Breaking News
October 19, 2018 - The Current issue of “The view from here” is concerned with Nanotherapeutic strategies
October 19, 2018 - Delay in replacing the Pap smear with HPV screening is costing lives
October 19, 2018 - Physicians battle pediatric diseases of ear, nose, throat in Zimbabwe | News Center
October 19, 2018 - Researchers investigate why some cancers affect only young women
October 19, 2018 - Drugmakers funnel millions to lawmakers; a few dozen get $100,000-plus
October 19, 2018 - Unselfish people tend to have more children and receive higher salaries
October 19, 2018 - New findings reveal potential cellular players in tumor microenvironment
October 19, 2018 - Human brain cell transplant offers insights into neurological conditions
October 19, 2018 - Parental education associated with increased family health care spending
October 19, 2018 - New statistical method estimates long- and short-term risk of recurrence of breast cancer in US women
October 19, 2018 - Father’s exposure to nicotine may cause cognitive deficits in descendants
October 19, 2018 - Could we prevent Alzheimer’s disease by treating herpes?
October 19, 2018 - Nurse-led care can be more successful in managing gout
October 19, 2018 - Trump administration, pharma exchange verbal volleys on drug-price transparency
October 19, 2018 - Duke researchers find way to detect blood doping in athletes
October 19, 2018 - Many primary care doctors are still prescribing sedative drugs for older adults
October 19, 2018 - Finger length can predict sexuality in women say researchers
October 19, 2018 - Study finds differences in side-effects experienced by male and female OG cancer patients
October 19, 2018 - Few Seniors Who Self-Harm Referred for Mental Health Care
October 19, 2018 - Don’t sweat the sweet stuff
October 19, 2018 - URMC researchers discover new approach to deliver therapeutics to the brain
October 19, 2018 - Middlemen suppliers can increase drug prices and hospital bills, say Johns Hopkins researchers
October 19, 2018 - Human neurons employ highly compartmentalized signaling, study shows
October 19, 2018 - Ultromics expands multiple clinical trials for coronary heart disease to the U.S.
October 19, 2018 - $11 million NIH grant for Clemson University helps launch new center for musculoskeletal research
October 19, 2018 - A new approach identified to control Zika virus, dengue fever
October 19, 2018 - Head Blows Without Concussion May Not Damage Brain, Study Claims
October 19, 2018 - US opioid use not declined, despite focus on abuse and awareness of risk
October 19, 2018 - Next-generation RNA sequencing technology sheds new light on human mitochondrial diseases
October 19, 2018 - UT Southwestern biochemist receives 2019 Breakthrough Prize in Life Sciences for innate immunity discovery
October 19, 2018 - The immune system also plays a key role in day-to-day function of healthy organs
October 19, 2018 - New tool may reveal how the brain structure impacts brain activity, human behavior
October 19, 2018 - Trump Administration announces ‘Winning on Reducing Food Waste’ initiative
October 19, 2018 - For-profit nursing home residents more likely to experience health issues caused by substandard care
October 19, 2018 - Incidence of stroke has risen steadily among marijuana users, show studies
October 19, 2018 - Conceptual framework proposed to examine role of exercise in multiple sclerosis
October 19, 2018 - Near infrared spectroscopy technique for accurate evaluation of chondral injuries
October 19, 2018 - Scientists receive $5.1 million grant to develop stem cell-based therapy for blinding retinal conditions
October 19, 2018 - Shorter physician encounters associated with antibiotic prescribing
October 19, 2018 - In the Spotlight: Enjoying research and exploring opportunities
October 19, 2018 - Physical activity lowers cardiovascular mortality risk in frail older adults
October 19, 2018 - New imaging tool helps visualize how sound-induced vibrations travel through the ear
October 19, 2018 - Key insights into the application, production of bioactive materials
October 19, 2018 - New urea sorbent could speed up the development of wearable artificial kidney
October 19, 2018 - Intensive care patients’ muscles less able to use fats for energy
October 19, 2018 - FDA Advisory Committee Recommends Approval of Dsuvia for the Treatment of Moderate-to-Severe Acute Pain
October 19, 2018 - 48,XXXY syndrome – Genetics Home Reference
October 19, 2018 - Physical exercise improves the elimination of toxic proteins from muscles
October 19, 2018 - How a new system improved wait times for Stanford kidney transplant patients
October 19, 2018 - Nutrition has bigger positive impact on bone mass and strength than exercise
October 19, 2018 - Study finds lack of progress in media representation of nurses over last 20 years
October 19, 2018 - Many people have trouble understanding differences between OCD and OCPD
October 19, 2018 - New family planning app found to be as effective as modern methods
October 19, 2018 - Gastric Banding, Metformin Similar for Improving Glycemia
October 19, 2018 - Physiologist publishes findings on the role of the protein titin in muscle contraction
October 19, 2018 - What digital health companies need to do to succeed
October 19, 2018 - N. Carolina Sees Alarming Spike in Heart Infections Among Opioid Users
October 19, 2018 - Video monitoring of TB therapy works well in urban and rural areas
October 19, 2018 - Determining acid-neutralizing capacity for OTC antacids
October 19, 2018 - Males who spend more time taking care of kids have greater reproductive success
October 18, 2018 - Study to explore bioethics of brain organoids
October 18, 2018 - Environmental conditions may drive development of multiple sclerosis
October 18, 2018 - Genetically modifying zebrafish provides more accurate disease models
October 18, 2018 - Purdue Pharma, Eisai announce positive topline results from Phase 3 study of lemborexant
October 18, 2018 - 5 Strength-Training Mistakes to Avoid
October 18, 2018 - Immune system’s balancing act keeps bowel disease in check
October 18, 2018 - Anti-inflammatory drug effective for treating lymphedema symptoms | News Center
October 18, 2018 - Keeping Your Voice Young
October 18, 2018 - One-time universal screening recommended to tackle increase in hepatitis C
October 18, 2018 - Researchers to develop new stem cell-based strategies for treating vision disorders
October 18, 2018 - Detecting epigenetic signature may help people stay ahead of inflammatory bowel disease
October 18, 2018 - Understanding AFib: Slowing down the dancing heart
October 18, 2018 - Using NMR to Reduce Fraud
October 18, 2018 - New automated model identifies dense breast tissue in mammograms
October 18, 2018 - Mysterious polio-like illness baffles medical experts while frightening parents
October 18, 2018 - Cases of Acute Flaccid Myelitis on the rise across U.S.
October 18, 2018 - Dietary fiber reduces brain inflammation during aging
October 18, 2018 - New tool could help prioritize recovery efforts for the poorest hit by natural disasters
October 18, 2018 - Hundreds of dietary supplements shown to contain unapproved drugs
October 18, 2018 - Active Pharmaceuticals ID’d in >700 Dietary Supplements
New warning system discovered in the immune defence

New warning system discovered in the immune defence

image_pdfDownload PDFimage_print
Visualization of extracellular DNA in cell culture medium after treatment of CLL B cells with CpG-C. Credit: Reproduced with permission from Proceedings of the National Academy of Sciences

Researchers at Linköping University in Sweden have discovered a previously unknown warning system that contributes to the body’s immune system. Mitochondria in the white blood cells secrete a web of DNA fibres that raises the alarm. The results have been published in the scientific journal PNAS, and may lead to increased knowledge about autoinflammatory diseases and cancer.

White blood cells are major components of the body’s immune defence, and the research group has shown that several types of these cells react against small DNA fragments that are similar to the DNA from bacteria and viruses. The white blood cells spray out a web consisting of mitochondrial DNA (mtDNA) strands. Mitochondria are present in all cells and normally produce the energy needed by the cell, by burning sugar and fat to form water and carbon dioxide.

The web that the mitochondria release sends signals to the surrounding cells that the body is under attack, and cause other white blood cells to release a signal substance known as interferon type 1. This substance helps the immune system to combat the infection. Previous studies have shown that the level of mtDNA in the blood can be elevated after certain inflammatory diseases and after some surgical traumas.

“We show that the white blood cells in the immune system can release mtDNA outside the cells in an active process in response to infectious agents such as bacteria and viruses. The discovery raises the possibility of further studies in which we will try to reduce the release of mtDNA, and in this way reduce the inflammation that it causes,” explains Björn Ingelsson, researcher and associate lecturer at the Department of Clinical and Experimental Medicine at Linköping University. He has conducted the research together with Professor Emeritus Anders Rosén and other co-workers.

Other types of web formed by white blood cells in the immune system (neutrophils) were previously known. These cells release meshes coated with antibacterial proteins. However, the formation of the newly discovered mtDNA webs differs fundamentally from that of the other types of web. The researchers have shown that the mtDNA webs are activated within a couple of minutes, which is faster than the neutrophil-based meshes. The latter also lack the signal function that the mtDNA webs have. Further, the mtDNA webs survive in the blood longer before being dissolved.

Is this a positive process in which the immune defence works to remove the intruding bacteria or viruses? “Well, of course it’s positive that the defence mechanisms are activated. But remember that you can have too much of a good thing. If an unintentional secretion of mtDNA occurs, or if the secreted mtDNA is not removed from the blood, undesired inflammation may occur, and it is this side-effect we want to prevent,” says Björn Ingelsson.

High levels of interferon type 1, the signal substance activated by the mtDNA webs, occur in several autoimmune diseases and several types of cancer. The researchers believe that it may be possible to quantify the secreted mtDNA molecules and interpret the warning signals, and in this way understand these diseases better.


Explore further:
First DNA sequence from a single mitochondria

More information:
Björn Ingelsson et al, Lymphocytes eject interferogenic mitochondrial DNA webs in response to CpG and non-CpG oligodeoxynucleotides of class C, Proceedings of the National Academy of Sciences (2018). DOI: 10.1073/pnas.1711950115

Journal reference:
Proceedings of the National Academy of Sciences

Provided by:
Linköping University

Tagged with:

About author

Related Articles