PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Targeting amyloid to stop HIV

Compound makes it harder for viral particles to stick to body's cells

2010-09-29
(Press-News.org) Amyloid protein structures are best known for the troubles they pose in the brains of Alzheimer's patients. Now researchers are trying to exploit their presence in a very different place – in semen – to find a new way to stop HIV.

Scientists have created a substance that targets amyloid structures in semen and have used it to weaken the ability of HIV to infect the body's immune cells in the laboratory. The experimental compound, originally designed to help Alzheimer's patients by disrupting the actions of amyloid in the brain, make it much more likely that HIV particles will simply slide past human immune cells instead of gaining a foothold for infection during sexual intercourse

The work by scientists at the University of Rochester Medical Center, in collaboration with chemists at the University of California at San Diego, offers a new lead in the effort to develop a microbicide to prevent HIV transmission from one person to another. The findings were published online recently in the Journal of Biological Chemistry.

The focus of the work is an amyloid structure that was discovered in semen three years ago by German researchers. The structure, known as SEVI for Semen-derived Enhancer of Viral Infection, enhances infection by sticking both to HIV particles and to the immune cells that HIV infects. It's a middle man in the infection process – one that researchers believe is a powerful driver of HIV's ability to infect a person during heterosexual intercourse. SEVI has offered a new target to researchers trying to stop the virus.

"HIV viral particles are tiny and adrift amid a sea of semen and cervical mucus during sexual intercourse," said Stephen Dewhurst, Ph.D., the microbiologist who heads the team. "The virus must sink quickly in this fluid to have the opportunity to contact the cells that it infects.That's what SEVI allows it to do – to literally stick around."

So Dewhurst teamed with Jerry Yang, Ph.D., a chemist at UCSD who previously created a compound designed to minimize the harmful interactions of amyloid with other proteins and lipids in the brain. Yang created a molecule called BTA-EG6 which fits in between the individual small proteins that cluster to form SEVI and blocks SEVI's interactions with both the virus and the target immune cells. One key to the chemistry is the compound ethylene glycol – the central component of anti-freeze – which makes it particularly difficult for SEVI to stick to the virus or to cells.

"The compound drives a wedge between SEVI and both HIV particles and human cells, making it difficult for SEVI to interact with either. It's like surrounding SEVI with air bags so it can't bring HIV and the body's cells together," said Dewhurst. "Jerry Yang is the one who came up with this, and it's ingenious."

In experiments led by first author Joanna Touger Olsen, an M.D./Ph.D. student in the Dewhurst laboratory, the presence of SEVI boosted the ability of HIV to infect cells dramatically, roughly three to six times what it was without SEVI. When the non-stick compound was added, that advantage was muted, and rates of infection dropped nearly to levels when SEVI was absent. The investigators say the results must be interpreted cautiously, though, as the influence of factors such as the strain of HIV and the human cell line used in the study need to be looked at further.

"Other scientists have tried to lower the rate of HIV infection by targeting the virus or the cells it infects," said Yang. "What we do is target the mediator between the virus and the cells. By neutralizing SEVI, we prevent at least one way for HIV to attach to the cells."

The findings come on the heels of work announced by other researchers this summer about a microbicide based on the anti-retroviral agent tenofovir. That compound, when applied by women before and after sex, reduced their risk of contracting HIV by 39 percent.

"Recent studies have shown for the first time that a topical microbicide gel can protect women from HIV-1 infection," said Dewhurst. "This is a huge step forward but not a perfect solution. We need to figure out ways to further improve protection – and our studies suggest one way of doing so. It may be possible to produce a next-generation microbicide that includes both an antiviral agent, as has been used in the past, and an agent that targets SEVI. We're very excited about exploring this idea."

Yang's molecule offers an advantage over most microbicides under study: It doesn't cause inflammation in cervical cells. That's a particular advantage because the cells that drive such inflammation are among precisely the cells that HIV infects.

