The work could lead to new immunotherapy treatments. The immune system fights bacteria, viruses, and other pathogens by utilizing several types of T cells, all of which have receptors that are specific to particular antigens. On killer T cells, the receptor works in concert with three signaling modules and a coreceptor to destroy the infected cell. “When we saw that the 5MCAR T cells completely eliminated the harmful T cells that invaded the pancreas, we were blown away.” The researchers copied the evolutionary design to engineer a five-module chimeric antigen receptor, or 5MCAR, T cell. “The 5MCAR was an attempt to figure out if we could build something by biomimicry, using some of evolution’s natural pieces, and redirect T cells to do what we want them to do. We engineered a 5MCAR that would direct killer T cells to target autoimmune T cells that mediate type 1 diabetes,” says Michael Kuhns, an associate professor in the immunobiology department at the University of Arizona College of Medicine-Tucson, who is a member of the university’s Cancer Center, the BIO5 Institute, and the Arizona Center on Aging.