Navigation Links
Innate immune system targets asthma-linked fungus for destruction
Date:9/2/2008

Blacksburg, Va. A new study shows that the innate immune system of humans is capable of killing a fungus linked to airway inflammation, chronic rhinosinusitis and bronchial asthma. Researchers at Mayo Clinic and the Virginia Bioinformatics Institute (VBI) have revealed that eosinophils, a particular type of white blood cell, exert a strong immune response against the environmental fungus Alternaria alternata. The groundbreaking findings, which shed light on some of the early events involved in the recognition of A. alternata by the human immune system, were published recently in the Journal of Immunology.*

Eosinophils typically combat parasitic invaders of the human body larger than bacteria or viruses, such as flukes or parasitic worms (collectively known as helminths). Evidence from different experimental approaches suggests that asthma and chronic sinusitis can arise when the body perceives that it has encountered a disease-causing organism. Environmental fungi such as Alternaria do not typically cause invasive infections like parasites but for some reason, in certain people, the body responds as if it is being attacked and chronic inflammation can result from the ensuing cascade of immune-related events.

Principal Investigator Hirohito Kita, M.D., from Mayo Clinic, remarked: "Our results strongly demonstrate that eosinophils have the capacity to recognize and exert immunological responses to certain fungi such as Alternaria. We have shown that CD11b receptors on the surface of eosinophils recognize and adhere to beta-glucan, a major cell wall component of the fungus. This in turn sets in motion the release of toxic granule proteins by the white blood cells, leading to extensive damage and ultimate destruction of the fungus. To the best of our knowledge, this is the first time that live eosinophils and not just the intracellular components have been shown to target and destroy a fungus."

The researchers used fluorescence microscopy to determine the outcome of the interaction between eosinophils and A. alternata. The contact of fungus with eosinophils resulted in bright red fluorescence due to the damaged fungal cell wall and subsequent death of Alternaria. Immunohistochemistry confirmed the release of toxic granular proteins by eosinophils due to contact with the fungus.

Dr. Chris Lawrence, Associate Professor at VBI and the Department of Biological Sciences at Virginia Tech, remarked: "T helper 2 (Th2) cells in the immune system typically produce cytokine signaling molecules or interleukins that lead to the recruitment of eosinophils for the dysregulated immune response commonly associated with airway inflammatory disorders. Continual exposure of sensitized individuals to common environmental fungi like Alternaria may result in Th2 cells being constantly activated to recruit eosinophils and this sustained defense mechanism results in chronic inflammation. It has been shown previously that degranulation of eosinophils causes damage of airway mucosa and enhances inflammation. The next step in our transdisciplinary research collaboration will be to use recombinant fungal proteins and fungal knockout mutants for specific genes to dissect the different molecular steps involved in the development and progression of this acute immune response."

Hirohito Kita added: "We have taken an important step in showing that the innate immune system of eosinophils is capable of targeting an asthma-associated fungus for destruction. The biological significance of these results will need to be verified further in animal models and in humans and our collaborative efforts with Dr. Lawrence's research group for proteomics and functional genomics will be invaluable in this respect. We suspect that the dysregulated immune responses to Alternaria, other filamentous fungi, and perhaps chitin-encased insects, such as mites and cockroaches, may play a pivotal role in chronic inflammation and the subsequent development of bronchial airway disease."


'/>"/>

Contact: Barry Whyte
whyte@vbi.vt.edu
540-231-1767
Virginia Tech
Source:Eurekalert

Related medicine news :

1. Protein that provides innate defense against HIV could lead to new treatments
2. VBI, Mayo Clinic investigate link between fungal proteins, innate immunity and asthma
3. Single microRNA fine-tunes innate immune response
4. UNC researcher aims to unmask cancer cells to trigger bodys immune system
5. Immune Response May Hinder Stem Cell Treatments
6. Survivors of 1918 Flu Pandemic Immune 90 Years Later
7. B Cells Can Act Alone in Autoimmune Diseases
8. Targeted drug therapy found effective in patients with common form of immune-mediated kidney disease
9. Hyperactive immune resistance brings blindness in old age
10. Embargoed Until Monday, July 21 at 5 p.m. EST; Scientists Figure Out How the Immune System and Brain Communicate to Control Disease
11. HIV conquers immune system faster than previously realized
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/24/2017)... ... February 24, 2017 , ... The California State University Institute for ... engaged in or interested in palliative care education and research. The Symposium, “Innovate. ... North County San Diego on Sept. 28 and 29, 2017, on the campus of ...
(Date:2/24/2017)... ... February 24, 2017 , ... Rosica ... in thought leadership , media relations, social media, content marketing and SEO, ... be powered through Act-On, an intuitive marketing automation platform. , Rosica will now ...
(Date:2/23/2017)... ... 23, 2017 , ... The 89th Academy Awards will be celebrated this weekend, ... Policy Center Bunkum Award. We invite you to enjoy our 11th annual tongue-in-cheek “salute” ... is the Center for American Progress (CAP), for its report, Lessons From State Performance ...
(Date:2/23/2017)... ... February 23, 2017 , ... Hamlin Dental Group and Dr. ... are sponsoring a raffle. Throughout the month of February, patients who visit Hamlin Dental ... card for a dinner for two at the Cheesecake Factory. , Tickets are ...
(Date:2/23/2017)... ... February 23, 2017 , ... Pink Pig Publishing LLC announces ... and explore the world from different perspectives. By providing a place for people ... understanding, increase empathy, and find greater happiness. , "Our approach to structuring ...
Breaking Medicine News(10 mins):
(Date:2/24/2017)... DUBLIN , Feb. 24, 2017 Research ... Health Market Analysis & Trends - Industry Forecast to 2025" ... ... at a CAGR of around 23.8% over the next decade to ... analyzes the market estimates and forecasts for all the given segments ...
(Date:2/24/2017)... and Markets has announced the addition of the "Hemophilia Drugs Price ... ... Analysis and Strategies - 2016, provides drug pricing data and benchmarks in ... What are the key drugs marketed for Hemophilia ... market? What are the unit prices and annual treatment ...
(Date:2/24/2017)... CUPERTINO, Calif. , Feb. 24, 2017  In ... fourth quarter 2016 financial results press release, you are ... be broadcast live over the internet on Tuesday, March ... Pacific Time). A live audio webcast of ... at www.durect.com and clicking "Investor Relations."  If ...
Breaking Medicine Technology: