SCI adv: mechanism of side effects in patients with autoimmune diseases

December 18, 2019 / Bio Valley bio on / -- rheumatoid arthritis, psoriasis, Crohn's disease and other autoimmune diseases afflict most groups in the world Fortunately, there are several new drugs for these diseases However, the use of these drugs, known as TNF inhibitors, is associated with the risk of serious infection and even cancer Recently, a team at the University of Michigan Medical school may have found out the cause of side effects caused by TNF-a inhibitors The results, published in the journal Science advance, reveal previously unknown functions of dendritic cells (image source: www Pixabay Com) dendritic cells are part of the innate immune network and the first line of defense against threats They help another immune cell, known as a T cell, an adaptive immune system, learn how to respond appropriately to a given bacterium or pathogen "Dendritic cells are the main coordinator of the immune response, and they tell other cells in the immune system what to do," explains Michal Olszewski, an associate professor and author of the article This study shows that these cells have their own form of programmed memory and rely on TNFa molecules "Our study found that TNFa is part of a system that programs dendritic cells, so they know how to program T cells," Olszewski said TNFa is particularly important in helping dendritic cells guide T cells against certain fungal and tuberculosis infections that are hidden in cells in the body That's why people taking these autoimmune drugs are particularly vulnerable to these infections "Some microbes are very smart, they fool the immune system, escape killing, and cause disease In our study, we found that microorganisms could not play these roles in the presence of TNFa In addition, the team found that the programming of dendritic cells depended on rapid changes in epigenetics This finding is of great significance for the development of therapies for the immune system "It's important for vaccine development to understand how the immune system responds to chronic infections and why patients taking anti TNF therapy for autoimmune diseases are particularly vulnerable to these diseases," Olszewski said Information source: the danger behind certain biology original source: Alison J Eastman, Jintao Xu, Jennifer bermik, Nicole potchen, Aaron den Dekker, Lori M Neal, Gulei Zhao, Antoni malachowski, Matt Schaller, Steven Kunkel, John J osterholzer, Ilona kryczek, Michal A Olszewski Epigenetic stabilization of DC and DC precursor classical activation by TNFα contributes to protective T cell polarization Science Advances , 2019; 5 (12): eaaw9051 DOI: 10.1126/sciadv.aaw9051