Breaking News
January 21, 2019 - FDA Advisory Committee Votes on Zynquista (sotagliflozin) as Treatment for Adults with Type 1 Diabetes
January 21, 2019 - The causes and complications of snoring
January 21, 2019 - Placenta adapts and compensates when pregnant mothers have poor diets or low oxygen
January 21, 2019 - New implant could restore the transmission of electrical signals in injured central nervous system
January 21, 2019 - Rapid-acting fentanyl test strips found to be effective at reducing overdose risk
January 21, 2019 - Coronary Artery Calcium May Help Predict CVD in South Asians
January 21, 2019 - The mystery of the super-ager
January 21, 2019 - Scientists develop smart microrobots that can change shape depending on their surroundings
January 21, 2019 - Keep Moving to Keep Brain Sharp in Old Age
January 21, 2019 - Despite progress, gay fathers and their children still structurally stigmatized
January 21, 2019 - Merck recognized with 2018 Life Science Industry Award for best use of social media
January 21, 2019 - Coeur Wallis equips the canton of Valais with 260 SCHILLER defibrillators
January 21, 2019 - Scientists propose quick and pain-free method for diagnosing kidney cancer
January 21, 2019 - Signs of memory loss could point to hearing issues
January 21, 2019 - HeartFlow Analysis shows highest diagnostic performance for detecting coronary artery disease
January 21, 2019 - How Much Caffeine is Too Much?
January 21, 2019 - Take a timeout before you force your child to apologize
January 21, 2019 - Scientists design two AI algorithms to improve early detection of cognitive impairment
January 21, 2019 - Novel therapy for children with chronic hormone deficiency provides lifeline for parents
January 21, 2019 - Bioethicists call for oversight of poorly regulated, consumer-grade neurotechnology products
January 21, 2019 - Study shows hereditary hemochromatosis behind many cancers and joint diseases
January 21, 2019 - Short bouts of stairclimbing throughout the day can improve cardiovascular health
January 20, 2019 - Liver Transplant Survival May Improve With Race Matching
January 20, 2019 - Study implicates hyperactive immune system in aging brain disorders
January 20, 2019 - Cancer Diagnosis May Quadruple Suicide Risk
January 20, 2019 - Parkinson’s disease experts devise a roadmap
January 20, 2019 - Research brings new hope to treating degenerative brain diseases
January 20, 2019 - Scientists pinpoint a set of molecules that wire the body weight center of the brain
January 20, 2019 - Researchers get close to developing elusive blood test for Alzheimer’s disease
January 20, 2019 - UCLA researchers demonstrate new technique to develop cancer-fighting T cells
January 20, 2019 - Researchers discover how cancer cells avoid genetic meltdown
January 20, 2019 - Exercise makes even the ‘still overweight’ healthier: study
January 20, 2019 - University of Utah to establish first-of-its-kind dark sky studies minor in the US
January 20, 2019 - School-based nutritional programs reduce student obesity
January 20, 2019 - Improved maternity care practices in the southern U.S. reduce racial inequities in breastfeeding
January 20, 2019 - New enzyme biomarker test indicates diseases and bacterial contamination
January 20, 2019 - Republican and Democratic governors have different visions to transform health care, say researchers
January 20, 2019 - Researchers discover that spin flips happen in only half a picosecond in the course of a chemical reaction
January 20, 2019 - Suicide Risk Up More Than Fourfold for Cancer Patients
January 20, 2019 - Doctors find 122 nails in Ethiopian’s stomach
January 20, 2019 - UV disinfection technology eliminates up to 97.7% of pathogens in operating rooms
January 20, 2019 - Researchers discover mechanism which drives leukemia cell growth
January 20, 2019 - AHA: Infection as a Baby Led to Heart Valve Surgery for Teen
January 20, 2019 - Injection improves vision in a form of childhood blindness
January 20, 2019 - Multiple sclerosis therapies delay progression of disability
January 20, 2019 - New study finds infrequent helmet use among bike share riders
January 20, 2019 - Clearing up information about corneal dystrophies
January 20, 2019 - Researchers describe new behavior in energy metabolism that refutes existing evidence
January 20, 2019 - New study takes first step toward treating endometriosis
January 20, 2019 - Researchers find how GREB1 gene promotes resistance to prostate cancer treatments
January 20, 2019 - Replacing Sitting Time With Activity Lowers Mortality Risk
January 20, 2019 - A simple, inexpensive intervention makes birth safer for moms and babies in parts of Africa
January 19, 2019 - New anti-inflammatory compound acts as ‘surge protector’ to reduce cancer growth
January 19, 2019 - Significant flaws found in recently released forensic software
January 19, 2019 - New Leash on Life? Staying Slim Keeps Pooches Happy, Healthy
January 19, 2019 - Men and women remember pain differently
January 19, 2019 - Rising air pollution linked with increased ER visits for breathing problems
January 19, 2019 - Study uses local data to model food consumption patterns among Seattle residents
January 19, 2019 - The brain’s cerebellum plays role in controlling reward and social behaviors, study shows
January 19, 2019 - Relationship between nurse work environment and patient safety
January 19, 2019 - Pioneering surgery restores movement to children paralyzed by acute flaccid myelitis
January 19, 2019 - Genetic variants linked with risk tolerance and risky behaviors
January 19, 2019 - New research provides better understanding of our early human ancestors
January 19, 2019 - First-ever tailored reporting guidance to improve patient care and outcomes
January 19, 2019 - 4.6 percent of Massachusetts residents have opioid use disorder
January 19, 2019 - New study suggests vital exhaustion as risk factor for dementia
January 19, 2019 - New antibiotic discovery heralds breakthrough in the fight against drug-resistant bacteria
January 19, 2019 - Ural Federal University scientists synthesize a group of multi-purpose fluorophores
January 19, 2019 - Researchers identify new therapeutic target in the fight against chronic liver diseases
January 19, 2019 - Preparation, characterization of Soyasapogenol B loaded onto functionalized MWCNTs
January 19, 2019 - FDA Approves Ontruzant (trastuzumab-dttb), a Biosimilar to Herceptin
January 19, 2019 - Tobacco use linked with higher use of opioids and sedatives
January 19, 2019 - Study delves deeper into developmental dyslexia
January 19, 2019 - Anti-vaccination movement one of the top health threats in 2019 says WHO
January 19, 2019 - Newly developed risk score more effective at identifying type 1 diabetes
January 19, 2019 - Highly effective protocol to prepare cannabis samples for THC/CBD analysis
January 19, 2019 - Prinston Pharmaceutical Inc. Issues Voluntary Nationwide Recall of Irbesartan and Irbesartan HCTZ Tablets Due to Detection of a Trace Amount of Unexpected Impurity, N-Nitrosodiethylamine (NDEA) in the Products
January 19, 2019 - How does solid stress from brain tumors cause neuronal loss, neurologic dysfunction?
January 19, 2019 - $14.7 million partnership to supercharge vaccine development
January 19, 2019 - Ian Fotheringham receives Charles Tennant Memorial Lecture award
Ground-breaking discovery finds new link between autoimmune diseases and a gut bacterium

Ground-breaking discovery finds new link between autoimmune diseases and a gut bacterium

image_pdfDownload PDFimage_print
Credit: CC0 Public Domain

Could microbes in our guts be sending out the wrong message? Queen’s University Belfast researchers have, for the first time, found a specific microbe in the gut that pumps out protein molecules that mimic a human protein, causing the human defence system to turn on its own cells by mistake.

The culprit in this case is called Bacteroides fragilis, a bacterium that normally lives in the human gut. The Queen’s team has shown that this bacterium produces a human-like protein that could trigger autoimmune diseases, such as rheumatoid arthritis. This human protein is called ‘ubiquitin’ and is needed for all the normal cell processes in our bodies

The study, recently published in the British Society for Immunology journal Clinical and Experimental Immunology is a significant discovery. “Mimic proteins” fool our immune defence system into reacting with our own bodies, resulting in autoimmune disease, a condition in which your immune system mistakenly attacks the body.

More than 80 different types of autoimmune diseases are known to exist including; rheumatoid arthritis; multiple sclerosis; and lupus. Many hundreds of thousands of people world-wide currently suffer from these debilitating and painful conditions, that currently have no cure.

In an autoimmune disease, our immune system mistakenly attacks the body. Antibodies that are part of the immune system usually target bacteria or viruses, but get misdirected in people with autoimmune diseases. They become ‘autoantibodies’ that can attack healthy parts of the body, including different parts of the body in lupus or just the joints in the case of rheumatoid arthritis.

Professor Sheila Patrick, Professor Emeritus at Queen’s University explained: “When we mapped the genome of Bacteroides fragilis a few years ago we were astonished to discover a human-like gene not present in any other bacteria. The protein produced from this gene is nearly the same shape as a protein in almost every human cell.”

“When we discovered that Bacteroides fragilis produces lots of this mimic protein we were very excited. No other bacteria produced a mimic of human ubiquitin and this one lives in our gut. We immediately wondered if it might be linked with autoimmune diseases such as lupus. It has been known since the 1990s that some people with autoimmune diseases have antibodies that target their own human ubiquitin, but we don’t know why this happens. So we decided to see if people also had antibodies that target the Bacteroides fragilis version of ubiquitin.”

The recently published study is a collaboration with Dr. Linda Stewart, Lecturer at the School of Biological Science and Institute for Global Food Security at Queen’s University Belfast, Dr. David Edgar Consultant Immunologist and Head of the Northern Ireland Regional Immunology Service and Dr. Garry Blakely Senior Lecturer at the University of Edinburgh.

Dr. Linda Stewart continued: “We have found that some people with autoimmune disease have high levels of antibodies to the bacterial mimic of ubiquitin. It is also possible to have antibodies to both the human and the bacterial mimic. We now need to work out if the mimic of ubiquitin sets up the mistaken immune response. We may then be able diagnose some autoimmune diseases early and eventually be able to prevent some of the them from happening.

“We now want to see if we can make a rapid test that will tell us how much antibody people have so that we can quickly see any changes. We hope that this will allow early diagnosis of disease”

Professor Patrick added: “Our research could have far-reaching effects for other diseases, not just autoimmune disease. Ubiquitin is essential for our bodies to function normally. We have shown that a bacterium from the gut produces a very close molecular mimic of ubiquitin that gets into our system. It may not only cause the immune system to malfunction, but could be an underlying cause of other human conditions that we don’t yet fully understand.”

The next step for the research team is to find out the relationship between the stage of disease and antibody levels to the bacterial mimic in individual patients. This should help the development of a rapid test.


Explore further:
Team identifies potential cause for lupus

More information:
L. Stewart et al. Antigenic mimicry of ubiquitin by the gut bacterium Bacteroides fragilis : a potential link with autoimmune disease, Clinical & Experimental Immunology (2018). DOI: 10.1111/cei.13195

Provided by:
Queen’s University Belfast

Tagged with:

About author

Related Articles