Posts tagged vaccine
Articles and news from the latest research reports.
Immune system to fight brain tumours
Research at Lund University in Sweden gives hope that one of the most serious types of brain tumour, glioblastoma multiforme, could be fought by the patients’ own immune system. The tumours are difficult to remove with surgery because the tumour cells grow into the surrounding healthy brain tissue. A patient with the disease therefore does not usually survive much longer than a year after the discovery of the tumour.
The team has tested different ways of stimulating the immune system, suppressed by the tumour, with a ‘vaccine’. The vaccine is based on tumour cells that have been genetically modified to start producing substances that activate the immune system. The modified tumour cells (irradiated so that they cannot divide and spread the disease) have been combined with other substances that form part of the body’s immune system.
The treatment has produced good results in animal experiments: 75 per cent of the rats that received the treatment were completely cured of their brain tumours.
“Human biology is more complicated, so we perhaps cannot expect such good results in patients. However, bearing in mind the poor prognosis patients receive today, all progress is important”, said doctoral student Sara Fritzell, part of the research group led by consultant Peter Siesjö.
She has previously tested combining the activation of the immune system with chemotherapy. When the chemotherapy was applied directly to the tumour site, the positive effects reinforced each other, and a huge 83 per cent of the mice survived.
“Our idea is in the future to give patients chemotherapy locally in conjunction with the operation to remove as much of the tumour as possible”, said Sara Fritzell.
Peter Siesjö is currently applying for permission to carry out a clinical study on stimulation of the immune system – with or without local chemotherapy – as a treatment for patients with glioblastoma multiforme.
(Source: lunduniversity.lu.se)
Major step toward an Alzheimer’s vaccine
A team of researchers from Université Laval, CHU de Québec, and pharmaceutical firm GlaxoSmithKline (GSK) has discovered a way to stimulate the brain’s natural defense mechanisms in people with Alzheimer’s disease. This major breakthrough, details of which are presented today in an early online edition of the Proceedings of the National Academy of Sciences (PNAS), opens the door to the development of a treatment for Alzheimer’s disease and a vaccine to prevent the illness.
One of the main characteristics of Alzheimer’s disease is the production in the brain of a toxic molecule known as amyloid beta. Microglial cells, the nervous system’s defenders, are unable to eliminate this substance, which forms deposits called senile plaques.
The team led by Dr. Serge Rivest, professor at Université Laval’s Faculty of Medicine and researcher at the CHU de Québec research center, identified a molecule that stimulates the activity of the brain’s immune cells. The molecule, known as MPL (monophosphoryl lipid A), has been used extensively as a vaccine adjuvant by GSK for many years, and its safety is well established.
In mice with Alzheimer’s symptoms, weekly injections of MPL over a twelve-week period eliminated up to 80% of senile plaques. In addition, tests measuring the mice’s ability to learn new tasks showed significant improvement in cognitive function over the same period.
The researchers see two potential uses for MPL. It could be administered by intramuscular injection to people with Alzheimer’s disease to slow the progression of the illness. It could also be incorporated into a vaccine designed to stimulate the production of antibodies against amyloid beta. “The vaccine could be given to people who already have the disease to stimulate their natural immunity,” said Serge Rivest. “It could also be administered as a preventive measure to people with risk factors for Alzheimer’s disease.”
"When our team started working on Alzheimer’s disease a decade ago, our goal was to develop better treatment for Alzheimer’s patients," explained Professor Rivest. "With the discovery announced today, I think we’re close to our objective."
(Photo: ALAMY)
Methamphetamine vaccine shows promise
Methamphetamine is one of the most addictive and thus commonly-used street drugs – according to the United Nations Office on Drugs and Crime, there are currently nearly 25 million meth addicts worldwide. Help may be on the way, however. Scientists from The Scripps Research Institute have had success in using a methamphetamine vaccine to block the effects on meth on lab rats.
The vaccine works by allowing the body’s immune system to attack methamphetamine molecules in the bloodstream, keeping them from entering the nervous system. This keeps the meth from affecting the user’s brain, and thus removes the incentive for using the drug.
Ordinarily, meth molecules are too small to evoke an antibody response from the body. The vaccine, known as M6, gets around this by linking a meth-related chemical to a larger carrier molecule that does cause an antibody response. Once the antibodies are in the bloodstream, they attack both the carrier molecules and the actual meth molecules.
In tests on rats, M6 blocked two of the typical effects of the drug – loss of the ability to regulate body temperature, and in increase in physical activity. In another ongoing Scripps study, meth-targeting antibodies were grown in cultured cells in a lab, then injected into rats in a concentrated dose. This approach also blocked the effects of the drug.
More animal trials are planned for now, with the possibility of human trials occurring in the future.