in previously infected individuals and is associated with high levels of immune activation. To determine the Ag specificity of this immune response, we studied the response to an HLA-B*07-restricted T cell epitope, residues 221-232 of the DV NS3 protein, in 10 HLA-B*07(+) Thai children who were studied during and after acute DV infections. Peptide-specific T cells were detected in 9 of 10 subjects. The frequency of peptide-specific T cells was higher in subjects who had experienced DHF …

Dengue: Defining Protective Versus Pathologic Immunity, Alan Rothman

Alan Rothman

Dengue is an expanding public health problem, and an effective vaccine remains elusive. This review discusses how the significant influence of sequential infection with different dengue virus serotypes on the severity of disease can be viewed in terms of beneficial and detrimental effects of heterologous immunity. A more complete understanding of these effects is likely to be critical for predicting optimal vaccine-induced immune responses.

Determinants Of Inapparent And Symptomatic Dengue Infection In A Prospective Study Of Primary School Children In Kamphaeng Phet, Thailand, Timothy Endy, Kathryn Anderson, Ananda Nisalak, In-Kyu Yoon, Sharone Green, Alan Rothman, Stephen Thomas, Richard Jarman, Daniel Libraty, Robert Gibbons

Alan Rothman

BACKGROUND: Dengue viruses are a major cause of morbidity in tropical and subtropical regions of the world. Inapparent dengue is an important component of the overall burden of dengue infection. It provides a source of infection for mosquito transmission during the course of an epidemic, yet by definition is undetected by health care providers. Previous studies of inapparent or subclinical infection have reported varying ratios of symptomatic to inapparent dengue infection.

METHODOLOGY/PRINCIPAL FINDINGS: In a prospective study of school children in Northern Thailand, we describe the spatial and temporal variation of the symptomatic to inapparent (S:I) dengue illness ratio. Our …

T Cell Receptor Vbeta Gene Usage In Thai Children With Dengue Virus Infection, Susan Gagnon, Anita Leporati, Sharone Green, Siripen Kalayanarooj, David Vaughn, Henry Stephens, Saroj Suntayakorn, Ichiro Kurane, Francis Ennis, Alan Rothman

Alan Rothman

T lymphocyte activation during dengue is thought to contribute to the pathogenesis of dengue hemorrhagic fever (DHF). We examined the T cell receptor Vbeta gene usage by a reverse transcriptase-polymerase chain reaction assay during infection and after recovery in 13 children with DHF and 13 children with dengue fever (DF). There was no deletion of specific Vbeta gene families. We detected significant expansions in usage of single Vbeta families in six subjects with DHF and three subjects with DF over the course of infection, but these did not show an association with clinical diagnosis, viral serotype, or HLA alleles. Differences …

Clinical And Laboratory Features That Distinguish Dengue From Other Febrile Illnesses In Endemic Populations, James Potts, Alan Rothman

Alan Rothman

OBJECTIVE: Clinicians in resource-poor countries need to identify patients with dengue using readily-available data. The objective of this systematic review was to identify clinical and laboratory features that differentiate dengue fever (DF) and/or dengue haemorrhagic fever (DHF) from other febrile illnesses (OFI) in dengue-endemic populations. METHOD: Systematic review of the literature from 1990 to 30 October 2007 including English publications comparing dengue and OFI. RESULTS: Among 49 studies reviewed, 34 did not meet our criteria for inclusion. Of the 15 studies included, 10 were prospective cohort studies and five were case-control studies. Seven studies assessed all ages, four assessed children …

Virus-Induced Decline In Soluble Vascular Endothelial Growth Receptor 2 Is Associated With Plasma Leakage In Dengue Hemorrhagic Fever, Anon Srikiatkhachorn, Chuanpis Ajariyakhajorn, Timothy Endy, Siripen Kalayanarooj, Daniel Libraty, Sharone Green, Francis Ennis, Alan Rothman

Alan Rothman

Some individuals infected with dengue virus develop dengue hemorrhagic fever (DHF), a viral hemorrhagic disease characterized by a transient period of localized plasma leakage. To determine the importance of vascular endothelial growth factor A (VEGF-A) in this syndrome, we compared plasma levels of VEGF-A and the soluble forms of its receptors in patients with DHF to patients with dengue fever (DF), a milder form of dengue virus infection without plasma leakage. We observed a rise in the plasma levels of free, but not total VEGF-A in DHF patients at the time of plasma leakage. This was associated with a decline …

Cell Type-Specific Mechanisms Of Interleukin-8 Induction By Dengue Virus And Differential Response To Drug Treatment, Carey Medin, Alan Rothman

Alan Rothman

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 …

Classification Of Dengue Illness Based On Readily Available Laboratory Data, James Potts, Stephen Thomas, Anon Srikiatkhachorn, Pra-On Supradish, Wenjun Li, Ananda Nisalak, Suchitra Nimmannitya, Timothy Endy, Daniel Libraty, Robert Gibbons, Sharone Green, Alan Rothman, Siripen Kalayanarooj

