Prevention of allograft rejection in heart transplantation through concurrent gene silencing of TLR and Kinase signaling pathways

Hongmei Wang; Xusheng Zhang; Xiufen Zheng; Zhu Lan; Jun Shi; Jifu Jiang; Terry Zwiep; Qing Li; Douglas Quan; Zhu-Xu Zhang; Weiping Min

doi:10.1038/srep33869

Prevention of allograft rejection in heart transplantation through concurrent gene silencing of TLR and Kinase signaling pathways

Sci Rep. 2016 Sep 23:6:33869. doi: 10.1038/srep33869.

Authors

Hongmei Wang^{1

2

3}, Xusheng Zhang^{2

3}, Xiufen Zheng^{2

3}, Zhu Lan³, Jun Shi¹, Jifu Jiang³, Terry Zwiep^{2

3}, Qing Li^{1

2}, Douglas Quan^{2

3}, Zhu-Xu Zhang^{1

2

3}, Weiping Min^{1

2

3}

Affiliations

¹ Institute of Immunotherapy and Medical College of Nanchang University, and Jiangxi Academy of Medical Sciences, Nanchang, China.
² Department of Surgery, Pathology, and Oncology, University of Western Ontario, London, Canada.
³ Multi-Organ Transplant Program, London Health Sciences Centre, London, Canada.

Abstract

Toll-like receptors (TLRs) act as initiators and conductors responsible for both innate and adaptive immune responses in organ transplantation. The mammalian target of rapamycin (mTOR) is one of the most critical signaling kinases that affects broad aspects of cellular functions including metabolism, growth, and survival. Recipients (BALB/c) were treated with MyD88, TRIF and mTOR siRNA vectors, 3 and 7 days prior to heart transplantation and 7, 14 and 21 days after transplantation. After siRNA treatment, recipients received a fully MHC-mismatched C57BL/6 heart. Treatment with mTOR siRNA significantly prolonged allograft survival in heart transplantation. Moreover, the combination of mTOR siRNA with MyD88 and TRIF siRNA further extended the allograft survival; Flow cytometric analysis showed an upregulation of FoxP3 expression in spleen lymphocytes and a concurrent downregulation of CD40, CD86 expression, upregulation of PD-L1 expression in splenic dendritic cells in MyD88, TRIF and mTOR treated mice. There is significantly upregulated T cell exhaustion in T cells isolated from tolerant recipients. This study is the first demonstration of preventing immune rejection of allogeneic heart grafts through concurrent gene silencing of TLR and kinase signaling pathways, highlighting the therapeutic potential of siRNA in clinical transplantation.