PULLMAN — Disease researchers in Washington State University’s College of Veterinary Medicine have been awarded more than $1.8 million from the Wellcome Trust.
The funding will be used to continue vaccine development for animal diseases that severely limit health, nutrition and economic growth in poorer countries. The Wellcome Trust is the world’s second largest non-governmental supporter of biomedical research. Professor Guy Palmer, based in the WSU veterinary college’s Department of Veterinary Microbiology and Pathology, is the $1,805,004 grant’s principal investigator.
“We’re of course very grateful to receive this grant support,” said Palmer, who is currently on sabbatical leave in Spain. “To me, this is proof WSU is committed to addressing problems like this that have a positive global impact.”
Palmer’s research group for the grant will include faculty and staff at WSU, the University of Florida and at two international institutions in Mexico and Argentina. The Mexican effort will be based at the Centro Nacional de Investigacion Disciplinaria en Parasitologia Veterinaria, and the Argentinean component will reside at the Instutio Nacional de Technologia y Agropecuaria.
“The groups in Mexico and Argentina are led by people who completed their doctoral or postdoctoral training at WSU,” said David Prieur, chair of the Department of Veterinary Microbiology and Pathology. “Collaborations like this that span the globe and help nations less fortunate than ours with colleagues we trained at WSU are very gratifying.”
Palmer’s work is one part of an extraordinary vaccine research effort at WSU’s veterinary college that has been building for more than two decades. The group’s efforts are directed toward vaccine development for animal diseases caused by tick-borne parasites, most notably anaplasmosis and babesiosis. [Pronounced ana-Plaz-mow-sis and baa-BEE-see-oh-sis] Interestingly, babesiosis and that class of diseases includes malaria, the devastating human disease carried by mosquitoes.
Currently, the global cost of tick-borne diseases is estimated to range between $13.9 and $18.7 billion annually. In the developing world, tick-borne diseases sicken and kill large numbers of animals. In the case of anaplasmosis, 90 percent of ticks feeding on an infected animal will acquire the infectious agent and can transmit the disease to other cattle. Disease transmission can occur to cattle with as few as three ticks per animal.
For babesiosis, American farmers are not as affected by the disease and so spend little on cattle to control it. The U.S. Department of Agriculture however maintains a multimillion dollar effort along the Mexican border with some 70 employees to ensure a tick-free zone.
Part of the reason that anaplasmosis and babesiosis remain so destructive rests with their ability to change all or part of their cell surface proteins thereby avoiding detection and control by an animal’s immune system.
Palmer’s group and his international colleagues are focusing on a novel and potentially more effective way to produce better vaccines without many of the risks. This new approach was made possible in part by the work of Kelly Brayton, another WSU veterinary college faculty member in the same department, and her colleagues. Simultaneously, a third group of WSU veterinary faculty scientists and USDA scientists working together, are nearing completion of a major component of the vaccine dilemma.
Brayton, an assistant professor of microbial genetics and her colleagues, determined the complete genetic sequence for Anaplasma marginale, the causative agent for anaplasmosis. Brayton said the genome for the organism is about 2,500 times smaller than the human genome. The group’s work was published in 2004 in the Proceedings of the National Academy of Sciences, acclaimed worldwide as among the most prestigious scientific journals.
If researchers know the complete DNA sequence of an organism, they can potentially develop precise vaccine strains by deleting the genes that allow the wild-type organism to change and remain so virulent and transmissible. The goal is to produce a live vaccine strain of the microorganisms that is as easily transmitted, causes the animal to produce a strong, lasting immune response, but otherwise does not result in disease or production loss.
The third group of WSU and USDA scientists is near completion of the sequencing of the DNA in the microorganism that causes babesiosis, a genetic task some eight times bigger than the A. marginale genome sequence.
Producing a live, vaccine-strain organism is not all there is to the problem. Practical issues come into play to assess the quality of the vaccine in confined animal trials followed by field trials. Then the issues of standardization, supply, international acceptance, costs, labor and distribution follow
“Realistically, I don’t think anyone can accurately say when we will have a safe, effective and inexpensive vaccine destined for widespread use in many nations,” Palmer said. “This means we look at what we do as blocks of accomplishment, all building toward attaining our goals of healthier animals, an abundant, affordable food supply, and an optimized trade status in nations less fortunate than ours. For now, this research direction is a major thrust among all vaccine researchers, and we’re fortunate to have the expertise we have as evidenced by Wellcome’s confidence in WSU with their funding.”
