Studies in mice show that social stress alters the response of a key immune cell in a way that could damage health under certain conditions.
The research appears in a recent issue of the American Journal of Physiology - Regulatory Integrative and Comparative Physiology.
During a normal immune response, the immune system sends out pro-inflammatory cells. These cells go to sites of tissue damage, whether it's an open wound or a bacterial or viral infection. The cells contribute to the inflammatory response. Inflammation helps control infection and plays a key role in the early phase of wound healing.
Corticosterone, an anti-inflammatory hormone, regulates the intensity of the pro-inflammatory response. Corticosterone is one of a group of anti-inflammatory hormones known as glucocorticoids.
Ohio State University researchers have found that social stress makes specific immune cells, called macrophages, corticosterone-resistant. Macrophages are pro-inflammatory immune cells that play multiple roles in the immune system.
The result is that inflammation runs out of control, increasing the severity of infection and causing damage to tissues and organs.
"Corticosterone resistance may work well to help heal skin wounds, such as bites," said John Sheridan, a study co-author and a professor of oral biology and molecular virology at Ohio State University. "But resistance may harm an animal with an autoimmune disease or ongoing infection."
The results have implications for human health.
Glucocorticoids are often used to treat patients with inflammatory diseases such as asthma, rheumatoid arthritis and leukemia. But some people develop resistance to these hormones, particularly patients with severe depression and those infected with HIV.
This research was supported by grants from the National Institutes of Mental Health and by the John D. and Catherine T. MacArthur Foundation.
Sheridan co-authored the study with Ohio State researchers Jennifer Stark; Ronit Avitsur; David Padgett; Kim Campbell; and F. Michael Beck.
Contact: John Sheridan, 614-292-2012; Sheridan.1@osu.edu
Written by Holly Wagner, 614-292-8310;
Wagner.235@osu.edu