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:10/13/2017)... ... October 13, 2017 , ... Coveros, ... Development, has been awarded a contract by the Center for Medicare and Medicaid ... to accelerate the enterprise use of Agile methodologies in a consistent and high ...
(Date:10/13/2017)... ... October 13, 2017 , ... “America On The Brink”: ... “America On The Brink” is the creation of published author, William Nowers. ... As a WWII veteran, he spent thirty years in the Navy. Following ...
(Date:10/12/2017)... Francisco, CA (PRWEB) , ... October 12, 2017 ... ... Dr. Cheng, are now treating sleep apnea using cutting-edge Oventus O2Vent ... apnea, a serious sleep disorder characterized by frequent cessation in breathing. Oral appliances ...
(Date:10/12/2017)... , ... October 12, 2017 , ... ... to meet the demand of today’s consumer and regulatory authorities worldwide. From Children’s ... experts and tested to meet the highest standard. , These products are ...
(Date:10/12/2017)... Bethesda, MD (PRWEB) , ... October 12, 2017 , ... ... Award of Excellence to Carol Friedman, PhD, FACMI, during the Opening Session of AMIA’s ... 4 – 8. , In honor of Morris F. Collen, a pioneer in the ...
Breaking Medicine News(10 mins):
(Date:10/11/2017)... Texas , Oct. 11, 2017  True ... services, has amplified its effort during National Breast ... about hereditary cancer risks. ... of Clinical Oncology calculated that more than 10 ... have inherited mutations in BRCA1 or BRCA2 and have ...
(Date:10/7/2017)... 6, 2017   Provista, a proven leader ... billion in purchasing power, today announced a new resource ... The Newsroom is the online home for case ... expert bios, news releases, slideshows and events. ... wealth of resources at their fingertips, viewers can also ...
(Date:10/4/2017)... , Oct. 4, 2017 ... single-use, self-contained, illuminating medical devices, today announced regulatory ... Health Surveillance Agency (or Agência Nacional de Vigilância ... first single-use, cordless surgical retractor with integrated LED ... optimal access, illumination and exposure of a tissue ...
Breaking Medicine Technology: