 |
|
White blood cells are picky about sugar
July 12, 2007Biology textbooks are blunt-neutrophils are mindless killers. These white blood cells patrol the body and guard against infection by bacteria and fungi, identifying and destroying any invaders that cross their path. But new evidence, which may lead to better drugs to fight deadly pathogens, indicates that neutrophils might actually distinguish among their targets.
A scientist in the lab of Whitehead Member Gerald Fink has discovered that neutrophils recognize and respond to a specific form of sugar called beta-1,6-glucan on the surface of fungi. This sugar comprises just a small fraction of the fungal cell wall, much less than another sugar with a slightly different chemical conformation called beta-1,3-glucan. Because the scarce form of the sugar elicits a much stronger reaction from immune cells than the abundant one, it appears that neutrophils can distinguish between two nearly identical chemicals.
"These results show that engulfment and killing by neutrophils varies, depending on cell wall properties of the microbe," explains Whitehead postdoctoral researcher Ifat Rubin-Bejerano, first author on the paper, which appears July 11 in the journal Cell Host & Microbe. "We showed that neutrophils respond in a completely different way to slight changes in sugar composition. If we are able to use this unique sugar to excite the immune system, it may help the human body fight infection."
"Previously, everyone thought that these key cells of the immune system weren't picky and would eat anything that looked foreign," adds Fink, who is also an MIT professor of biology. "Ifat's work has shown that the cells aren't little Pac-Men, but can discriminate one pathogen from another."
Rubin-Bejerano had evidence that neutrophils respond to beta-glucan. After coating tiny beads with a variety of substances (including beta-1,3-glucan and beta-1,6-glucan), she exposed them to the neutrophils and was surprised to see a striking difference in their response to the two sugars. The neutrophils quickly engulfed many of the beads coated with beta-1,6-glucan, but only a few of those covered in beta-1,3-glucan.
Previous studies indicated that blood serum (basically blood minus cells) helps neutrophils recognize their enemies, so Rubin-Bejerano decided to look for clues to their response in this mixture. She identified several proteins in serum that bind to beta-1,6-glucan, but not beta-1,3-glucan, and then pinpointed a molecule on the surface of the neutrophil that recognizes these proteins.
To link her experiments back to real fungi, Rubin-Bejerano worked with the pathogen Candida albicans, which is the most common fungus in blood stream infections. She used an enzyme to digest beta-1,6-glucan from the fungal cell wall, leaving the beta-1,3-glucan intact. She then unleashed the neutrophils on these altered cells and observed a 50 percent reduction in the immune response.
Our bodies maintain a fine balance between the immune system and microbes. Antibiotics and antifungals tilt the balance in favor of the immune system by targeting the microbes directly. A substance like beta-1,6-glucan could help tilt this balance further by stimulating immune cells.
Rubin-Bejerano's work offers hope for combating the growing problem of microbial infections, which can seriously threaten human health-particularly in patients with compromised immune systems. In fact, Rubin-Bejerano co-founded a company called ImmuneXcite to explore this possibility.
Whitehead Institute for Biomedical Research
"Previously, everyone thought that these key cells of the immune system weren't picky and would eat anything that looked foreign," adds Fink, who is also an MIT professor of biology. "Ifat's work has shown that the cells aren't little Pac-Men, but can discriminate one pathogen from another."
Rubin-Bejerano had evidence that neutrophils respond to beta-glucan. After coating tiny beads with a variety of substances (including beta-1,3-glucan and beta-1,6-glucan), she exposed them to the neutrophils and was surprised to see a striking difference in their response to the two sugars. The neutrophils quickly engulfed many of the beads coated with beta-1,6-glucan, but only a few of those covered in beta-1,3-glucan.
Previous studies indicated that blood serum (basically blood minus cells) helps neutrophils recognize their enemies, so Rubin-Bejerano decided to look for clues to their response in this mixture. She identified several proteins in serum that bind to beta-1,6-glucan, but not beta-1,3-glucan, and then pinpointed a molecule on the surface of the neutrophil that recognizes these proteins.
To link her experiments back to real fungi, Rubin-Bejerano worked with the pathogen Candida albicans, which is the most common fungus in blood stream infections. She used an enzyme to digest beta-1,6-glucan from the fungal cell wall, leaving the beta-1,3-glucan intact. She then unleashed the neutrophils on these altered cells and observed a 50 percent reduction in the immune response.
