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:4/5/2017)... 2017 Today HYPR Corp. , leading ... component of the HYPR platform is officially FIDO® ... security architecture that empowers biometric authentication across Fortune 500 ... secured over 15 million users across the financial services ... home product suites and physical access represent a growing ...
(Date:4/4/2017)... 4, 2017   EyeLock LLC , a leader ... United States Patent and Trademark Office (USPTO) has issued ... linking of an iris image with a face image ... the company,s 45 th issued patent. ... timely given the multi-modal biometric capabilities that have recently ...
(Date:3/30/2017)... , March 30, 2017  On April 6-7, 2017, ... the Genome hackathon at Microsoft,s headquarters in ... competition will focus on developing health and wellness apps ... Hack the Genome is the first hackathon ... The world,s largest companies in the genomics, tech and ...
Breaking Biology News(10 mins):
(Date:7/26/2017)... ... July 25, 2017 , ... Proscia Inc. , a software solutions ... featured panelist at 2017 MedCity CONVERGE. His talk, “The Davids vs. the Cancer Goliath,” ... and emerging technology (AI, VR, Big Data) sectors are taking aim at cancer diagnosis ...
(Date:7/26/2017)... ... July 26, 2017 , ... NLP Logix ... years of diagnostic excellence by Mayo Clinic and the experience in developing and ... be distributed through the Microsoft Azure platform and will focus on assisting physicians ...
(Date:7/25/2017)... (PRWEB) , ... July 25, ... ... pleased to welcome Chuck Heinz as Executive Director of Strategic Planning. His ... the Benchworks team. , Chuck’s professional experience encompasses marketing and differentiation consulting, ...
(Date:7/24/2017)... ... July 24, 2017 , ... ... market news outlet had initiated coverage on Interpace Diagnostics. Interpace Diagnostics is ... exposure, progression and risk analysis from specific cancers in humans. , According ...
Breaking Biology Technology: