Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Peptide vaccine fights off breast tumors with aid of bacteria-mimicking agents

05.02.2007
With the help of immune system-stimulating molecules that mimic bacterial components, researchers have used a type of cancer vaccine to both delay and prevent breast tumors in mice. The strategy, they say, holds promise for the future use of peptide vaccines in women who are at high risk for developing breast cancer.

Researchers from the Mayo Clinic, University of South Florida, and University of Torino employed substances called toll-like receptor agonists to help a synthetic peptide vaccine raise the immune system response against breast cancer tumors. Simultaneously, they used antibodies to blunt other aspects of the immune system that might interfere with a strong killer T cell response, improving the effectiveness of the vaccine.

In the February 1 issue of Cancer Research, the researchers report that their strategy was effective in preventing spontaneous tumors in transgenic mouse models for breast cancer, even when the vaccine was given when the mice already had early stage cancer.

"The challenge is to get a foreign peptide recognized by the immune system as a threat so it can react and produce anti-tumor immune cells," said Esteban Celis, M.D., Ph.D., professor in the department of interdisciplinary oncology at the H. Lee Moffitt Cancer Center and Research Institute at the University of South Florida in Tampa. "We've shown that stimulating the immune system using toll-like receptor agonists is very important to alerting it and producing lymphocytes that will have an anti-tumor effect."

According to Celis, the immune system usually doesn't react as strongly to a synthetic peptide in a vaccine as it does against an infectious agent, which is why immune system boosters such as toll-like receptor agonists, which mimic bacterial DNA, help. They also used anti-CD25 antibodies to tie up immune system T regulatory cells, which often serve as brakes that can reduce responses to the vaccine.

The researchers studied both normal mice and transgenic mice carrying an activated HER2/neu oncogene, which has been linked to breast cancer in humans. In order to get a protective immune response, the transgenic mice were repeatedly given vaccine in combination with the toll-like receptor agonist or were given antibodies that blocked their protective T regulatory cells. Celis and his colleagues found that the peptide vaccine administered this way could prevent or slow the growth of injected tumor cells, and showed some benefit against early stage spontaneous breast tumors.

The vaccine was most effective in preventing spontaneous tumors when it was given once at week eight – along with anti-CD25 antibodies -- when most mice have excessive and often precancerous breast tissue growth called hyperplasia. It completely prevented spontaneous tumors in HER2/neu mice up to 35 weeks of age. Even without the antibody, tumors took much longer to develop, and when they did, they grew more slowly.

"This kind of therapy could be applied to women who have a high likelihood of developing cancer -- women with pre-malignant hyperplasia or who have a genetic predisposition or make-up that makes them at high risk," Celis said.

Although the peptide vaccine was effective in preventing spontaneous tumors in the HER2/neu mice, Celis cautions that the mice had to be vaccinated prior to the appearance of measurable tumors and that the animals had to receive repeated immunizations.

"Once tumors appear, only certain mice respond and there is only a delay in tumor growth," he said. "It extends survival but does not cure the mice. We know that the immune response in these mice is much lower than in the animals that are younger, and it's likely that the tumor is making something that is inhibiting the immune response."

Greg Lester | EurekAlert!
Further information:
http://www.aacr.org

Further reports about: Antibodies Celis Peptide Vaccine agonist breast immune system spontaneous

More articles from Life Sciences:

nachricht Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University

nachricht Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>