Our bodies maintain a fine balance between the immune system and microbes. Antibiotics and antifungals tilt the balance in favor of the immune system by targeting the microbes directly. A substance like beta-1,6-glucan could help tilt this balance further by stimulating immune cells.
Rubin-Bejerano's work offers hope for combating the growing problem of microbial infections, which can seriously threaten human health-particularly in patients with compromised immune systems. In fact, Rubin-Bejerano co-founded a company called ImmuneXcite to explore this possibility.
Whitehead Institute for Biomedical Research
Neutrophils Current Events and Neutrophils News RSSLSUHSC researcher identifies new target to prevent fatal flu lung complication
Research led by Dr. Jay Kolls, Professor and Chairman of Genetics at LSU Health Sciences Center New Orleans, has identified a therapeutic target for acute lung injury resulting in acute respiratory distress syndrome, a highly fatal complication of influenza infection.
Body's immune system response to dental plaque varies by gender and race
Will neglecting to brush your teeth damage more than just your smile? Can failing to attack dental plaque increase your risk of heart damage?
Reactive Oxygen's Role in Metastasis
Researchers at the Burnham Institute for Medical Research (Burnham) have discovered that reactive oxygen species, such as superoxide and hydrogen peroxide, play a key role in forming invadopodia, cellular protrusions implicated in cancer cell migration and tumor metastasis.
Using insects to test for drug safety
Insects, such as some moths and fruit flies, react to microbial infection in the same way as mammals and so can be used to test the efficiency of new drugs, thereby reducing the need for animal testing.
Breast cancer intervention reduces depression, inflammation
A psychological intervention for newly diagnosed breast cancer patients with symptoms of depression not only relieves patients' depression but also lowers indicators of inflammation in the blood.
Genes key to staph disease severity, drug resistance found hitchhiking together
Scientists studying Staphylococcus bacteria, including methicillin-resistant S. aureus (MRSA), have discovered a potent staph toxin responsible for disease severity.
Genetic Testing May Be Valuable in Treating Colorectal Cancer
For the 29,000 patients in the United States with metastatic colorectal cancer, chemotherapy with irinotecan is a standard treatment that has been shown to improve survival.
Stop and smell the flowers -- the scent really can soothe stress
Feeling stressed? Then try savoring the scent of lemon, mango, lavender, or other fragrant plants.
'First Aid' for Brain Cells Comes From Blood
In acute ischemic stroke, the blood supply to the brain is restricted. Initially, brain cells die from lack of oxygen.
Strategy Discovered for Fighting Persistent Bacterial Infections
Researchers at National Jewish Health have discovered a promising strategy for destroying the molecular scaffolding that can make Pseudomonas bacterial infections extremely difficult to treat in cystic fibrosis patients, wearers of contact lenses, and burn victims. Jerry Nick, MD, Associate Professor of Medicine at National Jewish Health, and his colleagues report in the April 2009 issue of The Journal of Medical Microbiology that a long string of aspartic acid molecules disrupts the molecular bonds that hold together the structure supporting Pseudomonas biofilms.
More Neutrophils Current Events and Neutrophils News Articles
 |
Biochemistry and Physiology of the Neutrophil by Steven W. Edwards (Author) This book describes the role of the neutrophil in infection and inflammation and provides an up-to-date review of the biochemistry and physiology of this cell, highlighting the mechanisms by which they seek out and destroy pathogenic microorganisms. The development of these cells during haematopoiesis is described and the mechanisms that lead to the production of reactive oxidants and the intracellular signal transduction systems that lead to the cell's activation are reviewed. The book also discusses recent discoveries concerning the role of cytokines in the regulation of neutrophil function together with the importance of the neutrophil as a generator of inflammatory cytokines. Finally, there is a description of the biochemical defects that give rise to some of the neutrophil-associated... |
|
The Neutrophil by Patrick Murphy (Author) | |
 |
Biotics Research - Neutrophil Plus 90C by Biotics Research Two  (2) capsules supply: Vitamin A  (as natural mixed carotenoids) . . . . . . . . . . . . . . . . 8,000 IU Vitamin C  (ascorbic acid) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 mg Vitamin E  (as d-alpha tocopheryl aceta |
 |
The Neutrophils: New Outlook For Old Cells by Dmitry I. Gabrilovich (Editor) This is a second edition of the book, which presents an overview of the most recent findings in the biology of neutrophils. These cells are critically important for protection against bacterial and viral infections and have been implicated in anti-tumor response. In addition, neutrophils represent a unique model for studying fundamental questions of cellular biochemistry and molecular biology. This book provides a detailed description of signal transduction, generation of reactive oxygen, and mechanisms of migration of these cells. It contains unique information on the neutrophil’s role in viral infectious diseases and cancer. It also presents the recent advances in attempts to improve neutrophil function and use these cells in the treatment of diseases. |
 |
Neutrophil Methods and Protocols (Methods in Molecular Biology) by Mark T. Quinn (Author), Mark T. Quinn (Editor), Frank R. DeLeo (Editor), Gary M. Bokoch (Editor) Neutrophil Methods and Protocols provides a concise set of protocols for assessing basic neutrophil functions, investigating specialized areas in neutrophil research, and completing step-by-step diagnostic assays of common neutrophil disorders. Each of the protocols is written by leading researchers in the field and includes hints for success, as well as guidance for troubleshooting. Parts 1 & 2 provide an overview of neutrophils the methods most commonly used for isolating them from humans and other animal species. Part 3 details methods for investigating adhesion, chemotaxis, phagocytosis and bacterial activity. Part 4 presents protocols measuring gene expression in neutrophils, and Part 5 concludes with assays for diagnosing the most common neutrophil disorders. Both basic... |
 |
Duralactin Equine 850 gram Bucket by Veterinary Products Laboratories Duralactin Equine is for long term management of chronic inflammatory conditions in horses. Contains MicroLactin that has factors that appear to block cytokines and inhibit neutrophil participation in the inflammatory response. |
 |
Guidance for Standards for Molecular Testing for Red Cell, Platelet, and Neutrophil Antigens, 1st edition by American Association of Blood Banks (AABB) (Author) This guidance is intended to assist in the understanding and practical application of the 1st edition of the Standards for Molecular Testing for Red Cell, Platelet, and Neutrophil Antigens (MT Standards). Primarily, it contains guidance on the quality concepts that provide the framework for the MT Standards. It is also intended to serve as helpful advice or to provide examples of how to implement a specific standard. The Molecular Testing Standards Program Unit has chosen to focus this guidance document on those issues that may be least familiar to members of the molecular testing community. Topics: DNA resources. Targeted nucleotide for neutrophil antigens. Equipment. Supplier and customer issues. Process control. Documents and records. Retention... |
|
The polynuclear count: The nucleus of the neutrophil polymorphonuclear leucocyte in health and disease, with some observations on the macropolycyte by William Edmund Cooke (Author) | |
 |
Inflammation: Pathogen, Burn, Frostbite, Mast cell, Neutrophil granulocyte, Antibody, Phagocytosis, Abscess, Blister, Atherosclerosis, Herpes simplex virus, Glomerulonephritis by John McBrewster (Editor), Frederic P. Miller (Editor), Agnes F. Vandome (Editor) Inflammation - Pathogen, Burn, Frostbite, Mast cell, Neutrophil granulocyte, Antibody, Phagocytosis, Abscess, Blister, Atherosclerosis, Herpes simplex virus, Glomerulonephritis, Pelvic inflammatory disease, Rheumatoid arthritis, Reperfusion injury, Dermatomyositis, Polymyositis, Inclusion body myositis, Selectin, Chemokine, Sepsis, Bacteremia, Eosinophil granulocyte, Meningitis, Keratitis, Laryngitis, Arthritis, Salpingitis, Vaginitis, Gastritis, Gingivitis, Pancreatitis, Mastitis, Epididymitis, Appendicitis, Peritonitis, Pharyngitis, Pyelonephritis, Adhesive capsulitis of shoulder, Encephalitis, Sinusitis, Cholecystitis |
|
Skin signs unite range of innate immunity defects: several disparate skin syndromes appear to share a neutrophil dysfunction genesis.(Clinical Rounds): An article from: Skin & Allergy News by Jeff Evans (Author) This digital document is an article from Skin & Allergy News, published by Thomson Gale on April 1, 2007. The length of the article is 1192 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. Citation Details Title: Skin signs unite range of innate immunity defects: several disparate skin syndromes appear to share a neutrophil dysfunction genesis.(Clinical Rounds) Author: Jeff Evans Publication: Skin & Allergy News (Magazine/Journal) Date: April 1, 2007 Publisher: Thomson Gale Volume: 38 Issue: 4 Page: 36(1) Distributed by Thomson... |
| © 2009 BrightSurf.com |