Alan Rothman

The aim of this study was to examine retrospective dengue-illness classification using only clinical laboratory data, without relying on X-ray, ultrasound, or percent hemoconcentration. We analyzed data from a study of children who presented with acute febrile illness to two hospitals in Thailand. Multivariable logistic regression models were used to distinguish: (1) dengue hemorrhagic fever (DHF) versus dengue fever (DF), (2) DHF versus DF + other febrile illness (OFI), (3) dengue versus OFI, and (4) severe dengue versus non-severe dengue + OFI. Data from the second hospital served as a validation set. There were 1,227 patients in the analysis. The …

Dengue Virus Induces Novel Changes In Gene Expression Of Human Umbilical Vein Endothelial Cells, Rajas Warke, Kris Xhaja, Katherine Martin, Marcia Fournier, Sunil Shaw, Nathaly Brizuela, Norma De Bosch, David Lapointe, Francis Ennis, Alan Rothman, Irene Bosch

Alan Rothman

Endothelial cells are permissive to dengue virus (DV) infection in vitro, although their importance as targets of DV infection in vivo remains a subject of debate. To analyze the virus-host interaction, we studied the effect of DV infection on gene expression in human umbilical vein endothelial cells (HUVECs) by using differential display reverse transcription-PCR (DD-RTPCR), quantitative RT-PCR, and Affymetrix oligonucleotide microarrays. DD identified eight differentially expressed cDNAs, including inhibitor of apoptosis-1, 2'-5' oligoadenylate synthetase (OAS), a 2'-5' OAS-like (OASL) gene, galectin-9, myxovirus protein A (MxA), regulator of G-protein signaling, endothelial and smooth muscle cell-derived neuropilin-like protein, and phospholipid scramblase 1. …

Predominance Of Hla-Restricted Cytotoxic T-Lymphocyte Responses To Serotype-Cross-Reactive Epitopes On Nonstructural Proteins Following Natural Secondary Dengue Virus Infection, Anuja Mathew, Ichiro Kurane, Sharone Green, Henry Stephens, David Vaughn, Siripen Kalayanarooj, Saroj Suntayakorn, Dasnayanee Chandanayingyong, Francis Ennis, Alan Rothman

Alan Rothman

We examined the memory cytotoxic T-lymphocytic (CTL) responses of peripheral blood mononuclear cells (PBMC) obtained from patients in Thailand 12 months after natural symptomatic secondary dengue virus infection. In all four patients analyzed, CTLs were detected in bulk culture PBMC against nonstructural dengue virus proteins. Numerous CD4+ and CD8+ CTL lines were generated from the bulk cultures of two patients, KPP94-037 and KPP94-024, which were specific for NS1.2a (NS1 and NS2a collectively) and NS3 proteins, respectively. All CTL lines derived from both patients were cross-reactive with other serotypes of dengue virus. The CD8+ NS1.2a-specific lines from patient KPP94-037 were HLA …

B-Cell Responses During Primary And Secondary Dengue Virus Infections In Humans, Anuja Mathew, Kim West, Siripen Kalayanarooj, Robert Gibbons, Anon Srikiatkhachorn, Sharone Green, Daniel Libraty, Smita Jaiswal, Alan Rothman

Alan Rothman

Low-avidity serotype-cross-reactive antibodies are hypothesized to play a key role in triggering severe disease in patients with secondary dengue virus (DENV) infection. However, there is little systematic information about the frequency, avidity, and cross-reactivity of DENV-specific B cells in individuals experiencing primary instead of secondary infection. We compared DENV-specific B-cell responses in a cohort of Thai children with primary or secondary DENV infection. B cells specific for DENV precursor membrane protein, envelope (E) protein, and nonstructural protein 1 were detectable in immune peripheral blood mononuclear cells with the highest frequencies of DENV E-specific B cells detected in patients experiencing primary …

Immunopathologic Mechanisms Of Dengue Hemorrhagic Fever And Dengue Shock Syndrome, Ichiro Kurane, Alan Rothman, Peter Livingston, Sharone Green, Susan Gagnon, Jurand Janus, Bruce Innis, Suchitra Nimmannitya, Ananda Nisalak, Francis Ennis

Alan Rothman

Dengue virus infections are a major cause of morbidity and mortality in tropical and subtropical areas of the world. The immunopathological mechanisms that result in severe complications of dengue virus infection, i.e. dengue hemorrhagic fever (DHF), are important to determine. Primary dengue virus infections induce serotype-specific and serotype-cross-reactive, CD4+ and CD8+ memory cytotoxic T lymphocytes (CTL). In secondary infections with a virus of a different serotype from that which caused primary infections, the presence of cross-reactive non-neutralizing antibodies results in an increased number of infected monocytes by dengue virus--antibody complexes. This in turn results in marked activation of serotype cross-reactive …

Elevated Levels Of Soluble St2 Protein In Dengue Virus Infected Patients, Aniuska Becerra, Rajas Warke, Norma De Bosch, Alan Rothman, Irene Bosch

