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Researchers have shown that a cold virus known to destroy cancer cells can be delivered to a tumour through the bloodstream without falling prey to killer antibodies on the way.

In a study published Wednesday in the journal Science Translational Medicine, the researchers found the reovirus hitches a ride on blood cells and uses them as a shield against the immune-system cells.

The reovirus holds promise as a possible new way of treating cancer because it not only kills cancer cells directly, but also triggers an immune response similar to what a vaccine does that helps eliminate residual cancer cells.

But because the virus, which causes upper respiratory and gastrointestinal illness, is common in the environment, most people have been exposed to it in childhood and therefore have developed antibodies, said Alan Melcher, a professor of clinical oncology and biotherapy at the University of Leeds in England, who co-led the study.

What people thought that meant was that if youve got antibodies against the virus, if you just inject it into the bloodstream, it can never work because it will just be neutralized by the antibodies, Melcher said Wednesday from Leeds. But what we were able to show, actually, was that by associating with blood cells in the blood, the virus can effectively hide from the antibodies and therefore get transported through the circulation and so get to the tumour.

The study involved 10 patients with advanced colorectal cancer who were due to have surgery on tumours that had spread to the liver. All patients were given up to five intravenous doses of the reovirus in the weeks before their operations.

Blood tests carried out shortly after treatment found the active virus tagging along with blood cells, but later tests showed the virus was quickly cleared from the bloodstream.

However, when researchers looked at the malignant liver tissue removed during surgery up to four weeks later, they found viral factories and active virus in the tumour but not in normal liver tissue.

It seems that reovirus is even cleverer than we had thought. By piggybacking on blood cells, the virus is managing to hide from the bodys natural immune response and reach its target intact, Melcher said. This could be hugely significant for the uptake of viral therapies like this in clinical practice.

The study was not intended to see if the reovirus can shrink or eliminate tumours that question is being explored in much larger trials of patients with a variety of cancers but it does provide proof-of-concept that intravenously delivered reovirus-based cancer therapy is possible, he said.

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Virus’s tricks may beat cancer

PARIS Scientists on Sunday said they had found a key piece in the puzzle as to why a tiny minority of individuals infected with HIV have a natural ability to fight off the deadly AIDS virus.

In a study they said holds promise for an HIV vaccine, researchers from four countries reported the secret lies not in the number of infection-killing cells a person has, but in how well they work.

Only about one person in 300 has the ability to control the human immunodeficiency virus (HIV) without drugs, using a strain of killer cells called cytotoxic T lymphocyte (CTL) cells, previous research has found.

Taking that discovery further, scientists from the United States, Canada, Japan and Germany reported that the strain has molecules called receptors that are better able to identify HIV-infected white blood cells for attack.

Until now, it was well known that people with HIV have tonnes of these killer cells, Bruce Walker, an infectious diseases expert at the Ragon Institute in Massachusetts, told AFP.

We have been scratching our heads since then, asking how, with so many killer cells around, people are getting AIDS. It turns out there is a special quality that makes them (some cells) better at killing.

The study looked at 10 infected people, of whom five took antiretroviral drugs to keep HIV under control while five were so-called elite controllers who remained naturally healthy.

HIV kills a type of white blood cell called CD4, leaving people with AIDS wide open to other, opportunistic and potentially deadly infections.

What we found was that the way the killer cells are able to see infected cells and engage them was different, said Walker.

It is not just that you need a killer cell, what you need is a killer cell with a (T cell) receptor that is particularly good at recognising the infected cell. This gives us a way to understand what it is that makes a really good killer cell.

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Secret of HIV's natural born killers holds promise of vaccine

Scientists say they have found a key piece in the puzzle as to why a tiny minority of individuals infected with HIV have a natural ability to fight off the deadly AIDS virus.

In a study they say holds promise for an HIV vaccine, researchers from four countries have reported the secret lies not in the number of infection-killing cells a person has, but in how well they work.

Only about one person in 300 has the ability to control the human immunodeficiency virus (HIV) without drugs, using a strain of 'killer' cells called cytotoxic T lymphocyte (CTL) cells, previous research has found.

Taking that discovery further, scientists from the United States, Canada, Japan and Germany reported that the strain has molecules called receptors that are better able to identify HIV-infected white blood cells for attack.

Until now, it was well known that people with HIV 'have tonnes of these killer cells', Bruce Walker, an infectious diseases expert at the Ragon Institute in Massachusetts, told AFP.

'We have been scratching our heads since then, asking how, with so many killer cells around, people are getting AIDS. It turns out there is a special quality that makes them (some cells) better at killing.'

The study looked at 10 infected people, of whom five took antiretroviral drugs to keep HIV under control while five were so-called elite controllers who remained naturally healthy.

HIV kills a type of white blood cell called CD4, leaving people with AIDS wide open to other, opportunistic and potentially deadly infections.

'What we found was that the way the killer cells are able to see infected cells and engage them was different,' said Walker.

'It is not just that you need a killer cell, what you need is a killer cell with a (T cell) receptor that is particularly good at recognising the infected cell. This gives us a way to understand what it is that makes a really good killer cell.'

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Secret of HIV's natural born killers out

Published : Tuesday, June 12, 2012 00:00 Article Views : 151 Written by : AFP

PARIS: Scientists said that they had found a key clue on why a tiny minority of individuals infected with HIV (human immunodeficiency virus) has a natural ability to fight off AIDS (Acquired Immune Deficiency Syndrome).

In a study they said holds promise for an HIV vaccine, researchers from four countries reported that the secret lies not in the number of infection-killing cells a person has, but in how well they work.

According to previous research, only about one person in 300 has the ability to control the human immunodeficiency virus (HIV) without drugs, using a strain of killer cells called cytotoxic T lymphocyte (CTL) cells.

Taking that discovery further, scientists from the United States, Canada, Japan and Germany reported that the strain has molecules called receptors that are better able to identify HIV-infected white blood cells for attack.

Until now, it was well-known that people with HIV have tons of these killer cells, Bruce Walker, an infectious diseases expert at the Ragon Institute in Massachusetts, told Agence France-Presse.

We have been scratching our heads since then, asking how, with so many killer cells around, people are getting AIDS. It turns out there is a special quality that makes them [some cells] better at killing, he said.

The study looked at 10 infected people, of whom five took antiretroviral drugs to keep HIV under control while the rest were so-called elite controllers who remained naturally healthy.

HIV kills a type of white blood cell called CD4, leaving people with AIDS wide open to other, opportunistic and potentially deadly infections.

What we found was that the way the killer cells are able to see infected cells and engage them was different, Walker said.

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Secret of HIV killer cells revealed

A parasitic mite helps spread a deadly virus among honey bee colonies.

By Cristina Luiggi | June 11, 2012

A parasitic mite (Varroa destructor) that feeds on the blood of honeybees has helped spread a deadly strain of the virus implicated in the deaths of millions of honeybees worldwide. Known as deformed wing virus (DWV), the RNA virus causes wing and abdominal deformities, suppresses the immune system, and affects the behavior of infected bees.

The mite was accidentally brought over to Hawaii 5 years ago and quickly began affecting honeybee populations, though it has yet to reach all bees on the islandsaffording researchers, led by Stephen Martin from the University of Sheffield, the unique opportunity to study infected and uninfected bee colonies. They found that the mite drastically altered the normal viral landscape of bees, which typically carry billions of different viral strains, and specifically selected for deformed wing virusincreasing its frequency in infected colonies from 10 percent to 100 percent.

Although it remains unclear how the Varroa mite helps the deformed wing virus thrive, the new study, published last week (June 8) in Science, points to effective ways to stop the spread of the virus. So the only way to control the virus is to control the levels of the mite, Martin told BBC News.

By Sabrina Richards

Bees exposed to neonicotinoids, a widely-used class of pesticide, navigate poorly and produce fewer queens, suggesting a role for neonicotinoids in colony collapse.

By Jef Akst

A new subtype of the flu virus is identified in Guatemalan yellow-shouldered bats, and it may share its genes with the human version.

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Honey Bee Killer