Fei Liu, PhD

Education and Training

• The 4th Military Medical University, China, MB, 1995
• The 4th Military Medical University, China, PhD, 2002
• University of Dundee/Aberdeen, Scotland, Postdoc, 2005
• University of Pennsylvania, USA, Postdoc, 2008

Research Interests

• The characterization and application of mesenchymal stem cells (MSCs) derived from iPS cells and their extracellular vesicles (EVs). MSCs have many potential therapeutic applications, but tissue-derived MSCs show high donor variations and low expandability, which hinders their applications. To circumvent these issues, I derived MSCs from transgene-free human iPS cells efficiently with an optimized and scalable protocol. These iPSC-derived MSCs show biological activities comparable or superior to tissue-derived MSCs. I found recently that extracellular vesicles from iPSC-MSCs inhibit the progression of Sjogren’s syndrome, an autoimmune disease affecting salivary and tear glands. Meanwhile, extracellular vesicles mimics made from these cells target metastatic prostate and breast cancer specifically and improve treatment of these lethal cancers.
• Roles of tissue-resident macrophages in the development, homeostasis, and regeneration of salivary glands. Salivary gland destruction is a major adverse effect of radiotherapy for head and neck cancer. Consequent dry mouth severely compromises quality of life in these patients and is difficult to remedy. I discovered that Wnt and Hedgehog signaling are related with salivary gland regeneration, whereas transient activation of Wnt or Hedgehog signaling prevented or rescued radiation-induced hypofunction of salivary glands. My recent findings show Hedgehog activation rescues salivary function mainly through resident macrophages, and these cells are promising targets for preventing or treating dry mouth caused by radiotherapy. Moreover, these cells regulate development and immune homeostasis of salivary glands, which make them promising targets for treating salivary gland diseases caused by over-activation of immune system such as Sjogren’s syndrome and side effects of immune checkpoint inhibitors.