Alan Rothman

Levels of the soluble form of the interleukin-1 receptor-like 1 protein (IL-1RL-1/ST2) are elevated in the serum of patients with diseases characterized by an inflammatory response. The objective of this study was to determine the concentration of soluble ST2 (sST2) in dengue infected patients during the course of the disease. Twenty-four patients with confirmed dengue infection, classified as dengue fever, and 11 patients with other febrile illness (OFI) were evaluated. Levels of sST2 in serum and laboratory variables usually altered during dengue infections were measured. Dengue infected patients had higher serum sST2 levels than OFI at the end of the …

Impaired T Cell Proliferation In Acute Dengue Infection, Anuja Mathew, Ichiro Kurane, Sharone Green, David Vaughn, Siripen Kalayanarooj, Saroj Suntayakorn, Francis Ennis, Alan Rothman

Sharone Green

Decreased proliferative responses to mitogens and recall Ags have been observed in PBMC obtained during several acute human viral infections. To determine whether cell-mediated responses are altered during acute dengue infection, we examined the proliferative responses of PBMC from children enrolled in a prospective study of dengue infections in Thailand. All responses of PBMC during acute illness were compared with the same patients' PBMC obtained at least 6 mo after their infection. Proliferative responses to PHA, anti-CD3, tetanus toxoid, and dengue Ags were decreased significantly in PBMC obtained during the acute infection. The proliferative responses to PHA were restored by …

T Cell Responses To An Hla-B*07-Restricted Epitope On The Dengue Ns3 Protein Correlate With Disease Severity, Iva Zivna, Sharone Green, David Vaughn, Siripen Kalayanarooj, Henry Stephens, Dasnayanee Chandanayingyong, Ananda Nisalak, Francis Ennis, Alan Rothman

Sharone Green

Dengue hemorrhagic fever (DHF), the severe manifestation of dengue virus (DV) infection characterized by plasma leakage, is more common in secondary DV infections in previously infected individuals and is associated with high levels of immune activation. To determine the Ag specificity of this immune response, we studied the response to an HLA-B*07-restricted T cell epitope, residues 221-232 of the DV NS3 protein, in 10 HLA-B*07(+) Thai children who were studied during and after acute DV infections. Peptide-specific T cells were detected in 9 of 10 subjects. The frequency of peptide-specific T cells was higher in subjects who had experienced DHF …

Predominance Of Hla-Restricted Cytotoxic T-Lymphocyte Responses To Serotype-Cross-Reactive Epitopes On Nonstructural Proteins Following Natural Secondary Dengue Virus Infection, Anuja Mathew, Ichiro Kurane, Sharone Green, Henry Stephens, David Vaughn, Siripen Kalayanarooj, Saroj Suntayakorn, Dasnayanee Chandanayingyong, Francis Ennis, Alan Rothman

Sharone Green

We examined the memory cytotoxic T-lymphocytic (CTL) responses of peripheral blood mononuclear cells (PBMC) obtained from patients in Thailand 12 months after natural symptomatic secondary dengue virus infection. In all four patients analyzed, CTLs were detected in bulk culture PBMC against nonstructural dengue virus proteins. Numerous CD4+ and CD8+ CTL lines were generated from the bulk cultures of two patients, KPP94-037 and KPP94-024, which were specific for NS1.2a (NS1 and NS2a collectively) and NS3 proteins, respectively. All CTL lines derived from both patients were cross-reactive with other serotypes of dengue virus. The CD8+ NS1.2a-specific lines from patient KPP94-037 were HLA …

B-Cell Responses During Primary And Secondary Dengue Virus Infections In Humans, Anuja Mathew, Kim West, Siripen Kalayanarooj, Robert Gibbons, Anon Srikiatkhachorn, Sharone Green, Daniel Libraty, Smita Jaiswal, Alan Rothman

Sharone Green

Low-avidity serotype-cross-reactive antibodies are hypothesized to play a key role in triggering severe disease in patients with secondary dengue virus (DENV) infection. However, there is little systematic information about the frequency, avidity, and cross-reactivity of DENV-specific B cells in individuals experiencing primary instead of secondary infection. We compared DENV-specific B-cell responses in a cohort of Thai children with primary or secondary DENV infection. B cells specific for DENV precursor membrane protein, envelope (E) protein, and nonstructural protein 1 were detectable in immune peripheral blood mononuclear cells with the highest frequencies of DENV E-specific B cells detected in patients experiencing primary …

Immunopathologic Mechanisms Of Dengue Hemorrhagic Fever And Dengue Shock Syndrome, Ichiro Kurane, Alan Rothman, Peter Livingston, Sharone Green, Susan Gagnon, Jurand Janus, Bruce Innis, Suchitra Nimmannitya, Ananda Nisalak, Francis Ennis

Sharone Green

Dengue virus infections are a major cause of morbidity and mortality in tropical and subtropical areas of the world. The immunopathological mechanisms that result in severe complications of dengue virus infection, i.e. dengue hemorrhagic fever (DHF), are important to determine. Primary dengue virus infections induce serotype-specific and serotype-cross-reactive, CD4+ and CD8+ memory cytotoxic T lymphocytes (CTL). In secondary infections with a virus of a different serotype from that which caused primary infections, the presence of cross-reactive non-neutralizing antibodies results in an increased number of infected monocytes by dengue virus--antibody complexes. This in turn results in marked activation of serotype cross-reactive …