Targeted depletion of PD-1–expressing cells induces immune tolerance through peripheral clonal deletion
Jikai Cui, Heng Xu, Jizhang Yu, Shuan Ran, Xi Zhang, Yuan Li, Zhang Chen, Yuqing Niu, Song Wang, Weicong Ye, Wenhao Chen, Jie Wu, Jiahong Xia
Abstract
Thymic negative selection of the T cell receptor (TCR) repertoire is essential for establishing self-tolerance and acquired allograft tolerance following organ transplantation. However, it is unclear whether and how peripheral clonal deletion of alloreactive T cells induces transplantation tolerance. Here, we establish that programmed cell death protein 1 (PD-1) is a hallmark of alloreactive T cells and is associated with clonal expansion after alloantigen encounter. Moreover, we found that diphtheria toxin receptor (DTR)–mediated ablation of PD-1 + cells reshaped the TCR repertoire through peripheral clonal deletion of alloreactive T cells and promoted tolerance in mouse transplantation models. In addition, by using PD-1–specific depleting antibodies, we found that antibody-mediated depletion of PD-1 + cells prevented heart transplant rejection and the development of experimental autoimmune encephalomyelitis (EAE) in humanized PD-1 mice. Thus, these data suggest that PD-1 is an attractive target for peripheral clonal deletion and induction of immune tolerance.