(Press-News.org) LOS ALAMOS, N. M., March 29, 2013—A new study by Los Alamos National Laboratory and University of Pennsylvania scientists defines previously unknown properties of transmitted HIV-1, the virus that causes AIDS. The viruses that successfully pass from a chronically infected person to a new individual are both remarkably resistant to a powerful initial human immune-response mechanism, and they are blanketed in a greater amount of envelope protein that helps them access and enter host cells.
These findings will help inform vaccine design and interpretation of vaccine trials, and provide new insights into the basic biology of viral/host dynamics of infection.
During the course of each AIDS infection, the HIV-1 virus evolves within the infected person to escape the host's natural immune response and adapt to the local environment within the infected individual. Because HIV evolves so rapidly and so extensively, each person acquires and harbors a complex, very diverse set of viruses that develops over the years of their infection. Yet when HIV is transmitted to a new person from their partner, typically only a single virus from the diverse set in the partner is transmitted to establish the new infection.
The key discoveries here are the specific features that distinguish those specific viruses which successfully move to the new host, compared with the myriad forms in the viral population present in a chronically infected individual.
"The viruses that make it through transmission barriers to infect a new person are particularly infectious and resilient," said Los Alamos National Laboratory scientist Bette Korber. "Through this study we now better understand the biology that defines that resilience."
The team set out to determine whether the viruses that were successfully transmitted to a new patient might share distinct biological properties relative to those typically isolated from people with long-term, chronic infection. To do this, the group at U Penn cloned a set of intact viruses from acute infection, and a set of viruses from chronically infected people, and characterized them by measuring quantities that might be related to the virus's ability to successfully establish a new infection. They discovered several clear correlations. For example, transmitted viruses were both more infectious and contained more protective "envelope" per virus; envelope is the protein the virus uses to enter host cells.
The team identified an additional interesting property that could be a general characteristic of new viral infections: the transmitted HIV was capable of replicating and growing well in the presence of alpha interferon. Alpha interferon production is part of our innate human immune response to a new infection. As soon as a new viral infection is initiated in our bodies, local immune cells at the site of infection start secreting molecules called cytokines that have general antiviral activity and can inhibit the production of the newly infected virus. Alpha interferon is one of these potent cytokines.
In the early days of an HIV infection, this innate immune response increases to an intense level, called a "cytokine storm," which gradually recedes during infection. For a newly transmitted HIV to successfully establish infection, it must grow and expand in the new host while facing this cytokine storm. Although typical chronic viruses are sensitive to and inhibited by alpha interferon, transmitted HIV-1 viruses grew well in the presence of interferon.
Los Alamos scientists Elena Giorgi, James Theiler and Bette Korber were part of the analysis team working closely with investigators at the University of Pennsylvania, Nick Parrish and Beatrice Hahn. The paper, "Phenotypic properties of transmitted founder HIV-1" is in this week's issue of Proceedings of the National Academy of Sciences.
The article was published online before print March 29, 2013, doi: 10.1073/pnas.1304288110 PNAS March 29, 2013 201304288.
Research deciphers HIV attack plan
Scientists get inside look at how AIDS virus grooms its assault team
ELSE PRESS RELEASES FROM THIS DATE:
Newly approved blood thinner may increase susceptibility to some viral infections
CHAPEL HILL, N.C. – A study led by researchers at the University of North Carolina indicates that a newly approved blood thinner that blocks a key component of the human blood clotting system may increase the risk and severity of certain viral infections, including flu and myocarditis, a viral infection of the heart and a significant cause of sudden death in children and young adults. For the past 50 years, people with the heartbeat irregularity, atrial fibrillation, and others at increased risk for forming potentially life-threatening blood clots have been given the ...
Congestion in the Earth's mantle
Jena (Germany) The Earth is dynamic. What we perceive as solid ground beneath our feet, is in reality constantly changing. In the space of a year Africa and America are drifting apart at the back of the Middle Atlantic for some centimeters while the floor of the Pacific Ocean is subducted underneath the South American Continent. "In 100 million years' time Africa will be pulled apart and North Australia will be at the equator," says Prof. Dr. Falko Langenhorst from the Friedrich Schiller University Jena (Germany). Plate tectonics is leading to a permanent renewal of the ...
Researchers discover new clues about how amyotrophic lateral sclerosis develops
Johns Hopkins scientists say they have evidence from animal studies that a type of central nervous system cell other than motor neurons plays a fundamental role in the development of amyotrophic lateral sclerosis (ALS), a fatal degenerative disease. The discovery holds promise, they say, for identifying new targets for interrupting the disease's progress. In a study described online in Nature Neuroscience, the researchers found that, in mice bred with a gene mutation that causes human ALS, dramatic changes occurred in oligodendrocytes — cells that create insulation for ...
New models predict drastically greener Arctic in coming decades
New research predicts that rising temperatures will lead to a massive "greening," or increase in plant cover, in the Arctic. In a paper published on March 31 in Nature Climate Change, scientists reveal new models projecting that wooded areas in the Arctic could increase by as much as 50 percent over the next few decades. The researchers also show that this dramatic greening will accelerate climate warming at a rate greater than previously expected. "Such widespread redistribution of Arctic vegetation would have impacts that reverberate through the global ecosystem," said ...
Pitt team finds immunity protein that ramps up inflammation, and agents that can block it
Scientists at the University of Pittsburgh School of Medicine have discovered a new biological pathway of innate immunity that ramps up inflammation and then identified agents that can block it, leading to increased survival and improved lung function in animal models of pneumonia. They reported their findings today in Nature Immunology. Pneumonia and other infections sometimes provoke an inflammatory response from the body that is more detrimental than the disease-causing bacteria, said senior author Rama Mallampalli, M.D, professor and vice chair for research, Department ...
Is guided self-help effective in treating childhood obesity?
It is known that family-based treatment that combines nutrition and exercise education, along with behavior modification, is a good approach to help children lose weight. But clinic-based weight-control programs for childhood obesity are not accessible to many families, due to issues such as cost or time commitment. Initial studies at the University of California, San Diego School of Medicine indicate that a self-help treatment program for overweight children and their parents, guided by clinical experts, may be an effective solution. The study, led by Kerri Boutelle, ...
Varicella vaccine has long-term effectiveness against chicken pox
OAKLAND, Calif., April 1, 2013 – Chicken pox, the childhood affliction of earlier generations, has been largely neutralized by the varicella vaccine, according to a new study by the Kaiser Permanente Vaccine Study Center, which appears in the current online issue of Pediatrics. The 14-year study followed 7,585 children who were vaccinated in 1995, when they were 12 to 23 months old, to assess the long-term effectiveness of the vaccine and the impact on the epidemiology of varicella (chicken pox) and herpes zoster (shingles). Researchers also observed the impact of the ...
New technique shows promise in restoring near vision without glasses
Philadelphia, Pa. (April 1, 2013) - By middle age, most people have age-related declines in near vision (presbyopia) requiring bifocals or reading glasses. An emerging technique called hyperopic orthokeratology (OK) may provide a new alternative for restoring near vision without the need for glasses, according to a study, "Refractive Changes from Hyperopic Orthokeratology Monovision in Presbyopes", appearing in the April issue of Optometry and Vision Science, official journal of the American Academy of Optometry. The journal is published by Lippincott Williams & Wilkins ...
Jogging Stroller Reviews
Every month, tens of thousands of people are searching for jogging stroller reviews online. Unfortunately, only a handful of websites currently provide legitimate reviews, making it difficult for athletic parents to find unbiased information. "It's a shame; it's hard for athletic parents to find information about jogging strollers. You never know whether you're going to make the right choice when it comes to safety and reliability" says Henry Stinson, one of the staff members at the newly launched website, BestJoggingStrollerReviews.org The site provides ...
Geranium Street Floral: Decorate with Artificial Plants and Flowers
Geranium Street Floral says plants and flowers give a very different feel to any environment: they can add vitality and color to a room that otherwise would be cold, or add serenity to a busy environment, such as a doctor's office waiting room. Bob Smith, general manager of San Marcos, CA-based Geranium Street Floral, says artificial flowers or plants can be placed in key locations, such as a coffee table, a corner of the room or in the eaves of a window, to really add atmosphere. Artificial plants can add an elegant and sophisticated air to a space without creating ...
LAST 30 PRESS RELEASES:
ASH: Novel combination therapy significantly reduces spleen volume in patients with myelofibrosis
ASH: Novel menin inhibitors show promise for patients with advanced acute myeloid leukemias
ASH: Targeted oral therapy reduced disease burden and improved symptoms for patients with rare blood disorder
New Sylvester cancer study provides insight into underlying gene mutations in myelodysplastic syndromes
First-in-human clinical trial of CAR T cell therapy with new binding mechanism shows promising early responses
Long-term results show combination treatment that skips chemotherapy is effective for older patients with Ph+ ALL
Mindfulness could help women with opioid use disorder better control drug urges
TTUHSC’s ARPA-H membership will spur innovation, improve access for West Texas patients
Global annual finance flows of $7 trillion fueling climate, biodiversity, and land degradation crises
Tracing how the infant brain responds to touch with near-infrared spectroscopy
These are the world's most effective charities
When is an aurora not an aurora?
Advisory panel issues field-defining recommendations for US government investments in particle physics research
Doctors discover many patients at UNC’s Inflammatory Bowel Disease Clinic screen positive for malnutrition
BNL: Advisory panel issues field-defining recommendations for U.S. government investments in particle physics research
International collaboration uses faculty member’s research on ancient Roman migration, seeks to understand Balkan genomic history
USF Health Heart Institute doctors are upbeat about cardiac regeneration
AI-driven breakthroughs in cells study: SFU-UBC collaboration introduces "MCS-detect" for advancements in super-resolution microscopy
Advisory panel issues field-defining recommendations for investments in particle physics research
$3.8 million NIH grant to fund Southwest Center on Resilience for Climate Change and Health
What happens when the brain loses a hub?
Study reveals Zika’s shape-shifting machinery—and a possible vulnerability
RIT leading STEM co-mentoring network
Genetic mutations that promote reproduction tend to shorten human lifespan, study shows
CAMH develops potential new drug treatment for multiple sclerosis
Polyethylene waste could be a thing of the past
A dynamic picture of how we respond to high or low oxygen levels
University of Toronto researchers discover new lipid nanoparticle that shows muscle-specific mRNA delivery, reduces off-target effects.
Evolving insights in blood-based liquid biopsies for prostate cancer interrogation
Finding the most heat-resistant substances ever made[Press-News.org] Research deciphers HIV attack plan
Scientists get inside look at how AIDS virus grooms its assault team