September 20, 2022 – The immune system is one of the most complex and mysterious in the human body, and it is more versatile than previously thought, report researchers in the emerging field of mechanoimmunology, following how our body fights disease and how to successfully intervene.
Unlike other systems that rely on organs to function, the immune system uses millions of different specialized cells to patrol every corner of the body looking for invaders and dispatching them as needed. It also relies heavily on the microbiome, the thriving communities of bacteria that perform many of our essential functions, even if they aren’t actually our own body cells.
Scientists are learning more every day about how immune system works, and now researchers at the Buck Institute for Research on Aging in Novato, Calif., have begun to uncover how physical — rather than just chemical — forces in the cellular environment also play a vital role in immune function.
Mechanical activity has previously been thought to play a role in other body systems, particularly the cardiovascular and skeletal systems. Accumulation in arteries of the heart can decrease blood flow, excessive pressure on bones can cause stress fractures, and pressure on tissues can cause scarring.
The idea that physical properties, rather than just chemical reactions, have a significant impact on immune function is a new idea that’s only just beginning to attract attention. Dan WinnerMD, an associate professor at the Buck Institute, found in his study of obesity which increases adipose tissue activates fibrosis – thickened scar tissue – which then triggers surrounding cells to stay alert to potential threats to the body and respond to chronic illnesses.
Today, his lab focuses on mechanoimmunology to discover how physical forces impact autoimmunity, increasing or decreasing inflammation and healing forces after tissue injury.
Expanding scientists’ understanding of these forces will open the door to new therapies for treating disease – approaches that rely on altering the physical microenvironment of tissues rather than administering drugs to induce chemical reactions. For example, cirrhosis, a scarring of the liver, involves much stiffer tissue than the surrounding healthy liver tissue. If researchers can develop a treatment that reduces this stiffness, nearby immune cells could slow their inflammatory response in the liver, which could have a positive impact on fatty liver. Other applications of this concept could address how therapeutics respond to infections or help speed healing.