Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genomics-based vaccine could prevent deadly cattle disease

14.02.2006


Every year, East Coast fever destroys the small farmer’s dream of escaping poverty in Africa. Killing more than a million cattle and costing some $200 million annually, this tick-borne disease rages across a dozen countries in eastern and central Africa. Now, an international team of scientists has taken the first major step toward a vaccine to prevent East Coast fever. Their work, published in the February 13-17 early online edition of the Proceedings of the National Academy of Sciences, shows how genomics can generate pivotal new vaccines.



In the study, scientists from five institutions, including The Institute for Genomic Research (TIGR), identify five vaccine targets, or candidate proteins that could form the basis for an East Coast fever subunit vaccine. Based on combined bioinformatics analyses and lab tests, these proteins appear to provide a protective immune response to the disease. "This initiative took just three years, after many years of scientists trying other methods," remarks Vishvanath Nene, a study author and molecular biologist at TIGR. "It’s a huge jump forward."

To make the jump, researchers used the genome sequence of the parasite responsible for East Coast fever. A tick-borne parasite, Theileria parva, causes the disease. When ticks infected with T. parva bite cattle, they transmit the parasite, launching the disease that typically kills cattle within a month. In July, 2005, TIGR led a research team that published T. parva’s genome sequence, representing roughly 4,000 genes, in Science.


In the current study, Nene, along with Malcolm Gardner and Claire Fraser-Liggett, also of TIGR, relied on known biology to search T. parva’s genome for potential vaccine proteins. First, scientists know that immunity to the parasite, and thus East Coast fever, emerges from immune system cells known as killer T cells. Second, they know that T. parva is an intracellular pathogen--it infects and secretes proteins inside cattle white blood cells, which become malignant. The white blood cell then unwittingly passes small fragments of the secreted parasitic proteins associated with a certain type if its own proteins along to its cell surface. And this is where a vaccine could come in: A vaccine made of the T. parva proteins found on the surface of host cells should trigger an immune response in cattle. Vaccinated cattle would then be protected from the parasite.

To find potential vaccine antigens, the TIGR researchers scanned T. parva’s entire genome for genes that make secreted proteins. In particular, they searched for genes that make a "secretion signal," a telltale peptide sequence found at the start of secreted proteins. Sure enough, the scientists found some 400 T. parva genes containing the secretion signal. This set of genes provided a starting pool of candidate proteins. Based on further tests, the study’s research team, led by the International Livestock Research Institute (ILRI) of Nairobi, Kenya, cloned 55 candidate antigen genes and screened those genes for response by killer T cells taken from cattle immune to East Coast fever. To complement TIGR’s gene selection strategy, ILRI also incorporated a random screen of T. parva DNA for vaccine candidates.

In total, the team found five candidate vaccine antigens. In lab tests, these antigens triggered a response from cattle immune killer T cells. Going a further step further, the scientists inoculated cattle with these antigens and then gave the cattle a potentially lethal dose of T. parva. When compared with control animals, vaccinated cattle showed significantly stronger immune response to the parasite.

"This study is a true milestone," says Fraser-Liggett, president of TIGR. "It’s one of the first to take advantage of genomic technologies and build a test vaccine using immune killer T cells as a screening reagent." In addition to TIGR and ILRI, the research team included scientists from: the Ludwig Institute for Cancer Research in Brussels; the Wellcome Trust Center for Human Genetics in Oxford; Sanofi Pasteur in Toronto; the University of Edinburgh; and Merial SAS, an international animal health company. ILRI and Merial have partnered to develop a vaccine against East Coast fever.

By using genomics to understand and fight T. parva, scientists may make advances against related parasites that cause malaria, tuberculosis, and other diseases in which killer T cells also play a role in immunity. What’s more, because T. parva launches a cancer-like illness inside the white blood cells of cattle, it may provide a model system for understanding the mechanics of cancer biology.

But for Nene, who was born in Kenya and worked at ILRI for 15 years before coming to TIGR in 2001, the march against East Coast fever is significant reward, itself. "This disease takes an enormous toll on the local society and economy of rural areas across eastern and central Africa, including Maasai and other pastoral communities," he says.

In particular, East Coast fever kills cattle kept by families trying to rise out of poverty. If researchers are successful, Nene notes, the entire region will have new reason to hope for a better life. Evans Taracha, ILRI project leader, also highlights the importance of strategic research partnerships to overcome this and similar diseases.

Kathryn Brown | EurekAlert!
Further information:
http://www.tigr.org/

More articles from Life Sciences:

nachricht Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine

nachricht New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus 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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>