Life Sciences Commons^™

Molecular Evolution Of Dengue Type 2 Virus In Thailand, Rebeca Rico-Hesse, Lisa M. Harrison, Ananda Nisalak, David W. Vaughn, Siripen Kalayanarooj, Sharone Green, Alan L. Rothman, Francis A. Ennis

Sharone Green

Dengue is a mosquito-borne viral infection that in recent years has become a major international public health concern. Dengue hemorrhagic fever (DHF), first recognized in Southeast Asia in the 1950s, is today a leading cause of childhood death in many countries. The pathogenesis of this illness is poorly understood, mainly because there are no laboratory or animal models of disease. We have studied the genetic relationships of dengue viruses of serotype 2, one of four antigenically distinct dengue virus groups, to determine if viruses obtained from cases of less severe dengue fever (DF) have distinct evolutionary origins from those obtained …

Rapid Diagnosis Of Dengue Viremia By Reverse Transcriptase-Polymerase Chain Reaction Using 3'-Noncoding Region Universal Primers, T. Mirawati Sudiro, Hiroaki Ishiko, Sharone Green, Ananda Nisalak, David W. Vaughn, Siripen Kalayanarooj, Alan L. Rothman, Boonyos Raengsakulrach, Jurand Janus, Ichiro Kurane, Francis A. Ennis

Sharone Green

A reverse transcriptase-polymerase chain reaction (RT-PCR) method was developed as a rapid diagnostic test of dengue viremia. To detect dengue viruses in serum or plasma specimens, a pair of universal primers was designed for use in the RT-PCR. Using these primers, the 3'-noncoding region of dengue virus types 1, 2, 3, and 4 could be amplified, but not those of other flaviviruses, such as West Nile virus, Japanese encephalitis virus, and yellow fever virus, or the alphavirus Sindbis virus. The sensitivity of the RT-PCR assay was similar to that of a quantitative fluorescent focus assay of dengue viruses in cell …

Hla Class I Supertype Associations With Clinical Outcome Of Secondary Dengue Virus Infections In Ethnic Thais, Sasijit Vejbaesya, Rungrot Thongpradit, Siripen Kalayanarooj, Komon Luangtrakool, Panpimon Luangtrakool, Robert V. Gibbons, Duangporn Srinak, Somporn Ngammthaworn, Kusuma Apisawes, In-Kyu Yoon, Stephen J. Thomas, Richard G. Jarman, Anon Srikiatkhachorn, Sharone Green, Dasnayanee Chandanayingyong, Sangshin Park, Jennifer Friedman, Alan L. Rothman, Henry A.F. Stephens

Sharone Green

BACKGROUND: Human leukocyte antigen (HLA) supertypes are groups of functionally related alleles that present structurally similar antigens to the immune system.

OBJECTIVES: To analyze HLA class I supertype associations with clinical outcome in hospitalized Thai children with acute dengue illness.

METHODS: Seven hundred sixty-two patients and population-matched controls recruited predominantly in Bangkok were HLA-A and -B typed. HLA supertype frequencies were compared and tested for significant dengue disease associations using logistic regression analyses. Multivariable models were built by conducting forward stepwise selection procedures.

RESULTS: In the final logistic regression model, the HLA-B44 supertype was protective against dengue hemorrhagic fever (DHF) …

Evaluation Of Cardiac Involvement In Children With Dengue By Serial Echocardiographic Studies, Tawatchai Kirawittaya, In-Kyu Yoon, Sineewanlaya Wichit, Sharone Green, Francis A. Ennis, Robert V. Gibbons, Stephen J. Thomas, Alan L. Rothman, Siripen Kalayanarooj, Anon Srikiatkhachorn

Sharone Green

BACKGROUND: Infection with dengue virus results in a wide range of clinical manifestations from dengue fever (DF), a self-limited febrile illness, to dengue hemorrhagic fever (DHF) which is characterized by plasma leakage and bleeding tendency. Although cardiac involvement has been reported in dengue, the incidence and the extent of cardiac involvement are not well defined. METHODS AND PRINCIPAL FINDINGS: We characterized the incidence and changes in cardiac function in a prospective in-patient cohort of suspected dengue cases by serial echocardiography. Plasma leakage was detected by serial chest and abdominal ultrasonography. Daily cardiac troponin-T levels were measured. One hundred and eighty …

