Clinical research has long focused on ways to harness the actions of the immune system. From vaccines to immunotherapies, researchers have used their knowledge of the immune system to develop therapies to treat or prevent diseases from influenza to autoimmune disease and cancer.
Now, researchers from Penn’s School of Dental Medicine and international collaborators have investigated the effects of training the innate immune system in experimental models of two chronic inflammatory diseases, periodontitis and arthritis. They found that this “trained” immunity, or TRIM, led to increased bone loss in these models. This study is published in Developmental Cell.
Previous approaches have largely focused on the adaptive immune system, that branch of the immune system that “remembers” previous threats and launches specific attacks when it encounters them again. The body also has an innate immunity branch, which, for a long time, was just considered the first-line, general attack arm of the immune system with no ability to remember prior assaults or respond differently when rechallenged.
If you go and look at an immunology textbook-even today-it will likely tell you that innate immunity has no memory; its response doesn’t get improved the second time.”
George Hajishengallis, the Thomas W. Evans Centennial Professor in the Department of Basic & Translational Sciences at Penn Dental Medicine
This belief, Hajishengallis notes, has been challenged over the past decade. Studies have shown that the innate immune system can respond more strongly when challenged again with the same or different stimulus-in other words, it can be “trained.”