Breaking News
November 16, 2018 - High school students less likely to select milk, fruit for lunch when fruit juice is available
November 16, 2018 - Football coaches with great emotional competence are more successful
November 16, 2018 - Researchers awarded $10 million grant to address root causes of asthma in Puerto Rico
November 16, 2018 - Health Tip: Manage Morning Sickness
November 16, 2018 - Immunotherapy combination and chemotherapy show encouraging results in Phase II acute myeloid leukemia study
November 16, 2018 - ACC Latin America Conference brings experts to discuss latest cardiovascular science
November 16, 2018 - Pooled analysis of Intersect ENT’s steroid releasing implants in patients after frontal sinus surgery to be published
November 16, 2018 - Expectations about pain intensity can become self-fulfilling prophecies
November 16, 2018 - NIH awards $3.4 million to UC researchers to study gastrointestinal lymphatic system
November 16, 2018 - Scientist Dr David Taylor of MR Solutions is a finalist in the BMW i UK Tech Founder Awards
November 16, 2018 - Earlier treatment could help reverse autistic-like behavior in tuberous sclerosis
November 16, 2018 - Vegetables and salad may include bacteria that are resistant to antibiotics
November 16, 2018 - Endocrine Society chooses four Diabetes Caucus leaders as winners of Diabetes Champion Award
November 16, 2018 - Brain and muscle cells found within kidney organoids
November 16, 2018 - Person’s sex hormones may play key role in trauma survival, finds study
November 16, 2018 - PTEN Genetic Test: MedlinePlus Lab Test Information
November 16, 2018 - Toxic metal pollution linked with development of autism spectrum disorder
November 16, 2018 - Calcified nodules in the retina increase risk for progression to late stages of AMD
November 16, 2018 - ZEISS teams up with arivis AG to offer complete 3D imaging solutions
November 16, 2018 - Georgia State professor receives $1.2 million grant to study how the brain controls eating behavior
November 16, 2018 - Specific bacterial toxins reduce number of cells suppressing immune response
November 16, 2018 - Review by ID physician improves outcomes for outpatient parenteral antimicrobial therapy
November 16, 2018 - Conditions that produce signs similar to arthritis
November 16, 2018 - New artificial intelligence-based method predicts treatment effectiveness
November 16, 2018 - AHA: Dapagliflozin Noninferior to Placebo for MACE in T2DM
November 16, 2018 - Surgery remains best treatment for appendicitis, Stanford study finds
November 16, 2018 - Non-surgical fistula creation system Ellipsys becomes key focus of attention at CiDA
November 16, 2018 - Researchers find no link between ‘allergy friendly’ dogs and lower risk of asthma
November 16, 2018 - Researchers elucidate new rules of connectivity of neurons in the neocortex
November 16, 2018 - Treating children with ‘bubble baby disease’
November 16, 2018 - Nexus announces availability of Arsenic Trioxide Injection in the US
November 16, 2018 - Researchers find metabolite shuttle between cells in the liver that may combat tissue fibrosis
November 16, 2018 - AHA: PTSD Common Among Those Who Suffer Tear in the Aorta’s Wall
November 16, 2018 - Many RA patients’ pain related to central nervous system
November 16, 2018 - Changes in Himalayan gut microbiomes linked to diet
November 16, 2018 - Inhibition of prostaglandin E2 enhances ability to combat infectious colitis
November 16, 2018 - Chronic dry eye can slow reading rate and disrupt day to day tasks
November 16, 2018 - Researchers develop new drug molecule that inhibits inflammation
November 16, 2018 - Dementia symptoms peak in winter and spring, study finds
November 16, 2018 - Stanford tobacco researcher weighs in on JUUL
November 16, 2018 - Increasing omega-3 fatty acid intake during pregnancy reduces risk of premature birth, review finds
November 16, 2018 - Researchers find no link between infants waking up at night and later developmental problems
November 16, 2018 - Both parents and children agree about confidential medical services
November 16, 2018 - FDA warns against use of unapproved pain medications with implanted pumps
November 16, 2018 - Precision medicine-based approach to slow or reverse biologic drivers of Alzheimer’s disease
November 16, 2018 - Study provides new insight into norovirus outbreaks, may help guide efforts to develop vaccines
November 16, 2018 - Inexpensive, portable air purifier could help protect the heart from pollution
November 16, 2018 - New 15-minute scan could help diagnose brain damage in babies up to two years old
November 16, 2018 - Deep brain stimulation not effective for treating early Alzheimer’s
November 16, 2018 - Traditional chemotherapy superior to new alternative for oropharyngeal cancers | News Center
November 16, 2018 - What This Pond Protist Does With Its Genome Will Astound You
November 15, 2018 - Researchers develop tool that speeds up analysis and publication of biomedical data
November 15, 2018 - Scientists identify mechanism used by lung cancer cells to obtain glucose
November 15, 2018 - Abnormalities in development of the brain could be involved in onset of autism, finds new study
November 15, 2018 - Soy protein equally effective as animal protein in building muscle strength
November 15, 2018 - American Academy of Pediatrics, Nov. 2-6
November 15, 2018 - Dopamine drives early addiction to heroin
November 15, 2018 - Variance in gut microbiome in Himalayan populations linked to dietary lifestyle | News Center
November 15, 2018 - Reducing Cardiovascular Disease: The Amish Way
November 15, 2018 - King’s researchers launch charter to guide organizations to engage abuse survivors in research
November 15, 2018 - Enable Injections enters into development agreements with UCB and Apellis Pharmaceuticals
November 15, 2018 - TGen North collaborates with NARBHA Institute to advance human health
November 15, 2018 - Researchers discover molecular basis for therapeutic actions of an African folk medicine
November 15, 2018 - Human Cell Atlas study of early pregnancy shows how mother’s immune system is modified
November 15, 2018 - New guidelines for detecting and managing sarcopenia to be launched in the UK
November 15, 2018 - Researchers explore role of dietary composition on energy expenditure
November 15, 2018 - Elsevier launches Entellect™ Platform, unlocking value by creating AI-ready life sciences data
November 15, 2018 - Now that cannabis is legal in Canada, let’s use it to tackle the opioid crisis
November 15, 2018 - In the Spotlight: At the intersection of tech, health, and ethics
November 15, 2018 - Traditional Glaucoma Test Can Miss Severity of the Disease
November 15, 2018 - Researchers directly connect activities of genes with instinctive behavior in male cichlids
November 15, 2018 - Salk researchers report new methods to identify AD drug candidates with anti-aging properties
November 15, 2018 - St. Jude Hospital announces availability of largest collections of leukemia samples
November 15, 2018 - Attenua Announces First Patient Treated in Phase 2 Clinical Trial in Chronic Cough with Bradanicline
November 15, 2018 - Designing a novel cell-permeable peptide chimera to promote wound healing
November 15, 2018 - NEI investigators combine two imaging modalities to view the retina in unprecedented detail
November 15, 2018 - Determining how hearts develop to better understand congenital heart defects
November 15, 2018 - Maverick immune cells can act independently to identify and kill cancer cells, finds research
November 15, 2018 - Advanced AI and big data methods to tackle dementia
November 15, 2018 - Report reveals increase in pancreatic cancer death rates across Europe
Effect of gut bacteria on specific immune cells underlies persistent liver inflammation