The Spatial Dynamics Of Dengue Virus In Kamphaeng Phet, Thailand, Piraya Bhoomiboonchoo, Robert V. Gibbons, Angkana Huang, In-Kyu Yoon, Darunee Buddhari, Ananda Nisalak, Natkamol Chansatiporn, Mathuros Thipayamongkolgul, Siripen Kalanarooj, Timothy Endy, Alan L. Rothman, Anon Srikiatkhachorn, Sharone Green, Mammen P. Mammen, Derek A. Cummings, Henrik Salje

Sharone Green

BACKGROUND: Dengue is endemic to the rural province of Kamphaeng Phet, Northern Thailand. A decade of prospective cohort studies has provided important insights into the dengue viruses and their generated disease. However, as elsewhere, spatial dynamics of the pathogen remain poorly understood. In particular, the spatial scale of transmission and the scale of clustering are poorly characterized. This information is critical for effective deployment of spatially targeted interventions and for understanding the mechanisms that drive the dispersal of the virus.

METHODOLOGY/PRINCIPAL FINDINGS: We geocoded the home locations of 4,768 confirmed dengue cases admitted to the main hospital in Kamphaeng Phet …

Preliminary Evaluation Of Near Infrared Spectroscopy As A Method To Detect Plasma Leakage In Children With Dengue Hemorrhagic Fever, Babs R. Soller, Anon Srikiatkhachorn, Fengmei Zou, Alan L. Rothman, In-Kyu Yoon, Robert V. Gibbons, Siripen Kalayanarooj, Stephen J. Thomas, Sharone Green

Sharone Green

BACKGROUND: Dengue viral infections are prevalent in the tropical and sub-tropical regions of the world, resulting in substantial morbidity and mortality. Clinical manifestations range from a self-limited fever to a potential life-threatening plasma leakage syndrome (dengue hemorrhagic fever). The objective of this study was to assess the utility of near infrared spectroscopy (NIRS) measurements of muscle oxygen saturation (SmO2) as a possible continuous measure to detect plasma leakage in children with dengue.

METHODS: Children ages 6 months to 15 years of age admitted with suspected dengue were enrolled from the dengue ward at Queen Sirikit National Institute for Child Health. …

Sequential Dengue Virus Infections Detected In Active And Passive Surveillance Programs In Thailand, 1994-2010, Piraya Bhoomiboonchoo, Ananda Nisalak, Natkamol Chansatiporn, In-Kyu Yoon, Siripen Kalayanarooj, Mathuros Thipayamongkolgul, Timothy Endy, Alan L. Rothman, Sharone Green, Anon Srikiatkhachorn, Darunee Buddhari, Mammen P. Mammen, Robert V. Gibbons

Sharone Green

BACKGROUND: The effect of prior dengue virus (DENV) exposure on subsequent heterologous infection can be beneficial or detrimental depending on many factors including timing of infection. We sought to evaluate this effect by examining a large database of DENV infections captured by both active and passive surveillance encompassing a wide clinical spectrum of disease.

METHODS: We evaluated datasets from 17 years of hospital-based passive surveillance and nine years of cohort studies, including clinical and subclinical DENV infections, to assess the outcomes of sequential heterologous infections. Chi square or Fisher's exact test was used to compare proportions of infection outcomes such …

Dengue Virus-Specific Human Cd4+ T-Lymphocyte Responses In A Recipient Of An Experimental Live-Attenuated Dengue Virus Type 1 Vaccine: Bulk Culture Proliferation, Clonal Analysis, And Precursor Frequency Determination, Sharone Green, Ichiro Kurane, Robert Edelman, Carol 0. Tacket, Kenneth H. Eckels, David W. Vaughn, Charles H. Hoke, Francis A. Ennis

Sharone Green

We analyzed the CD4+ T-lymphocyte responses to dengue, West Nile, and yellow fever viruses 4 months after immunization of a volunteer with an experimental live-attenuated dengue virus type 1 vaccine (DEN-1 45AZ5). We examined bulk culture proliferation to noninfectious antigens, determined the precursor frequency of specific CD4+ T cells by limiting dilution, and established and analyzed CD4+ T-cell clones. Bulk culture proliferation was predominantly dengue virus type 1 specific with a lesser degree of cross-reactive responses to other dengue virus serotypes, West Nile virus, and yellow fever virus. Precursor frequency determination by limiting dilution in the presence of noninfectious dengue …

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 …

Development Of Antigen-Specific Memory Cd8+ T Cells Following Live-Attenuated Chimeric West Nile Virus Vaccination, Heidi Smith, Thomas Monath, Pamela Pazoles, Alan Rothman, Diane Casey, Masanori Terajima, Francis Ennis, Farshad Guirakhoo, Sharone Green

Sharone Green

ChimeriVax-WN02 is a novel live-attenuated West Nile virus (WNV) vaccine containing modified WNV premembrane (prM) and envelope (E) sequences inserted into the yellow fever 17D vaccine genome. We investigated the induction and evolution of CD8(+) T cell responses to a WNV envelope epitope, which is a dominant target in naturally infected HLA-A*02-positive individuals. WNV epitope-specific CD8(+) T cells were detected by HLA tetramer staining in 22 of 23 donors tested, with peak frequencies occurring between days 14 and 28. WNV epitope-specific T cells evolved from an effector phenotype to a long-lived memory phenotype. In the majority of donors, CD8(+) T …

A Comparative Study Of Leptospirosis And Dengue In Thai Children, Daniel H. Libraty, Khin S. A. Myint, Clinton K. Murray, Robert V. Gibbons, Mammen P. Mammen, Timothy P. Endy, Wenjun Li, David W. Vaughn, Ananda Nisalak, Siripen Kalayanarooj, Duane R. Hospenthal, Sharone Green, Alan L. Rothman, Francis A. Ennis

Sharone Green

BACKGROUND: Leptospirosis is an emerging zoonosis that is often under-recognized in children and commonly confused with dengue in tropical settings. An enhanced ability to distinguish leptospirosis from dengue in children would guide clinicians and public health personnel in the appropriate use of limited healthcare resources. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a prospective, hospital-based, study of children with acute febrile illnesses and dengue in Thailand. Among the children without dengue, we identified those with leptospirosis using anti-leptospira IgM and microscopic agglutination titers in paired acute and convalescent blood samples. We then performed a case-control comparison of symptoms, signs, and clinical laboratory values …

Assessment Of Human Cd4+ And Cd8+ T Lymphocyte Responses In Experimental Viral Vaccine Studies, Alan Rothman, Y. Yamada, Julie Jameson, John Cruz, Kim West, Sharone Green, Francis Ennis

Sharone Green

The traditional in vitro correlate of immunological protection is the induction by a vaccine of neutralizing antibodies against the virus. It was formerly assumed that protection induced by a vaccine was solely due to neutralizing antibodies. Neutralizing antibodies are potent in the prevention of certain diseases, but virus-specific CD4+ T helper cells aid in the proliferation of specific antigen-triggered B cells to make antibodies. CD8+ T cells are responsible for eliminating virus-infected cells during viral illness, and may act as a second line of defence by becoming activated and eliminating any cells that become infected despite the presence of neutralizing …

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 …

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

Sharone Green

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 …

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 …

Dengue Virus-Reactive Cd8+ T Cells Display Quantitative And Qualitative Differences In Their Response To Variant Epitopes Of Heterologous Viral Serotypes, Hema Bashyam, Sharone Green, Alan Rothman

Sharone Green

Reactivation of serotype cross-reactive CD8+ memory T lymphocytes is thought to contribute to the immunopathogenesis of dengue disease during secondary infection by a heterologous serotype. Using cytokine flow cytometry, we have defined four novel HLA-A*02-restricted dengue viral epitopes recognized by up to 1.5% of circulating CD8+ T cells in four donors after primary vaccination. All four donors had the highest cytokine response to the epitope NS4b 2353. We also studied the effect of sequence differences in heterologous dengue serotypes on dengue-reactive CD8+ memory T cell cytokine and proliferative responses. The D3 variant of a different NS4b epitope 2423 and the …

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

Sharone Green

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 …

Long Term Recall Of Memory Cd8 T Cells In Mice To First And Third Generation Smallpox Vaccines, Sharone Green, Francis Ennis, Anuja Mathew

Sharone Green

Since long-term immunity is a critical component of any effective vaccine, we compared over a 15-month period, the strength, durability and specificity of immunity of an attenuated smallpox vaccine Modified Vaccinia Ankara (MVA) to the New York City Board of Health (NYCBH) vaccine. The frequencies of CD8(+) T cells to an immunodominant CD8 T cell epitope B8R(20-27) remained remarkably stable in mice given either MVA or NYCBH. Both groups were also protected from a lethal intranasal challenge with Western Reserve strain of vaccinia virus (VACV-WR). Cytokine responses to virus-specific peptides were detectable with significant boosting upon challenge. Expression of most …

T-Cell Responses To Dengue Virus In Humans, Ichiro Kurane, Takaji Matsutani, Ryuji Suzuki, Tomohiko Takasaki, Siripen Kalayanarooj, Sharone Green, Alan L. Rothman, Francis A. Ennis

Sharone Green

Dengue virus (DENV) is a leading cause of morbidity and mortality in most tropical and subtropical areas of the world. Dengue virus infection induces specific CD4+CD8- and CD8+CD4- T cells in humans. In primary infection, T-cell responses to DENV are serotype cross-reactive, but the highest response is to the serotype that caused the infection. The epitopes recognized by DENV-specific T cells are located in most of the structural and non-structural proteins, but NS3 is the protein that is most dominantly recognized. In patients with dengue hemorrhagic fever (DHF) caused by secondary DENV infection, T cells are highly activated in vivo. …

Prediction Of Dengue Disease Severity Among Pediatric Thai Patients Using Early Clinical Laboratory Indicators, James A. Potts, Robert V. Gibbons, Alan L. Rothman, Anon Srikiatkhachorn, Stephen J. Thomas, Pra-On Supradish, Stephenie C. Lemon, Daniel H. Libraty, Sharone Green, Siripen Kalayanarooj

Sharone Green

BACKGROUND: Dengue virus is endemic in tropical and sub-tropical resource-poor countries. Dengue illness can range from a nonspecific febrile illness to a severe disease, Dengue Shock Syndrome (DSS), in which patients develop circulatory failure. Earlier diagnosis of severe dengue illnesses would have a substantial impact on the allocation of health resources in endemic countries. METHODS AND FINDINGS: We compared clinical laboratory findings collected within 72 hours of fever onset from a prospective cohort children presenting to one of two hospitals (one urban and one rural) in Thailand. Classification and regression tree analysis was used to develop diagnostic algorithms using different …

Robust Intrapulmonary Cd8 T Cell Responses And Protection With An Attenuated N1l Deleted Vaccinia Virus, Anuja Mathew, Joel O'Bryan, William L. Marshall, Girish J. Kotwal, Masanori Terajima, Sharone Green, Alan L. Rothman, Francis A. Ennis

Sharone Green

BACKGROUND: Vaccinia viruses have been used as a model for viral disease and as a protective live vaccine. METHODOLOGY AND PRINCIPAL FINDINGS: We investigated the immunogenicity of an attenuated strain of vaccinia virus engineered to inactivate the N1L gene (vGK5). Using the intranasal route, this recombinant virus was 2 logs less virulent compared to the wildtype VACV-WR. Infection by the intranasal, intraperitoneal, and tail scarification routes resulted in the robust induction of cytolytic virus-specific CD8 T cells in the spleens and the lungs. VACV-specific antibodies were also detected in the sera of mice infected 3-5 months prior with the attenuated …

Cytokine Gene Expression And Protein Production In Peripheral Blood Mononuclear Cells Of Children With Acute Dengue Virus Infections, Susan Gagnon, Masuko Mori, Ichiro Kurane, Sharone Green, David Vaughn, Siripen Kalayanarooj, Saroj Suntayakorn, Francis Ennis, Alan Rothman

Sharone Green

Plasma leakage in dengue hemorrhagic fever (DHF) is associated with elevated plasma levels of cytokines. To define further the contribution of immune activation to DHF and the source of cytokines, we analyzed the production of cytokines in peripheral blood mononuclear cells (PBMC) obtained from children with dengue, using RT-PCR and immunostaining. Tumor necrosis factor-alpha (TNF-alpha) and TNF-beta expression was detected in all samples by PCR and in < 50% of samples by immunostaining. Interferon-gamma (IFN-gamma) expression was detected in < 50% of samples by either method. Interleukin-2 (IL-2) and IL-4 expression was detected in a few samples by immunostaining but was not …

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

Sharone Green

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 …

Cross-Reactivity And Expansion Of Dengue-Specific T Cells During Acute Primary And Secondary Infections In Humans, Heather L. Friberg-Robertson, Hema Sundara Bashyam, Tomoko Toyosaki-Maeda, James A. Potts, Thomas C. Greenough, Siripen Kalayanarooj, Robert V. Gibbons, Ananda Nisalak, Anon Srikiatkhachorn, Sharone Green, Henry A. F. Stephens, Alan L. Rothman, Anuja Mathew

Sharone Green

Serotype-cross-reactive memory T cells responding to secondary dengue virus (DENV) infection are thought to contribute to disease. However, epitope-specific T cell responses have not been thoroughly compared between subjects with primary versus secondary DENV infection. We studied CD8(+) T cells specific for the HLA-A*1101-restricted NS3(133) epitope in a cohort of A11(+) DENV-infected patients throughout acute illness and convalescence. We compared the expansion, serotype-cross-reactivity, and activation of these cells in PBMC from patients experiencing primary or secondary infection and mild or severe disease by flow cytometry. Our results show expansion and activation of DENV-specific CD8(+) T cells during acute infection, which …

Altered Effector Functions Of Virus-Specific And Virus Cross-Reactive Cd8+ T Cells In Mice Immunized With Related Flaviviruses., Derek Trobaugh, Liyan Yang, Francis Ennis, Sharone Green

Sharone Green

Memory cross-reactive CD8+ T-cell responses may induce protection or immunopathology upon secondary viral challenge. To elucidate the potential role of T cells in sequential flavivirus infection, we characterized cross-reactive CD4+ and CD8+ T-cell responses between attenuated and pathogenic Japanese encephalitis virus (JEV) and pathogenic West Nile virus (WNV). A previously reported WNV NS4b CD8+ T-cell epitope and its JEV variant elicited CD8+ T-cell responses in both JEV- and WNV-infected mice. The peptide variant homologous to the immunizing virus induced greater cytokine secretion and activated higher frequencies of epitope-specific CD8+ T cells. However, there was a virus-dependent, peptide variant-independent pattern of …

Identification Of Murine Poxvirus-Specific Cd8+ Ctl Epitopes With Distinct Functional Profiles, Anuja Mathew, Masanori Terajima, Kim West, Sharone Green, Alan Rothman, Francis Ennis, Jeffrey Kennedy

Sharone Green

Murine T cell epitopes against vaccinia virus (VV) have not been characterized to date in part due to the large and complex genome of VV. We have identified and characterized two CD8+ T cell epitopes on the A47L (modified VV Ankara strain (MVA)-029) and J6R (MVA-043) proteins of VV that are Db and Kb restricted, respectively. Following i.p. immunization with VV New York City Board of Health (NYCBH) strain, MVA-029 peptide-stimulated splenocytes secreted IFN-gamma from 7 days to 7 mo postimmunization, and virus-stimulated effectors were also able to lyse MVA-029-pulsed target cells at the same time points. In contrast, MVA-043 …

The Safety And Tolerability Of An Hiv-1 Dna Prime-Protein Boost Vaccine (Dp6-001) In Healthy Adult Volunteers, Jeffrey Kennedy, Mary Co, Sharone Green, Karen Longtine, Jaclyn Longtine, Melissa O'Neill, Janice Adams, Alan Rothman, Qiao Yu, Renita Johnson-Leva, Ranajit Pal, Shixia Wang, Shan Lu, Phillip Markham

Sharone Green

This report describes the safety observations following administration of a polyvalent DNA prime-protein boost HIV-1 vaccine formulated with adjuvant QS21. Local injection site reactions were the most common (65% of subjects), and included type IV delayed-type hypersensitivity (DTH) reactions at prior DNA inoculation sites in 12 of 28 (43%) subjects following protein vaccination. Systemic reactions revealed two cases of vasculitis temporally related to inoculation with recombinant Env protein+QS21 adjuvant. Questions remain regarding the cause of the vasculitis, but the unique DTH observation may have contributed to the high level of immune responses previously reported for this vaccine.

Cross-Subtype Antibody And Cellular Immune Responses Induced By A Polyvalent Dna Prime-Protein Boost Hiv-1 Vaccine In Healthy Human Volunteers, Shixia Wang, Jeffrey Kennedy, Kim West, David Montefiori, Scott Coley, John Lawrence, Siyuan Shen, Sharone Green, Alan Rothman, Francis Ennis, James Arthos, Ranajit Pal, Phillip Markham, Shan Lu

Sharone Green

An optimally effective AIDS vaccine would likely require the induction of both neutralizing antibody and cell-mediated immune responses, which has proven difficult to obtain in previous clinical trials. Here we report on the induction of Human Immunodeficiency Virus Type-1 (HIV-1)-specific immune responses in healthy adult volunteers that received the multi-gene, polyvalent, DNA prime-protein boost HIV-1 vaccine formulation, DP6-001, in a Phase I clinical trial conducted in healthy adult volunteers of both genders. Robust cross-subtype HIV-1-specific T cell responses were detected in IFNgamma ELISPOT assays. Furthermore, we detected high titer serum antibody responses that recognized a wide range of primary HIV-1 …