INFORMATION:

Other authors of the paper from Rochester are laboratory technician Caitlin Brown; Todd Doran, graduate student in Chemistry; Bradley Nilsson, Ph.D., assistant professor of Chemistry; and Rajesh Srivastava, Ph.D., assistant professor of Obstetrics and Gynecology. At UCSD, the team in addition to Yang included Christina Capule and Mark Rubinshtein. The work was funded by the National Institutes of Health and the National Science Foundation.

END



ELSE PRESS RELEASES FROM THIS DATE:

Envious employees can turn hospitality industry hostile

2010-09-29
Guest relationships can become collateral damage when hotel employees envy the relationships co-workers have with their bosses, according to an international team of researchers. In the study of front-line hotel employees -- desk staff, food and beverage workers, housekeepers -- workers who have poor relationships with their bosses were more likely to envy co-workers with better relationships with supervisors, said John O'Neill, associate professor, School of Hospitality Management, Penn State. The study showed that the envious workers were also less likely to help co-workers ...

'Green' concrete developed at Louisiana Tech University on display at Detroit Science Center

2010-09-29
RUSTON, La. – Geopolymer concrete, an innovative and environmentally-friendly building material developed at Louisiana Tech University's Trenchless Technology Center (TTC), will be featured in a transportation exhibition taking place at the Detroit Science Center. Developed by Dr. Erez Allouche, research director for the TTC, and his team, geopolymer concrete is an emerging class of cementitious materials that utilize "fly ash", one of the most abundant industrial by-products, as a substitute for Portland cement, the most widely produced man-made material on earth. "Presenting ...

WMS endorses emergency treatment of anaphylaxis by trained non-medical professionals

2010-09-29
Philadelphia, PA, September 28, 2010 – The Epinephrine Roundtable was convened during the 25th Annual Meeting of the Wilderness Medical Society (WMS) in 2008 to explore areas of consensus and uncertainty in the field treatment of anaphylaxis. The panel endorsed the administration of epinephrine to treat anaphylaxis in the field under emergency conditions by trained non-medical professionals. Anaphylaxis, an acute allergic reaction, is sudden in onset and requires immediate treatment. The recommendations of the panel are published in the September issue of Wilderness & Environmental ...

'Firefly' stem cells may help repair damaged hearts

Firefly stem cells may help repair damaged hearts
2010-09-29
Stem cells that glow like fireflies could someday help doctors heal damaged hearts without cutting into patients' chests. In his University of Central Florida lab, Steven Ebert engineered stem cells with the same enzyme that makes fireflies glow. The "firefly" stem cells glow brighter and brighter as they develop into healthy heart muscle, allowing doctors to track whether and where the stem cells are working. Researchers are keenly interested in stem cells because they typically morph into the organs where they are transplanted. But why and how fast they do it is ...

Individual mutations are very slow to promote tumor growth

2010-09-29
CAMBRIDGE, Mass., Sept. 28, 2010 -- Individual cancer-causing mutations have a minute effect on tumor growth, increasing the rate of cell division by just 0.4 percent on average, according to new mathematical modeling by scientists at Harvard University, Johns Hopkins University, and other institutions. Their research, appearing this week in the Proceedings of the National Academy of Sciences, reinforces that cancer is the culmination of many accumulated mutations. It also highlights the fundamental heterogeneity and randomness of many cancers, consistent with the observations ...

Rebels without applause: New study on peer victimization

2010-09-29
Montreal September 28, 2010 – Loners and antisocial kids who reject other children are often bullied at school – an accepted form of punishment from peers as they establish social order. Such peer victimization may be an extreme group response to control renegades, according to a new study from Concordia University published in the Journal of Early Adolescence. "For groups to survive, they need to keep their members under control," says author William M. Bukowski, a professor at the Concordia Department of Psychology and director of its Centre for Research in Human Development. ...

New study reveals that insecticides from genetically modified corn are present in adjacent streams

2010-09-29
A new study by University of Notre Dame ecologist Jennifer Tank and colleagues reveals that streams throughout the Midwest are receiving transgenic materials from corn crop byproducts, even six months after harvest. Transgenic maize (corn) has been genetically engineered to produce its own insecticide, a delta endotoxin from the bacterium Bacillus thuringiensis (Bt). Bt endotoxins deter crop pests, such as the European corn borer. In a 2007 paper in the Proceedings of the National Academy of Science (PNAS), Tank and a group of researchers demonstrated that transgenic ...

Certain psychiatric disorders linked with risky sexual behavior in teens

2010-09-29
EAST PROVIDENCE, RI – Although research has shown that teens with mental health disorders are more likely to engage in high risk sexual behaviors, like unprotected sex, a new study from the Bradley Hasbro Children's Research Center suggests there is an additional risk associated with certain psychiatric diagnoses. According to researchers, teens who experience the manic phase of bipolar disorder – which is marked by dramatic mood swings from euphoria and elation to irritability – are more sexually active, have more sexual partners and are more likely to have a sexually ...

CWRU's e-SMART technologies may help young adults self-manage mental illness

2010-09-29
While many young adults will share the details of their daily lives with dozens – sometimes hundreds – of friends on Facebook, communicating with their health care providers about mental illness is another story. "Roughly one in every five young adults between 18 and 25 has a mental illness," says Melissa Pinto-Foltz, a postdoctoral scholar and instructor at the Frances Payne Bolton School of Nursing at Case Western Reserve University. "Seventy percent of them don't receive treatment. Of those that do receive treatment, they have trouble managing the illness and often ...

Researchers confirm prenatal heart defects in spinal muscular atrophy cases

2010-09-29
COLUMBIA, Mo. – University of Missouri researchers believe they have found a critical piece of the puzzle for the treatment of Spinal Muscular Atrophy (SMA) – the leading genetic cause of infantile death in the world. Nearly one in 6,000 births has SMA, and it is estimated that nearly one in 30 to 40 people have the trait that leads to SMA. In a new study in Human Molecular Genetics, Christian Lorson, professor in the Department of Veterinary Pathobiology and the Department of Molecular Microbiology and Immunology, has found prenatal cardiac defects in mice with SMA. Lorson ...

LAST 30 PRESS RELEASES:

Study identifies candidates for therapeutic targets in pediatric germ cell tumors

Media alert: The global burden of CVD

Study illuminates contributing factors to blood vessel leakage

What nations around the world can learn from Ukraine

Mixing tree species does not always make forests more drought-resilient

Public confidence in U.S. health agencies slides, fueled by declines among Democrats

“Quantum squeezing” a nanoscale particle for the first time

El Niño spurs extreme daily rain events despite drier monsoons in India

Two studies explore the genomic diversity of deadly mosquito vectors

Zebra finches categorize their vocal calls by meaning

Analysis challenges conventional wisdom about partisan support for US science funding

New model can accurately predict a forest’s future

‘Like talking on the telephone’: Quantum computing engineers get atoms chatting long distance

Genomic evolution of major malaria-transmitting mosquito species uncovered

Overcoming the barriers of hydrogen storage with a low-temperature hydrogen battery

Tuberculosis vulnerability of people with HIV: a viral protein implicated

Partnership with Kenya's Turkana community helps scientists discover genes involved in adaptation to desert living

Decoding the selfish gene, from evolutionary cheaters to disease control

Major review highlights latest evidence on real-time test for blood – clotting in childbirth emergencies

Inspired by bacteria’s defense strategies

Research spotlight: Combination therapy shows promise for overcoming treatment resistance in glioblastoma

University of Houston co-leads $25 million NIH-funded grant to study the delay of nearsightedness in children

NRG Oncology PREDICT-RT study completes patient accrual, tests individualized concurrent therapy and radiation for high-risk prostate cancer

Taking aim at nearsightedness in kids before it’s diagnosed

With no prior training, dogs can infer how similar types of toys work, even when they don’t look alike

Three deadliest risk factors of a common liver disease identified in new study

Dogs can extend word meanings to new objects based on function, not appearance

Palaeontology: South American amber deposit ‘abuzz’ with ancient insects

Oral microbes linked to increased risk of pancreatic cancer

Soccer heading does most damage to brain area critical for cognition

[Press-News.org] Targeting amyloid to stop HIV
Compound makes it harder for viral particles to stick to body's cells