Breaking News
March 26, 2019 - DermBiont Begins Phase 2 Clinical Trial for Athlete’s Foot with a Live Bacterial Topical Probiotic
March 26, 2019 - Persons with Alzheimer’s disease have a higher risk of head injuries
March 26, 2019 - Mental health issues associated with income inequalities in Indigenous people
March 26, 2019 - Participation in sports linked with fewer depressive symptoms in children
March 26, 2019 - Brain process common to sleep and aging discovered
March 26, 2019 - People under age 50 with hearing loss more likely to misuse alcohol and drugs
March 26, 2019 - People with and without cancer use different dosages of cannabis formulations, study shows
March 26, 2019 - Young people at risk of addiction show differences in key brain region
March 26, 2019 - In virtual exchange, students in California and Lebanon unite to improve refugee health
March 26, 2019 - Trump Administration Changes Course, Asks Court To Strike Down ACA
March 26, 2019 - People with untreated diabetes develop signs of Alzheimer’s disease at a faster rate
March 26, 2019 - Study explains how bright colors evolved and diversified in male guppies
March 26, 2019 - Savings from lower insurance costs of growth hormone drugs not passed on to patients
March 26, 2019 - Study highlights the need to pay more attention on specific nutritional needs of female athletes
March 26, 2019 - Sleep quality varies throughout menstrual cycle in young women
March 26, 2019 - Younger Female Blood Donors Vulnerable to Iron Deficiency
March 26, 2019 - Finding the elusive drinking ‘brake’
March 26, 2019 - Using the Mastermind strategy in brain research
March 26, 2019 - Symptomatic pharmacotherapy of elderly people should be regularly monitored
March 26, 2019 - Synthetic biological logic gate could one day be used to modify cellular function
March 26, 2019 - Damage to anxiety-associated brain region heightens monkeys’ defensive response
March 26, 2019 - Researchers uncover large-scale brain patterns and networks which control sleep
March 26, 2019 - Scientific Symposium at LABVOLUTION focuses on key issues in life sciences
March 26, 2019 - Screen time plus snacking could increase risk for metabolic syndrome in teens
March 26, 2019 - Attention, Seniors: Drink More Water and Head Off Disease
March 26, 2019 - Peptide shows promise for protecting kidneys from nephritis
March 26, 2019 - Causes of diabetes decline or disappear when ‘zombie cells’ are removed, shows study
March 26, 2019 - Scientists identify common genetic variants associated with post-stroke recovery
March 26, 2019 - Study finds link between menopause and changes in body composition
March 26, 2019 - Higher levels of sex hormones in older men related to lower biological age
March 26, 2019 - Research links participation in team sports to larger hippocampal volumes in children
March 26, 2019 - Cerveau announces research collaboration agreement with Eisai for novel tau imaging agent
March 26, 2019 - New technique measures frequency of sounds emitted from biological structures
March 26, 2019 - Removal of ‘zombie cells’ alleviates causes of diabetes in obese mice
March 26, 2019 - Women exposed to deepwater horizon oil spill continue to experience PTSD symptoms
March 26, 2019 - Shaping new treatments for tuberculosis
March 26, 2019 - Understanding genetic interactions holds key to new personalized therapies
March 26, 2019 - Nervous system relies on guidance cues for neuronal axons to reach destinations
March 26, 2019 - Altering gut microbiome may be potential treatment option for PCOS
March 26, 2019 - Moleculin Files with FDA for Expedited Approval Pathway for Annamycin
March 26, 2019 - GPs play pivotal role in ensuring success of new Faster Diagnosis Standard for Cancer
March 26, 2019 - New clues discovered to lung transplant rejection
March 26, 2019 - New study offers insight into development of delusions
March 26, 2019 - Children’s ball pits full of pathogenic microbes
March 26, 2019 - Exploring pathophysiological factors that link sleep problems and Alzheimer’s disease
March 26, 2019 - Walking downhill after meals can reduce bone resorption in postmenopausal women with diabetes
March 26, 2019 - USA LESS Issues Voluntary Nationwide Recall of LEOPARD Miracle Honey Due to Presence of Undeclared Sildenafil
March 26, 2019 - CT scan prior to spine fusion finds almost half of patients had undiagnosed osteoporosis
March 26, 2019 - After 2 Apparent Student Suicides, Parkland Grieves Again
March 25, 2019 - Inherited form of rickets improves more with new injectable medicine than conventional therapy
March 25, 2019 - Trastuzumab Tied to Higher Long-Term Risk for Heart Failure
March 25, 2019 - Personal context directly affects CPAP use
March 25, 2019 - Mosquito tracking key to preventing disease outbreaks
March 25, 2019 - Scientists Detect Hidden Signals from Beneficial Bacteria
March 25, 2019 - Treating women with thyroid antibodies with Levothyroxine do not increase live birth rate
March 25, 2019 - Brain area that only processes spoken, not written words identified
March 25, 2019 - Race and ethnicity influence fracture risk in diabetic patients
March 25, 2019 - Researchers report new regenerative medicine approach for treating osteoarthritis of the knee
March 25, 2019 - Exposure to dim light at night may contribute to spread of breast cancer to bones
March 25, 2019 - Benefits of osteoporosis treatment in postmenopausal women outweigh the perceived risks
March 25, 2019 - Researchers find evidence of Cryptosporidium parasite in Minnesota’s public water systems
March 25, 2019 - Three Clues to Raised Risk of Miscarriage
March 25, 2019 - Structured play helps toddlers self-regulate, altering their life course
March 25, 2019 - Translating horror into justice: Stanford psychiatrist advocates for human rights
March 25, 2019 - HORIBA Medical introduces D-Dimer reagent for Yumizen G hemostasis range
March 25, 2019 - Recurrent pregnancy loss may be caused by sperm DNA damage, finds study
March 25, 2019 - Special Collection tracks development of new diagnostic tests for tuberculosis
March 25, 2019 - Air Force develops genetic test to predict mental performance
March 25, 2019 - To abort or not to abort—making difficult choices alone
March 25, 2019 - Computer vision technology could aid ICU care by spotting movement
March 25, 2019 - IONTAS wins ‘Small Business of the Year’ category at Cambridge News Business Excellence Awards 2019
March 25, 2019 - First postpartum depression drug gets FDA nod
March 25, 2019 - Research Recognition Award will help improve lives of young people with absence epilepsy
March 25, 2019 - Bisphosphonates to treat osteoporosis appears to be beneficial for all women
March 25, 2019 - Time-restricted eating may prove to be a dietary intervention against breast cancer
March 25, 2019 - Researchers develop new augmented reality app to assess spatial memory
March 25, 2019 - Dolomite Bio releases new Drop-seq datasets for single-cell RNA sequencing
March 25, 2019 - Hemoglobin A1c blood test may underestimate prevalence of diabetes
March 25, 2019 - Immune system errors linked to development of childhood leukemia
March 25, 2019 - Eating leafy green vegetables may help maintain muscle strength and mobility
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