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

How killer immune cells avoid killing themselves

2011-06-10
(Press-News.org) After eight years of work, researchers have unearthed what has been a well-kept secret of our immune system's success. The findings published online on June 9th in Immunity, a Cell Press publication, offer an explanation for how specialized immune cells are able to kill infected or cancerous cells without killing themselves in the process.

The focus of the study is a molecule known as perforin, whose job it is to open up a pore in cells targeted for destruction. With that pore in place, proteases known as granzymes can enter target cells and destroy them.

Perforin is one of the most critical ingredients for a functional immune system. Without it, mice succumb to viral illness and lymphoma. Humans born without a working perforin gene develop an aggressive immunoregulatory disorder in the first few months of life and usually die unless treated with cytoxic drugs or a bone marrow transplant.

But perforin itself is an incredibly destructive molecule. "Perforin forms a massive pore," said Ilia Voskoboinik of the Peter MacCallum Cancer Centre in Australia. "It allows almost any protein to diffuse into a target cell. A few hundred molecules of perforin is sufficient to obliterate any cell."

When the immune cells known as cytotoxic lymphocytes (including cytotoxic T lymphocytes and natural killer cells) are activated, "they produce a massive amount of perforin, yet the cells are fine," Voskoboinik said. The question was: how do our immune cells manage such toxic cargo without endangering themselves?

Before perforin is released, the cells that produce it have to transport it from one part of the cell to another. That transport chain starts in a component of the cell known as the endoplasmic reticulum (ER). From there, it moves to the Golgi and into secretory granules where it is packaged together with granzymes. It is those secretory granules that ultimately fuse with the plasma membrane of the cytotoxic cell and allow its release into the junctions between the immune cell and the cell it aims to kill.

Scientists used to think perforin had an inhibitory domain within its structure that was only removed once they were safely stored in the secretory granules. (The acidic environment within secretory granules keeps perforin inactive until its release.) But Voskoboinik's team purified perforin and found that the protein was always active regardless of whether they had removed the supposed inhibitory domain or not. "It seeded doubt about how perforin is inhibited," he says. "It was a puzzle. Perforin was fully functional but for some reason it couldn't kill the cell [in which it was synthesized]." The real danger zone for the cell when it comes to perforin is the ER, Voskoboinik explained. Conditions there should be ideal for perforin to work, but something keeps it from doing so. The new study links that protection to a single amino acid at one end of the perforin protein. When that amino acid is substituted with another, perforin doesn't make it to the Golgi compartment, it builds up in the ER, and the cell dies. "Perforin goes from zero to extremely high levels within 24 hours and it has everything it needs to be functional," Voskoboinik said. "The cell relies on a really efficient transport system to move perforin away from the danger zone and as a result the cell is absolutely protected."

The findings "close a chapter" in our understanding of the immune system that has existed in the field since perforin was discovered almost 25 years ago, Voskoboinik says. "It was one of those things that was out there on Olympus untouched. Everyone would just stare at it. That's what got us interested."

### END


ELSE PRESS RELEASES FROM THIS DATE:

Avantia Nominated for 2011 British Insurance Awards

Avantia Nominated for 2011 British Insurance Awards
2011-06-10
Following its victory at the 2010 British Insurance Awards, in the Broking Initiative of the Year category, avantia is delighted to announce it's nomination for the 2011 British Insurance Awards - this time in the Business Transformation Deal of the Year category. avantia has been nominated in recognition of a joint initiative with comparison site giant Confused.com which led to the first proper comparison site proposition for people who normally struggle to find insurance because of where they live or their background. "The British Insurance Awards showcase ...

Hormone test helps predict success in IVF

2011-06-10
PROVIDENCE, R.I. [Brown University] — Given how much patients invest in in vitro fertilization (IVF), both financially and emotionally, tools to inform couples about what they might expect during their treatment can be welcome. A study by researchers at Brown University and Women & Infants Hospital shows that as the IVF cycle is beginning, a blood test for levels of a hormone called AMH, or antimullerian hormone, can help predict the number of eggs that will be harvested. "Clinicians can measure AMH before or during ovarian stimulation to counsel couples about their likelihood ...

Want better math teachers? Train them better, says MSU scholar

Want better math teachers? Train them better, says MSU scholar
2011-06-10
EAST LANSING, Mich. — It's time for the United States to consider establishing higher standards for math teachers if the nation is going to break its "vicious cycle" of mediocrity, a Michigan State University education scholar argues in Science magazine. As American students continue to be outpaced in mathematics by pupils in countries such as Russia and Taiwan, William Schmidt recommends adopting more rigorous, demanding and internationally benchmarked teacher-preparation standards for math teachers. "Our research shows that current teacher-preparation programs for ...

Deaths and major morbidity from asbestos-related diseases in Asia likely to surge in next 20 years

2011-06-10
An alarming new article in Respirology issues a serious warning of massive rises in deaths from asbestos-related lung diseases in Asia. Dr Ken Takahashi, Acting Director of the WHO Collaborating Center for Occupational Health, and his team put together important data on asbestos use in 47 Asian countries in this landmark article. Cyprus, Israel and Japan had the highest age-adjusted mortality rates in Asia. This study published in Respirology, a journal of the Asian Pacific Society of Respirology, will serve as an important reference document for health authorities in Asian-Pacific. Asian ...

Inn & Spa at Cedar Falls to Launch Pawpaw Spa Facial, Food and Cocktails

Inn & Spa at Cedar Falls to Launch Pawpaw Spa Facial, Food and Cocktails
2011-06-10
Available beginning September 1, 2011, the Inn & Spa at Cedar Falls will once again offer its wildly popular Pawpaw Spa Facial, along with a special pawpaw menu and pawpaw infused cocktails, all of which debuted to rave reviews in 2010. Inn & Spa at Cedar Falls Spa Director, Randall Wellman LMT, MS, studied the homegrown wild pawpaw and its innate ability to soften and moisturize the skin and provide a natural anti-wrinkle treatment, then developed this proprietary spa facial treatment. "In their spa benefits, pawpaws are a super food ingredient, offering ...

Potential new target for smoking cessation without weight gain

2011-06-10
A new study uncovers a brain mechanism that could be targeted for new medications designed to help people quit smoking without gaining weight. This research, funded by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health, shows that a specific subclass of brain nicotinic receptor is involved in nicotine's ability to reduce food intake in rodents. Prior research shows that the average weight gain after smoking is less than 10 pounds, but fear of weight gain can discourage some people who would like to quit. In the study, to be published ...

Why animals don't have infrared vision

2011-06-10
On rare occasion, the light-sensing photoreceptor cells in the eye misfire and signal to the brain as if they have captured photons, when in reality they haven't. For years this phenomenon remained a mystery. Reporting in the June 10 issue of Science, neuroscientists at the Johns Hopkins University School of Medicine have discovered that a light-capturing pigment molecule in photoreceptors can be triggered by heat, as well, giving rise to these false alarms. "A photon, the unit of light, is just energy, which, when captured by the pigment rhodopsin, most of the time causes ...

Unprecedented international meeting releases preliminary vision for our energy future

2011-06-10
Waterloo, Ontario, Canada, June 9, 2011 – A unique, international summit of scientists, engineers, entrepreneurs and future leaders from around the world has concluded with the release of the Equinox Summit: Energy 2030 Communiqué. The event's preliminary report includes visionary proposals for transformative action to reduce the electricity-related emissions that drive global warming. The full Equinox Communiqué is now available at: http://wgsi.org/files/EquinoxCommunique_June9_2011.pdf The Communiqué identifies a group of technological approaches and implementation ...

A new way to make lighter, stronger steel -- in a flash

2011-06-10
COLUMBUS, Ohio – A Detroit entrepreneur surprised university engineers here recently, when he invented a heat-treatment that makes steel 7 percent stronger than any steel on record – in less than 10 seconds. In fact, the steel, now trademarked as Flash Bainite, has tested stronger and more shock-absorbing than the most common titanium alloys used by industry. Now the entrepreneur is working with researchers at Ohio State University to better understand the science behind the new treatment, called flash processing. What they've discovered may hold the key to making ...

New imaging tech promising for diagnosing cardiovascular disease, diabetes

New imaging tech promising for diagnosing cardiovascular disease, diabetes
2011-06-10
WEST LAFAYETTE, Ind. - Researchers have developed a new type of imaging technology to diagnose cardiovascular disease and other disorders by measuring ultrasound signals from molecules exposed to a fast-pulsing laser. The new method could be used to take precise three-dimensional images of plaques lining arteries, said Ji-Xin Cheng, an associate professor of biomedical engineering and chemistry at Purdue University. Other imaging methods that provide molecular information are unable to penetrate tissue deep enough to reveal the three-dimensional structure of the plaques, ...

LAST 30 PRESS RELEASES:

Inability to pay for healthcare reaches record high in U.S.

Science ‘storytelling’ urgently needed amid climate and biodiversity crisis

KAIST Develops Retinal Therapy to Restore Lost Vision​

Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response

Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid

Low LDL cholesterol levels linked to reduced risk of dementia

Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients

Almost one in ten people surveyed report having been harmed by the NHS in the last three years

Enhancing light control with complex frequency excitations

New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients

New insight into factors associated with a common disease among dogs and humans

Illuminating single atoms for sustainable propylene production

New study finds Rocky Mountain snow contamination

Study examines lactation in critically ill patients

UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award

Doubling down on metasurfaces

New Cedars-Sinai study shows how specialized diet can improve gut disorders

Making moves and hitting the breaks: Owl journeys surprise researchers in western Montana

PKU Scientists simulate the origin and evolution of the North Atlantic Oscillation

ICRAFT breakthrough: Unlocking A20’s dual role in cancer immunotherapy

How VR technology is changing the game for Alzheimer’s disease

A borrowed bacterial gene allowed some marine diatoms to live on a seaweed diet

Balance between two competing nerve proteins deters symptoms of autism in mice

Use of antifungals in agriculture may increase resistance in an infectious yeast

Awareness grows of cancer risk from alcohol consumption, survey finds

The experts that can outsmart optical illusions

Pregnancy may reduce long COVID risk

Scientists uncover novel immune mechanism in wheat tandem kinase

Three University of Virginia Engineering faculty elected as AAAS Fellows

Unintentional drug overdoses take a toll across the U.S. unequally, study finds

[Press-News.org] How killer immune cells avoid killing themselves