Cross-Reactive T Cell Immunity to Dengue and Zika Viruses: New Insights Into Vaccine Development

Dengue virus (DENV) is a member of the Flavivirus family that includes Zika virus (ZIKV), West Nile virus, Japanese encephalitis virus, and yellow fever virus. As the most prevalent of the flaviviruses, DENV is responsible for tens of millions of infections each year. The clinical manifestations of infection with one of the four DENV serotypes (DENV1–4) range from no symptoms to hemorrhagic fever and shock (“severe dengue”), which is fatal in ~25,000 patients annually. Many factors contribute to the development of severe dengue, including the DENV serotype and host expression of certain HLA alleles; however, it now seems clear that pre-existing immunity to DENV—and possibly other flaviviruses—is a major precipitating factor. While primary infection with one DENV serotype elicits strong cellular and humoral immune responses that likely confer long-lived protection against the same serotype, subsequent infection with a different serotype carries an increased risk of developing severe dengue. Thus, primary DENV infection elicits cross-reactive immunity that may be protective or pathogenic, depending on the context of the subsequent infection. Many flaviviruses share high sequence homology, raising the possibility that cross-reactive immunity to one virus may contribute to protection against or pathogenesis of a second virus in a similar manner. In addition, several flaviviruses are now endemic in overlapping geographic regions, underscoring the need...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research

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Publication date: May 2019Source: Advances in Chronic Kidney Disease, Volume 26, Issue 3Author(s): Emmanuel A. BurdmannThe genus Flavivirus comprises approximately 73 viruses, which share several common aspects, such as dimension, structure, nucleic acid properties, and shape in electronic microscopy. Global incidence of flavivirus infection increased dramatically over the last decades, causing large outbreaks in several areas of the world. These viruses are expanding from endemic tropical and subtropical areas to previously nonendemic areas, affecting and causing diseases in millions of individuals worldwide and posing a ...
Source: Advances in Chronic Kidney Disease - Category: Urology & Nephrology Source Type: research
Most of the world is at risk of being infected with a flavivirus such as dengue virus, West Nile virus, yellow fever virus, Japanese encephalitis virus, tickborne encephalitis virus, and Zika virus, significantly impacting millions of lives. Importantly, many of these genetically similar viruses co-circulate within the same geographic regions, making it likely for individuals living in areas of high flavivirus endemicity to be infected with multiple flaviviruses during their lifetime. Following a flavivirus infection, a robust virus-specific T cell response is generated and the memory recall of this response has been demon...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
In this study, we evaluated ATA as a potential antiviral drug against ZIKV replication. The antiviral activity of ATA against ZIKV replication in vitro showed median inhibitory concentrations (IC50) of 13.87 ± 1.09 μM and 33.33 ± 1.13 μM in Vero and A549 cells, respectively; without showing any cytotoxic effect in both cell lines (median cytotoxic concentration (CC50)> 1,000 μM). Moreover, ATA protected both cell types from ZIKV-induced cytopathic effect (CPE) and apoptosis in a time- and concentration-dependent manner. In addition, pre-treatment of Vero cells with ATA for up to 72 h also resulted...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
LITFL • Life in the Fast Lane Medical Blog LITFL • Life in the Fast Lane Medical Blog - Emergency medicine and critical care medical education blog aka Tropical Travel Trouble 010 Peer Reviewer: Dr Jennifer Ho, ID physician QLD, Australia You are an ED doc working in Perth over schoolies week. An 18 yo man comes into ED complaining of fever, rash a “cracking headache” and body aches. He has just hopped off the plane from Bali where he spent the last 2 weeks partying, boozing and running amok. He got bitten by “loads” of mosquitoes because he forgot to take insect repellent. On e...
Source: Life in the Fast Lane - Category: Emergency Medicine Authors: Tags: Clinical Cases Tropical Medicine arthralgia dengue fever rash Source Type: blogs
Abstract Most areas of the globe are endemic for at least one flavivirus, putting billions at risk for infection. This diverse group of viral pathogens causes a range of manifestations in humans from asymptomatic infection to hemorrhagic fever to encephalitis to birth defects and even death. Many flaviviruses are transmitted by mosquitos and have expanded in geographic distribution in recent years, with dengue virus being the most prevalent, infecting approximately 400 million people each year. The explosive emergence of Zika virus in Latin America in 2014 refocused international attention on this medically import...
Source: Clinical Therapeutics - Category: Drugs & Pharmacology Authors: Tags: Clin Ther Source Type: research
Serological diagnosis of Zika virus (ZIKV) infections is challenging due to high cross-reactivity between flaviviruses. We evaluated the diagnostic performance of a novel anti-ZIKV ELISA based on recombinant ZIKV non-structural protein 1 (NS1). Assay sensitivity was examined using sera from 27 patients with reverse transcription (RT)-PCR-confirmed and 85 with suspected ZIKV infection. Specificity was analysed using sera from 1,015 healthy individuals. Samples from 252 patients with dengue virus (n?=?93), West Nile virus (n?=?34), Japanese encephalitis virus (n?=?25), chikungunya virus (n?=?19) orPlasmodium spp. (n?=?69) in...
Source: Eurosurveillance - Category: Infectious Diseases Source Type: research
Discussion The current outbreak of ZIKV infections has resulted in a massive effort to accelerate the development of ZIKV specific diagnostics and vaccines. These efforts would benefit greatly from the definition of the specific epitope targets of immune responses in ZIKV, but given the relatively recent emergence of ZIKV as a pandemic threat, few such data are available. We used a large body of epitope data for other Flaviviruses that was available from the IEDB for a comparative analysis against the ZIKV proteome in order to project targets of immune responses in ZIKV and their potential properties. The most common appr...
Source: PLOS Currents Outbreaks - Category: Epidemiology Authors: Source Type: research
CONCLUSIONS ZIKV epidemic poses new challenges to public health, our knowledge about this virus is incipient. In Brazil, a relationship between ZIKV and microcephaly has been mentioned since November 20157 which has not been reported in ZIKV outbreaks in other areas of the world. Several research groups are working on this topic. Guillain Barré Syndrome also has been reported as a complication of ZIKV; however, there are still many questions unanswered regarding the complications caused by this virus. Provide information to the population, following recommendations and preventive measures, taking actions to reduce...
Source: PLOS Currents Outbreaks - Category: Epidemiology Authors: Source Type: research
The rapid spread of Zika virus through the Americas, together with the association of infection with microcephaly and Guillain-Barré syndrome, have propelled this previously ignored virus into the limelight. What is this virus and where did it come from? History Zika virus was first identified in 1947 in a sentinel monkey that was being used to monitor for the presence of yellow fever virus in the Zika Forest of Uganda. At this time, cell lines were not available for studying viruses, so serum from the febrile monkey was inoculated intracerebrally into mice. All the mice became sick, and the virus isolated from thei...
Source: Healthy Living - The Huffington Post - Category: Consumer Health News Source Type: news
The rapid spread of Zika virus through the Americas, together with the association of infection with microcephaly and Guillain-Barré syndrome, have propelled this previously ignored virus into the limelight. What is this virus and where did it come from? History Zika virus was first identified in 1947 in a sentinel monkey that was being used to monitor for the presence of yellow fever virus in the Zika Forest of Uganda. At this time cell lines were not available for studying viruses, so serum from the febrile monkey was inoculated intracerebrally into mice. All the mice became sick, and the virus isolated ...
Source: virology blog - Category: Virology Authors: Tags: Basic virology Information Brazil congenital defect Dengue flavivirus Guillain-Barré microcephaly mosquito vaccine viral viruses yellow fever virus Zika zika virus Source Type: blogs
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