Early warnings from the immune system inspire new remedies

September 20, 2022 – The immune system is among the most complex and mysterious in the human body and is more multifaceted than previously thought, report researchers in the burgeoning field of mechanoimmunology, who track how our bodies fight disease and successfully counteract it.

Unlike other systems that rely on organs, the immune system uses millions of different specialized cells to scour every corner of the body for invaders and dispatch them when necessary. It also relies heavily on the microbiome, the busy communities of bacteria that perform many of our essential functions, despite not actually being our own body cells.

Scientists are learning more and more about how the immune system works every day, and now researchers at the Buck Institute for Research on Aging in Novato, California, have begun to uncover how physical — and not just chemical — forces in the cellular environment also play a role Role play an important role in immune functions.

It has already been established that mechanical activity plays a role in other body systems, particularly the cardiovascular and skeletal systems. Deposits in the arteries of the heart can reduce blood flow, too much pressure on bones can cause stress fractures, and pressure on tissues can cause scarring.

The idea that physical properties, and not just chemical reactions, have a significant impact on immune function is a new idea that is just beginning to garner attention. Dan Winer, MD, associate professor at the Buck Institute, discovered in his study of obesity that an increase in adipose tissue activates fibrosis — thickened scar tissue — which then prompts surrounding cells to become aware of potential threats to the body, and chronic ones to respond illness.

Now his lab is expanding his focus to mechanoimmunology to explore how physical forces affect autoimmunity, the increase or decrease in inflammation, and the ability to heal after tissue injury.

Expanding scientists’ understanding of these forces will open the door to new therapies to treat disease – approaches that rely on altering the physical microenvironment of tissues, rather than delivering drugs to trigger chemical reactions. For example, cirrhosis, scarring of the liver, affects tissue that is much stiffer than surrounding healthy liver tissue. If researchers can develop a treatment that reduces this stiffness, neighboring immune cells could slow down their inflammatory response in the liver, which could have a positive impact on fatty liver disease. Other applications of this concept could address how therapeutics respond to infection or help speed healing