Breaking News
September 22, 2018 - Finding epigenetic signature appears to predict inflammation risk in serious type of IBD
September 22, 2018 - Researchers develop light-based technique to measure very weak magnetic fields
September 22, 2018 - UAB researchers study dysfunction of the immune system associated with NSAID carprofen
September 22, 2018 - QIAGEN and DiaSorin launch automated, CE-marked workflow for high-throughput TB screening
September 22, 2018 - Cardiac MR With Contrast Feasible in Developing World
September 22, 2018 - Daily low-dose aspirin doesn’t reduce heart-attack risk in healthy people
September 21, 2018 - Children with asthma found to be disadvantaged in education and future occupation
September 21, 2018 - Interaction of chemical slurry and ancient shale in fracking wastewater causes radioactivity
September 21, 2018 - Researchers find that sample size is key factor determining accuracy of study results
September 21, 2018 - Study shows how the drive to eat overpowers the brain’s signal to stop
September 21, 2018 - 30 Million Americans Now Have Diabetes
September 21, 2018 - Thousands of breast cancer gene variants engineered and analyzed
September 21, 2018 - The current fellowship interview process is cumbersome — Stanford researchers have a better idea
September 21, 2018 - Progenitor cells for human bone and cartilage have been identified
September 21, 2018 - Study reveals new therapeutic target for pediatric tumor-associated intractable epilepsy
September 21, 2018 - SLU’s College professor receives NIH grant to develop I-TEST project
September 21, 2018 - DermTech completes enrollment in clinical study to assess DNA damage and reversal
September 21, 2018 - Grieving patients treated with talk therapy have lower risk of suicide and psychiatric illness
September 21, 2018 - NIH and FDA call for eliminating involvement of RAC in human gene therapy experiments
September 21, 2018 - New system uses algorithm to convert 2D videos into 3D printed ‘motion sculptures’
September 21, 2018 - Sea squirt model reveals key molecules in dopaminergic neuron differentiation
September 21, 2018 - Effective management of neonatal abstinence syndrome requires coordinated ‘cascade of care’
September 21, 2018 - Refugees seek care for wounds of war
September 21, 2018 - Under the sea, in an octopus’ garden on ecstacy
September 21, 2018 - Eating foods with low nutritional quality ratings linked to cancer risk in large European cohort
September 21, 2018 - Giving kids honest information about water consumption may help them make healthy choices
September 21, 2018 - Horwitz Prize Awarded for Work on Hormones
September 21, 2018 - CHMP issues positive opinion supporting use of Trelegy Ellipta in broader group of COPD patients
September 21, 2018 - Scientists discover new molecules that work together to remove unwanted DNA
September 21, 2018 - Dr. Fenella France to deliver 2019 Plenary Lecture
September 21, 2018 - New research finds that MHC-II molecules have more influence on tumors than MHC-I
September 21, 2018 - Researchers study effects of cardiac cycle in simple learning task
September 21, 2018 - FDA takes new steps to address opioid crisis by approving Opioid Analgesic Risk Evaluation and Mitigation Strategy
September 21, 2018 - Positive Barhemsys Phase 3 Treatment Data Published in Anesthesia & Analgesia
September 21, 2018 - Celiac Disease Screening: MedlinePlus Lab Test Information
September 21, 2018 - Autism linked to egg cells’ difficulty creating large proteins
September 21, 2018 - Tweaking nuclear pores could provide new avenue to battle against cancer
September 21, 2018 - Experts warn health care providers to slow down in allowing smart pill in patient care settings
September 21, 2018 - MoreGrasp reports breakthrough development of grasp neuroprosthetics activated by thought control
September 21, 2018 - Study reveals new way to target HER2-negative metastatic breast cancer
September 21, 2018 - CHMP grants positive opinion for VENCLYXTO plus rituximab for treating relapsed/refractory CLL
September 21, 2018 - Study offers solid link between visceral organs and brain’s reward, motivation system
September 21, 2018 - First U.S. patient treated with innovative gene therapy at Bascom Palmer Eye Institute
September 21, 2018 - New study shows how Ethiopia has managed to achieve extraordinary progress
September 21, 2018 - Choroidal Detachment – The American Society of Retina Specialists
September 21, 2018 - New clinical trial evaluates aesthetic results of conservative surgery in breast cancer
September 21, 2018 - Discovery of a key protein involved in the development of autism
September 21, 2018 - Air pollution appears to be linked to increased risk of developing dementia
September 21, 2018 - Henry Ford Health System receives $600k grant to study genetic makeup of gliomas
September 21, 2018 - Arthritis common in individuals with varying degrees of depression, finds study
September 21, 2018 - Scientist intends to fight pathogenic bacteria with viruses
September 21, 2018 - New research suggests link between PFAS chemicals and hyperthyroidism in pet cats
September 21, 2018 - Multi-year study data shows impact of new soft contact lens to slow myopia progression in children
September 21, 2018 - Neuroscientists identify circuit for brain’s statistical inference about motion
September 21, 2018 - MILabs’ VECTor6 system wins Commercial Innovation Award at WMIC 2018
September 21, 2018 - Scientists find wild African monkeys infected with bacterium that causes syphilis, yaws in humans
September 21, 2018 - 2006 to 2015 Saw Increase in Severe Maternal Morbidity
September 21, 2018 - Similar changes in the brains of patients with ADHD and emotional instability
September 21, 2018 - Cobalt mining in DR Congo takes a high toll on both creuseurs and environment
September 21, 2018 - Eating fatty fish during pregnancy may boost unborn child’s brain development
September 21, 2018 - Study reveals promising new drug candidate to treat acute renal failure
September 21, 2018 - Neural signal that urges to eat overpowers the one that says to stop
September 21, 2018 - Scientists achieve breakthrough in accelerated diagnosis of multi-resistant hospital pathogens
September 21, 2018 - Researchers simulate how different breast tissues respond to heat from MRIs
September 21, 2018 - Despite red flags at surgery centers, overseers award gold seals
September 21, 2018 - Zapping Airway Nerves May Help COPD Patients Breathe
September 21, 2018 - Researchers find answers as to why some people are at risk of gout
September 21, 2018 - Stars of Stanford Medicine: Genetic counseling and compassion
September 21, 2018 - Researchers use reinforcement learning to train gliders to soar like birds
September 21, 2018 - New federally-funded research project could lead to treatments that extend human lifespan
September 21, 2018 - Health insurance ads have shifted over time due to health plans offered via ACA
September 21, 2018 - Use of transcranial electrical stimulation to bolster creativity has far-reaching implications
September 21, 2018 - Scientists find way to boost efficacy of powerful antimalarial drug with anti-cancer medicines
September 21, 2018 - Weighing the risks and benefits of drug tapering—two patients, two perspectives
September 21, 2018 - The “exposome” revealed: a barrage of bacteria, chemicals, microscopic animals and more
September 21, 2018 - Top three immune boosting recommendations to ward off freshers’ flu
September 21, 2018 - Young children’s oral microbiota could serve as early indicator for obesity
September 21, 2018 - Older individuals with multiple sclerosis report higher quality of life than younger counterparts
September 21, 2018 - LineaRx signs agreement with Takis/Evvivax to develop linear-DNA based anti-cancer vaccines
September 21, 2018 - AbbVie Presents Upadacitinib Longer-Term (32-Week) and Patient-Reported Outcomes Data from Phase 2b Atopic Dermatitis Study at 27th European Academy of Dermatology and Venereology (EADV) Congress
Study reveals how dengue virus replicates without triggering the body’s defenses

Study reveals how dengue virus replicates without triggering the body’s defenses

image_pdfDownload PDFimage_print

A new study reveals how dengue virus manages to reproduce itself in an infected person without triggering the body’s normal defenses. Duke researchers report that dengue pulls off this hoax by co-opting a specialized structure within host cells for its own purposes, like a lazy roommate sneaking bits of his laundry into the communal wash.

Unlike other viruses that flagrantly disrupt the functions of the host in favor of their own needs, dengue appears to be more subtle. It slowly and surreptitiously takes over an accordion-shaped structure inside the cell called the endoplasmic reticulum, the production site for a small subset of host proteins, and steers clear of the larger fluid-filled space of the cell called the cytosol, where most cellular proteins are manufactured.

“It is a remarkably clever thing for a mere 10 kilobases of genetic information,” said Christopher V. Nicchitta, Ph.D., senior study author and professor of cell biology at Duke University School of Medicine. “The virus takes over the machinery and makes a ton of itself, but so slowly and inefficiently that it doesn’t set off any of the sensors the host cell uses to detect when something is awry.”

The study, which appeared January 10 in the Journal of Virology, could point to new strategies to thwart the mosquito-transmitted virus.

According to the World Health Organization, approximately half of the world’s population is at risk of dengue and each year, about 96 million people are sickened by it. No specific treatment for dengue fever currently exists. Decades of vaccine research have been met with disappointment, and recent reports indicate that a new vaccine for dengue could actually worsen the disease rather than prevent it.

“If you can’t make a vaccine, the approach you are left with involves understanding the precise molecular details of the life cycle of these viruses and how they are able to secure and manipulate the host machinery, so you can identify potential drug targets,” said Nicchitta. “It is a more difficult path, but we are beginning to map it out.”

Viruses like dengue are curious entities that exist in a realm between the living and the dead. Though they possess a few hallmarks of life — like proteins and genetic material (DNA or RNA) — they are missing a key one: the ability to reproduce. That’s where host cells come in. Shortly after a virus infects a living cell, it taps into the host’s replication machinery to make more copies of itself. In the case of dengue, one infected host cell can churn out as many as 10,000 viral offspring.

In this study, Nicchitta and his colleagues infected tissue culture cells with a common strain of dengue virus. They then sorted out the cell contents to focus on the two areas where proteins are typically synthesized, the endoplasmic reticulum and the neighboring cytosol. Using advanced molecular techniques, the researchers mapped out the location of the tiny factories known as ribosomes that produce proteins, as well as the RNA template that provides a blueprint for their production.

They found that all the action took place on the surface of the endoplasmic reticulum. The entire genome of the dengue virus is translated in one fell swoop, and then cut up into ten separate proteins. Adding such a complex product to the workload of the endoplasmic reticulum would typically set off its stress sensors. But the researchers discovered that the viral RNA template was translated into protein in such an inefficient, lackadaisical manner, that it didn’t trip those alarms.

“There are features of the RNA that makes it inefficiently translated, so it doesn’t turn on these stress pathways,” Nicchitta said. “Dengue keeps the host cells happy as long as it can. At some point it does gradually overburden the system and the cells will die, but by then the virus has already made tens of thousands of copies of itself.”

Nicchitta is currently trying to pinpoint which features of dengue — its sequence or structure, or both — underlie the slow and steady approach. It may sound counterintuitive, but he says that if the virus were translated more efficiently, it could no longer hide in plain sight. The host cell would notice, and the jig would be up.

Source:

https://today.duke.edu/2018/01/dengue-takes-low-and-slow-approach-replication

Tagged with:

About author

Related Articles