Cellular therapies based on permanent genetic modification of conventional T cells have emerged as a promising strategy for cancer. However, it remains unknown if modification of T cell subsets, such as Tregs, could be useful in other settings, such as allograft transplantation. Here, we use a modular system based on a chimeric antigen receptor (CAR) that binds covalently modified mAbs to control Treg activation in vivo. Transient expression of this mAb-directed CAR (mAbCAR) in Tregs permitted Treg targeting to specific tissue sites and mitigated allograft responses, such as graft-versus-host disease. mAbCAR Tregs targeted to MHC class I proteins on allografts prolonged islet allograft survival and also prolonged the survival of secondary skin grafts specifically matched to the original islet allograft. Thus, transient genetic modification to produce mAbCAR T cells led to durable immune modulation, suggesting therapeutic targeting strategies for controlling alloreactivity in settings such as organ or tissue transplantation.
Antonio Pierini, Bettina P. Iliopoulou, Heshan Peiris, Magdiel Pérez-Cruz, Jeanette Baker, Katie Hsu, Xueying Gu, Ping-Ping Zheng, Tom Erkers, Sai-Wen Tang, William Strober, Maite Alvarez, Aaron Ring, Andrea Velardi, Robert S. Negrin, Seung K. Kim, Everett H. Meyer
mAbCAR construct and its expression in transfected T cells and Tregs.