Navigation Links
To fight disease, animals, like plants, can tolerate parasites
Date:11/6/2007

Animals, like plants, can build tolerance to infections at a genetic level, and these findings could provide a better understanding of the epidemiology and evolution of infectious disease, according to evolutionary biologists.

Plant pathologists have long known that plants deal with parasites by either developing resistance to the bugs, or by becoming more tolerant to disease. So plants that are tolerant do not get sick as fast as plants that are not tolerant, even when the number of parasites is doubled.

"Think of an aircraft carrier under enemy fire," said Andrew Read, professor of biology and entomology at Penn State, the Eberly College of Science Distinguished Senior Scholar and an associate of the Universitys Center for Infectious Disease Dynamics. "Resistance is trying to repel the incoming shells before they hit." Tolerance, he added, is the number of shells the carrier can withstand before keeling over.

Read and his colleagues Lars Raberg, assistant professor at the University of Lund, and Derek Sim, senior research assistant at Penn State, used the same approach to study tolerance in animals.

They exposed five different strains of mice to malaria, and monitored the rate at which the mice lost weight and red blood cells, a common feature of malarial infections.

The team found that the number of days it took for the parasites to reach peak density when parasite numbers are at a maximum differed in the five mouse strains, indicating varying levels of resistance.

When the researchers analyzed density of red blood cells and minimum weight against the peak density of parasites, they found that as the parasites increased, some mice got sicker more slowly than the others.

"This was the one big a-ha moment, suggesting to us that disease tolerance was at work," said Read, whose findings appear on Nov. 2 in the journal Science.

Researchers were also surprised to find that tolerance and resistance are negatively related. The mice can either kill parasites or tolerate them, but they cannot do both.

Resistance and tolerance are both part of an evolutionary game plan that plants and animals adopt in response to infections, says the Penn State researcher. And in both cases, there is a trade-off.

Resistant hosts are successful in preventing disease but over time the bugs learn to beat them, forcing the hosts to build a stronger resistance. It is a never-ending arms race, noted Read, whose work is funded by the Wellcome Trust and the Swedish Research Council.

"But in the case of tolerance, the host is no longer trying to harm the pathogen, and the arms race stops," he added. Plants and animals simply learn to live with the pathogens.

The Penn State researcher cautions against generalizing the findings but points out that results from the study will provide a better picture of the progression of disease in animals.

While it is not yet clear whether one is better than the other, researchers say that an understanding of disease tolerance and disease resistance could help in picking optimal selection strategies in the breeding of agricultural animals.


'/>"/>

Contact: Amitabh Avasthi
axa47@psu.edu
814-865-9481
Penn State
Source:Eurekalert

Related medicine news :

1. Preclinical study suggests organ-transplant drug may aid in lupus fight
2. Computers help chemists fight emerging infections
3. Study shines more light on benefit of vitamin D in fighting cancer
4. Texas Supreme Court Rules Against Medicare HMOs in Hospital Reimbursement Fight
5. HIV Drug Might Fight Cancer
6. ADA Challenges Marylanders to Step Out to Fight Diabetes Epidemic
7. UVa researcher awarded $3.6 million grant to fight drug-resistant bacteria
8. Drug, Pacemaker Fight Irregular Heartbeat
9. Scripps Research scientists shed new light on how antibodies fight HIV
10. The fight against colorectal cancer
11. Especially Yours and Paula Young Team up with Diahann Carroll and Jaclyn Smith in the Fight Against Breast Cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/24/2017)... ... February 24, 2017 , ... Healthcare Associates of McKinney ... Craig Ranch building at 8080 State Highway 121, Suite 210, McKinney, Texas 75070. ... to Highway 121. , As the practice has grown, the need for more space ...
(Date:2/24/2017)... Diego, CA (PRWEB) , ... February 24, 2017 , ... ... its 2017 national conference convening academic faculty engaged in or interested in palliative care ... and Research,” will be held in North County San Diego on Sept. 28 ...
(Date:2/24/2017)... ... ... Indiana Fiber Network (IFN) President and CEO Kelly C. Dyer recently announced that ... Chairman of the Management Committee when IFN was originally formed in 2002 where he ... and development of the business plan. He became the first paid employee of ...
(Date:2/24/2017)... ... February 24, 2017 , ... Congratulations to ... Elite division on February 12th. Ms. Esparza qualified into this prestigious status ... competition held in Las Vegas, Nevada. Frida is one of approximately 25 gymnasts ...
(Date:2/23/2017)... ... 2017 , ... On February 22, 2017 the U.S. Department ... withdraw previous guidance issued by the Obama Administration requiring schools to treat transgender ... by the Obama Administration came in response to a growing number of states ...
Breaking Medicine News(10 mins):
(Date:2/24/2017)... , Feb. 23, 2017  This report analyzes ... by the following Products: Intermediates, Analytical, ... the report include Pharmaceuticals, and Agrochemicals. The report provides ... , Europe , and Rest ... the period 2015 through 2022. Also, a six-year historic ...
(Date:2/24/2017)... , Feb 24, 2017 Medivir ... proposal for a new Board of Directors that will ... 2016-2017 Nomination Committee comprises representatives of the company,s three ... of 2016 who have accepted a seat on the ... composition of the 2016-2017 Nomination Committee was as follows:  ...
(Date:2/23/2017)... 2017 Visiomed, the French leader in ... is changing the landscape of healthcare with their ... pro-active, custom-made solutions. Recognizing the rising demand of ... healthcare without walls, Visiomed has launched BewellConnect, the ... healthcare professionals that is empowering the lives of ...
Breaking Medicine Technology: