Breaking News
October 21, 2018 - Income and wealth affect the mental health of Australians, study shows
October 21, 2018 - Patients with hypertension and psoriasis more often require cardiovascular interventions
October 20, 2018 - Leading hip-hop videos depict use of tobacco and marijuana products, study finds
October 20, 2018 - Dose Range of IV Ketamine for Adjunct Tx of Depression Tested
October 20, 2018 - Infants can distinguish between leaders and bullies, study finds
October 20, 2018 - Mad Cow disease found on Aberdeenshire farm
October 20, 2018 - Study identifies factors associated with prescription opioid misuse among students
October 20, 2018 - Scientists uncover key regulator of mTORC1 in cancer growth
October 20, 2018 - Pounds Regained After Weight-Loss Op Can Tell Your Doc a Lot
October 20, 2018 - Sending parents letters to fight childhood obesity doesn’t work
October 20, 2018 - Supervised aerobic exercise can support major depression treatment
October 20, 2018 - Mindfulness-based program effective for reducing stress in infertile women
October 20, 2018 - Molecule capable of halting and reverting neurodegeneration caused by Parkinson’s disease identified
October 20, 2018 - Midazolam-mediated alterations of PER2 expression may have functional consequences during myocardial ischemia
October 20, 2018 - Sweat bees are ideal for studying the genes underlying social behavior
October 20, 2018 - Weight loss success associated with brain areas involved in self-control
October 20, 2018 - KHN’s ‘What the Health?’ Republicans’ preexisting political problem
October 20, 2018 - Research provides a more complete picture of suffering caused by terrorist attacks
October 20, 2018 - Eradicating Helicobacter pylori infections may be a key treatment for Parkinson’s disease
October 20, 2018 - Breast Cancer as a Dynamic Disease
October 20, 2018 - University of Pittsburgh wins NSF grant for big data research to prevent complications from anesthesia
October 20, 2018 - Skin-to-skin contact may promote attachment between parents and preterm infants
October 20, 2018 - Recommendations Developed to Verify NGT Placement in Children
October 20, 2018 - Weight loss can be boosted fivefold thanks to novel mental imagery technique
October 20, 2018 - Children with autism are more likely to be overweight, obese
October 20, 2018 - Nurses making conscientious objections to ethically-relevant policies lack support
October 20, 2018 - Prion strain diversity may be greater than previously thought
October 20, 2018 - Antidepressant treatment may lead to improvements in sleep quality of patients with depression
October 20, 2018 - Study reports increased risk of death in children with inflammatory bowel disease
October 20, 2018 - Number of Autism Genes Now Tops 100
October 20, 2018 - Total diet replacement programmes are effective for treating obesity
October 20, 2018 - CLARIOstar used for fluorescence measurements on CSIRO’s purpose-built research vessel
October 20, 2018 - People with more copies of AMY1 gene digest starchy carbohydrates faster
October 20, 2018 - Case Comprehensive Cancer Center wins NIH grant to study health disparities
October 20, 2018 - Newly discovered compound shows potential for treating Parkinson’s disease
October 20, 2018 - High rate of non-adherence to hormonal therapy found among premenopausal early breast cancer patients
October 20, 2018 - Immunotherapy medicine found to be effective in treating uveitis
October 20, 2018 - The Pistoia Alliance Calls for Greater Collaboration to Realise Benefits of Innovation and Announces Winners of the 2018 President’s Startup Challenge
October 20, 2018 - Female internists consistently earn less than men
October 20, 2018 - Stanford team looks at dangers of teens’ vaping habits
October 20, 2018 - New approach to understanding cancers will accelerate development of better treatments
October 20, 2018 - LJI and UC San Diego awarded $ 4.5 million as part of NCI’s Cancer Moonshot initiative
October 20, 2018 - School-based HPV vaccination did not increase risky sexual behaviors among adolescent girls
October 20, 2018 - Eye discovery to pave way for more successful corneal transplants
October 20, 2018 - New analysis examines the importance of location in the opioid crisis
October 20, 2018 - Green filters increase reading speed for children with dyslexia
October 19, 2018 - Bariatric Sx Cuts Macrovascular Complications in Obesity, T2DM
October 19, 2018 - Better assessments for early age-related macular degeneration
October 19, 2018 - Visible and valued: Stanford Medicine’s first-ever LGBTQ+ Forum | News Center
October 19, 2018 - Understanding of metal-free enzymes used by bacteria could lead to new effective antibiotics
October 19, 2018 - Beckman Coulter Life Sciences announces new research-focused website
October 19, 2018 - Study finds link between refined soluble fibers, gut microbiota and liver cancer
October 19, 2018 - Social media reduces risk of depression among seniors with pain
October 19, 2018 - Newly developed synthetic DNA molecule may one day be used as ‘vaccine’ for prostate cancer
October 19, 2018 - Preoperative weight loss may not provide health benefits after surgery
October 19, 2018 - U.S. Birth Rates Continue to Drop as Age of New Moms Rises
October 19, 2018 - New technology can keep an eye on babies’ movements in the womb
October 19, 2018 - Juul e-cigarettes pose addiction risk for young users | News Center
October 19, 2018 - Gene sequencing reveals crucial molecular aspects of Trypanosoma brucei
October 19, 2018 - New DNA vaccine strategy protects mice against lethal challenge by multiple H3N2 viruses
October 19, 2018 - Study shows close link between cytokine interleukin-1ß and obesity-promoted colon cancer
October 19, 2018 - Muscle mass plays a critical role in health, shows research
October 19, 2018 - Study finds undiagnosed prediabetes in many infertile men
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 - Study reveals impact of Juul use on teenagers and young adults
October 19, 2018 - Green leafy vegetables could help reduce macular degeneration risk
October 19, 2018 - Some countries take more time for reimbursement decisions on new cancer drugs
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
Scientists reveal active role of IgG antibodies in severity of anaphylaxis

Scientists reveal active role of IgG antibodies in severity of anaphylaxis

image_pdfDownload PDFimage_print

The most severe allergic reaction, anaphylaxis (or anaphylactic shock), is the result of an inappropriate immune reaction following the introduction of a usually harmless antigen into the body. The production of antibodies against this antigen (or allergen) allows the formation of antibody-antigen complexes that trigger a massive secretion of potent mediators, resulting in organ failure, which may lead to a state of shock and possibly death. While it was already known that IgE antibodies can trigger these allergic reactions, scientists from the Institut Pasteur, Inserm, the CNRS and EFS Grand Est recently demonstrated that IgG antibodies play an active role in the severity of anaphylactic shock by unexpectedly activating blood platelets.

Allergies are generally associated with the presence of IgE antibodies, which are responsible for activating specific cells in the immune system that secrete histamine, giving rise to clinical signs. But animal studies revealed that an alternative pathway depending on IgG-type antibodies exists. In this study, scientists from the Antibodies in Therapy and Pathology Unit (Institut Pasteur/Inserm U1222) revealed that platelets, whose best-known function is to stop bleeding when a blood vessel becomes damaged, play a key role in IgG-dependent anaphylactic reactions.

The role of blood platelets in anaphylaxis

To study the role of platelets in anaphylaxis, the scientists used transgenic mice expressing human receptors for IgG antibodies, since mice do not have these receptors on their platelets. Injecting these mice with human IgG antibodies triggered an anaphylactic reaction, characterized by a drop in body temperature and leading to a significant reduction in the circulating platelet count that lasted for several hours after the shock, suggesting that platelets might play a role in the allergic reaction. To confirm their function, the scientists eliminated the platelets from the blood, which led to a reduction in symptoms. Conversely, increasing the platelet count in the blood resulted in a much worse allergic reaction.

Molecules secreted by platelets may be behind the process

The scientists then carried out a more detailed analysis of the molecules secreted by platelets, which may be behind the process. Together with the French Blood Service (EFS) for the Grand Est region, based in Strasbourg (Inserm UMR_S1255), they tested the involvement of serotonin, already known to have an effect on vascular permeability. They demonstrated that serotonin, stored in platelets and released when they are activated, induces the drop in body temperature associated with anaphylaxis.

These observations, made in mice, were complemented by data from a multicenter clinical trial carried out by the “NASA” consortium and sponsored by Bichat Hospital (AP-HP). This trial monitored patients presenting with perioperative anaphylactic shock. Patient blood samples similarly seemed to contain fewer platelets and showed signs of activation during an episode of anaphylactic shock.

The lead author of the study, Friederike Jönsson, notes that “this work, which reveals the key function of platelets in anaphylactic shock, demonstrates the potential of exploring therapeutic interventions that target platelets as means of limiting the severity of anaphylactic shock, while also paving the way for improvements to diagnosis by characterizing the role of IgE and IgG antibodies.”

The scientists intend to continue their research by focusing more closely on the activation mechanisms of platelets during anaphylaxis.

Source:

https://www.pasteur.fr/en/research-journal/news/igg-antibodies-activate-blood-platelets-and-contribute-severity-anaphylaxis

About author

Related Articles