A role for immune cells in wound regeneration
Immune cells involved in muscle healing following implantation of biomaterial scaffold
Researchers from Johns Hopkins and the Kennedy Krieger Institute (both MD, USA) have observed immune system cells to direct healing of mouse muscle wounds when paired with biologic scaffolding for support. The findings add to growing evidence that the immune system is key to initiating healing after injury, and can be aided by biomaterial scaffolds designed to partner it.
"In previous research, we've seen different immune system responses to the same biomaterial implanted in different tissues or environments, and that got us interested in how biomaterials might stimulate the immune system to promote regeneration," explained last author Jennifer Elisseeff (Johns Hopkins University School of Medicine). "We still have a lot to learn, but this study is a step toward designing materials to elicit a beneficial immune response."
In this study, researchers surgically removed thigh muscle from mice and implanted scaffolds known to promote healing in animals. After one week, wound sites with scaffolds were observed to have more white blood cells than wounds without scaffolds. Many of the white cells were found to be producing interleukin-4, frequently produced by type 2 helper T cells. When the procedure was repeated in mice genetically modified to lack T cells, increased interleukin production was not observed and healing was impaired versus normal mice. Further investigation suggested that the type 2 helper T cells were both activating and training macrophages at the wound site.
It is clear from these findings that we still have much to learn about how immune cells respond to the biomaterials used in scaffolds and their potential exploitation in wound healing – an area the team will continue to investigate.
Written by Hannah Wilson
Source: EurekAlert press release www.eurekalert.org/pub_releases/2016-04/jhm-ttc041316.php