Effect of gut bacteria on specific immune cells underlies persistent liver inflammation

image_pdfDownload PDFimage_print

Persistent liver inflammation in sufferers of chronic viral hepatitis is likely caused by interactions between pro-inflammatory immune cells in the liver and products from gut bacteria, according to new work involving A*STAR researchers. The findings identify new therapeutic targets.

Chronic viral hepatitis is characterized by persistent inflammation of the liver, but the mechanism that maintains this inflammation has been poorly understood. The degree of inflammation does not correspond to the extent of viral activity in the liver, or to the activity of immune cells that specifically target the virus, as might be expected.

The new work, a collaboration between the laboratories of Antonio Bertoletti at the Duke-NUS Medical and Singapore Institute of Clinical Sciences, the laboratory of Qingfeng Chen at the A*STAR Institute of Molecular and Cell Biology and Charles-Antoine Dutertre in the laboratory of Florent Ginhoux from the A*STAR Singapore Immunology Network, aimed to determine the mechanisms underpinning the inflammation. The researchers focused on a different group of immune cells called macrophages, which are increasingly recognized as significant in liver disease.

They analyzed the molecular and functional profiles of macrophages in the livers of patients with chronic viral hepatitis and those of healthy people. In the livers of patients, there was an excess of macrophages with a specific profile that promotes inflammation. “Unlike macrophages found in a healthy liver, these macrophages have the capacity to continuously produce pro-inflammatory mediators when they encounter bacterial products,” explains Dutertre.

The team studied this phenomenon further in mice engineered to have human liver cells and human immune cells. The mice were infected with hepatitis B virus, and consequently accumulated the same pro-inflammatory macrophage population in the liver as that seen in patients. Treatment of the mice with antibiotics to reduce the gut bacteria reversed the accumulation of these macrophages. “This demonstrated that bacterial products that leak from the gut into the liver are responsible for the accumulation of the pro-inflammatory macrophages,” says Dutertre.

The results identify a novel mechanism that maintains inflammation in chronic viral hepatitis. Dutertre and colleagues say that their findings suggest new therapeutic approaches, in addition to targeting the virus, that involve modifying the intestinal bacteria or depleting the pro-inflammatory macrophages in the liver.

The researchers are now investigating the mechanism behind the effects of bacterial products on macrophages in the liver. So far they have identified certain soluble mediators that play a pivotal role. “Our hypothesis is that by inhibiting these soluble mediators, we could limit the accumulation of the pro-inflammatory macrophages and resolve liver inflammation in patients with chronic viral hepatitis,” concludes Dutertre.


Explore further:
Zinc may hold key to fighting liver disease

More information:
Alfonso Tan-Garcia et al. Intrahepatic CD206 + macrophages contribute to inflammation in advanced viral-related liver disease, Journal of Hepatology (2017). DOI: 10.1016/j.jhep.2017.04.023

Provided by:
Agency for Science, Technology and Research (A*STAR), Singapore

Tagged with:

About author

Related Articles