Navigation Links
ISU researchers discover cause of immune system avoidance of certain pathogens
Date:8/17/2010

AMES - A special set of sugars found on some disease-causing pathogens helps those pathogens fight the body's natural defenses as well as vaccines, say two Iowa State University researchers.

This discovery may be a first step in understanding a disease family that includes tuberculosis for which there are currently no good vaccines or cures.

Nicola Pohl, professor of chemistry, and Christine Petersen, assistant professor of veterinary pathology, discovered that a natural coating of sugar interacts with the body's defense cells to dampen its own immune response.

The findings are published in the current online issue of the Journal of the American Chemical Society.

Pohl and Petersen began studying persistent pathogens such as tuberculosis and the parasite Leishmania five years ago when they noticed that some types of the parasite can make people sick, while others do not.

"One of the things I was curious about was that pathogenic strains of Leishmania have a different sugar coating on them than nonpathogenic strains," Pohl said.

"We asked the question 'Is it possible that just the sugar coating is enough to make something pathogenic or nonpathogenic?'" she said.

Leishmania-associated diseases are not usually found in the United States, but have been observed in soldiers returning from the Middle East. The diseases can cause unsightly sores, and can last a period of months, according to Pohl.

The diseases are often fatal to dogs in the United States.

"The problem is, in places like Bangladesh, where people are in a nutritionally compromised state, peoples' immune systems aren't strong enough, and the disease can be fatal," said Pohl.

Normally, when a disease-causing agent enters the body, cells called macrophages engulf and start to destroy the agent.

Leishmania-type diseases are resistant to this process.

To test the theory on the resistance effect of the sugar coating, Pohl and Petersen developed an experiment that required creating small beads measuring one micron in diameter to mimic the pathogens.

One group of beads was then coated with a type of sugar that is similar to that of Leishmania. Another set of beads was coated with a lactose-type sugar that isn't harmful to the cell. A third had no coating.

The beads were then introduced into macrophages.

When the uncoated beads were introduced into the macrophages, the cells noticed the beads and started an immune response, as they should.

When the lactose-covered beads were introduced, they were also recognized and removed.

When the Leishmania-sugar covered beads were introduced, the macrophages took a much longer time to recognize their presence. Then, the immune defense system slowed down or dampened the attacks.

This dampening, Petersen and Pohl showed, is due to an interaction between the sugar on the bead and Toll-like receptor2 (TLR2) within the macrophage.

"There is something inherent about the sugars themselves, and the difference in these sugars, that dampens your normal response to the pathogen," said Pohl.

Pohl said they don't yet know exactly what that interaction is or how it works, but she hopes that this research may lead to more research eventually beating the disease.

"Right now we don't have good therapeutics against Leishmaniasis, and we don't have a vaccine for it, so basically you can't do anything about it," she added.

"The more information we have about this, the more we learn about how to circumvent this to get an effective vaccine," she said.

Petersen credits the partnership with Pohl as one of the key factors in understanding the problem.

Pohl's chemistry background doesn't often lead her to look at whole organisms and Petersen, as a veterinary pathologist, previously didn't look at the chemistry.

"Many of these critical sub-molecular interactions are often glossed over by immunologists and biologists," said Petersen. "But the work Nikki and I just published shows that they can make a much larger difference in how a pathogen is sensed by the immune system."


'/>"/>

Contact: Nicola Pohl
npohl@iastate.edu
515-294-2339
Iowa State University
Source:Eurekalert

Related biology news :

1. Researchers develop MRSA-killing paint
2. Researchers discover genetic link between immune system, Parkinsons disease
3. Ben-Gurion U. researchers receive US-AID MERC grant for water project with the Palestinian authority
4. Illinois researchers use pyrosequencing to study canine intestinal bacteria
5. Researchers find that one type of stem cell creates a niche for another type in bone marrow
6. VIB and UGent researchers identify key mechanisms of cell division in plants
7. Rutgers researchers assess severity of prostate cancers using magnetic resonance imaging
8. Carnegie Mellon researchers turn up brightness on fluorescent probes
9. Researchers demonstrate highly directional terahertz laser rays
10. Hebrew University researchers identify gene related to chronic pain
11. UC Riverside researchers measure diesel emissions on the freeway
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/26/2016)... LONDON , April 26, 2016 /PRNewswire/ ... Systems, a product subsidiary of Infosys (NYSE: ... partnership to integrate the Onegini mobile security platform ... http://photos.prnewswire.com/prnh/20151104/283829LOGO ) The integration ... security to access and transact across channels. Using ...
(Date:4/15/2016)... 15, 2016 Research and ... Biometrics Market 2016-2020,"  report to their offering.  , ... , ,The global gait biometrics market is expected ... the period 2016-2020. Gait analysis generates ... be used to compute factors that are not ...
(Date:3/31/2016)... -- Genomics firm Nabsys has completed a financial  restructuring under ... M.D., who returned to the company in October 2015. ... including Chief Technology Officer, John Oliver , Ph.D., ... Vice President of Software and Informatics, Michael Kaiser ... Bready served as CEO of Nabsys from 2005-2014 and ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... 2016 /PRNewswire/ - FACIT has announced the creation ... biotechnology company, Propellon Therapeutics Inc. ("Propellon" or "the ... a portfolio of first-in-class WDR5 inhibitors for the ... WDR5 represent an exciting class of therapies, possessing ... for cancer patients. Substantial advances have been achieved ...
(Date:6/23/2016)... ... 2016 , ... Charm Sciences, Inc. is pleased to announce ... Research Institute approval 061601. , “This is another AOAC-RI approval of the Peel ... President of Regulatory and Industrial Affairs. “The Peel Plate methods perform comparably to ...
(Date:6/23/2016)... SAN FRANCISCO , June 23, 2016   ... it has secured $1 million in debt financing from ... to ramp up automation and to advance its drug ... for its new facility. "SVB has been ... goes beyond the services a traditional bank would provide," ...
(Date:6/23/2016)... ... 2016 , ... In a new case report published today in STEM CELLS ... developed lymphedema after being treated for breast cancer benefitted from an injection of stem ... with this debilitating, frequent side effect of cancer treatment. , Lymphedema refers ...
Breaking Biology Technology: